Reactivity of a Lewis Base Supported Thorium Terminal Imido

Article pubs.acs.org/Organometallics

Reactivity of a Lewis Base Supported Thorium Terminal Imido Metallocene toward Small Organic Molecules Congcong Zhang,†,§ Pikun Yang,†,§ Enwei Zhou,† Xuebin Deng,† Guofu Zi,*,† and Marc D. Walter*,‡ †

Department of Chemistry, Beijing Normal University, Beijing 100875, China Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany

‡

S Supporting Information *

ABSTRACT: The Lewis base supported thorium terminal imido metallocene (η5-C5Me5)2ThN(mesityl)(DMAP) (1) reacts with various small organic molecules such as thiazoles, silanes, internal acetylenes, nitriles, ketones, CS2, isothiocyanates, carbodiimides, lactides, organic azides, and diazoalkane derivatives. For example, while 1 forms the adduct (η5C5Me5)2ThN(mesityl)(OPPh3) (2) with Ph3PO, deprotonation occurs between 1 and thiazole to give the amido thiazolyl complex (η5-C5Me5)2Th(NHmesityl)(C3H2NS) (3). Moreover, the five-membered metallaheterocycle (η5-C5Me5)2Th[κ2-N,C{N(2-CH2-4,6-Me2C6H2)(SiH2Ph)}](DMAP) (4) is isolated from a mixture of 1 and PhSiH3. In addition, treatment of 1 with PhCN, Ph2CHCN, or Me3SiCN gives the zwitterionic complex (η5-C5Me5)2Th[κ-N-{NCPh(N(mesityl))}](DMAP) (5), and iminato compounds (η5-C5Me5)2Th[N(mesityl)C(CHPh2)NH](NCCPh2) (6) and (η5-C5Me5)2Th[2-{NC(SiMe3)}-4-Me2NC5H3N](NC) (7), respectively. Furthermore, reaction of 1 with PhCCMe and Me3SiCCCCSiMe3 afford the amido pyridyl complexes (η5-C5Me5)2Th[N(mesityl)C(Me) CHPh](κ2-C,N-4-Me2NC5H3N) (8) and (η5-C5Me5)2Th[N(mesityl)C(C2SiMe3)CHSiMe3](κ2-C,N-4-Me2NC5H3N) (9), respectively. Treatment of 1 with N,N′-diisopropylcarbodiimide furnishes the [2 + 2] cycloaddition product (η5C5Me5)2Th[N(mesityl)C(NiPr)-NiPr](DMAP) (10), whereas reaction of 1 with CS2 or PhNCS affords the four-membered metallaheterocycles (η5-C5Me5)2Th[SCN(mesityl)-S](DMAP) (11) and (η5-C5Me5)2Th[SCN(mesityl)-NPh](DMAP) (12), respectively. Moreover, while the four-membered metallaheterocycle (η5-C5Me5)2Th[(μ-O)2(CPh2)](DMAP) (13) is formed upon addition of Ph2CO to 1, deprotonation occurs between 1 and 1-indanone to give the amido enolyl compound (η5C5Me5)2Th(NH(mesityl))(κ-O-1-OC9H7) (14). Nevertheless, the eight-membered metallaheterocycle (η5-C5Me5)2Th[OCH(Me)C(O)OCH(Me)C(N(mesityl))O] (15) is isolated from reaction of 1 with rac-lactide. Furthermore, while mixing 1 with (p-tolyl)N3 affords the tetraazametallacyclopentene (η5-C5Me5)2Th[N(p-tolyl)NNN(p-tolyl)] (16), reaction of 1 with Me3SiCHN2 forms the bimetallic complex [(η5-C5Me5)2Th]2(μ-NNNCSiMe3)2 (17) concomitant with the elimination of mesitylene. The new complexes 2−15 and 17 were characterized by various spectroscopic techniques, including single-crystal Xray diffraction studies.

■

free terminal thorium imido complex [η 5 -1,2,4(Me3C)3C5H2]2ThN(p-tolyl) and the Lewis base supported terminal thorium imido complex (η5-C5Me5)2ThN(mesityl)(DMAP) (1) were prepared.8,9 The base-free complex [η51,2,4-(Me3C)3C5H2]2ThN(p-tolyl) reacts with various small molecules such as elemental sulfur (S8) and selenium (Se), silanes, borane, internal acetylenes, nitriles, ketones, CS2, isothiocyanates, carbodiimides, organic azides, and diazoalkane derivatives,8 whereas thorium−copper heterobimetallic compounds can be isolated from the reaction of (η5-C5Me5)2Th N(mesityl)(DMAP) (1) with copper(I) halides.9 It is obvious

INTRODUCTION In the last two decades, terminal imido complexes of actinidemetals containing an AnN double bond have been extensively investigated and their potential application in group transfer reactions and catalysis has been explored.1−4 However, these investigations have mainly been focused on uranium imido compounds,1−4 whereas studies on thorium imido complexes are still limited.3j,4 The electronic ground state [Rn] 6d27s2 of the thorium atom resembles that of early d transition metals, for which compounds with MN bonds are well-known,5,6 and similar reactivity may be expected. Nevertheless, more recent experimental and computational studies suggest that the 5f orbitals also modulate the bonding and reactivity of organothorium compounds, which results in distinctively different reactivity patterns in comparison to group 4 complexes.7 To probe for these differences, the base© XXXX American Chemical Society

Special Issue: Organometallic Actinide and Lanthanide Chemistry Received: March 19, 2017

A

DOI: 10.1021/acs.organomet.7b00212 Organometallics XXXX, XXX, XXX−XXX

Article

Organometallics

datively coordinated oxygen atom. The short Th−N distance of 2.075(4) Å and the approximately linear Th−N−C angle (179.2(4)°) are consistent with a ThN double bond,10 and they are close to those found in (η5-C5Me5)2ThN(2,6Me2C6H3)(thf) with a Th−N distance of 2.045(8) Å and a Th−N−C angle of 171.5(7)°,4a [η5-1,2,4-(Me3C)3C5H2]2Th N(p-tolyl) with a Th−N distance of 2.038(3) Å and a Th−N− C angle of 172.8(3)°,8b and 1 with a Th−N distance of 2.091(7) Å and a Th−N−C angle of 167.2(6)°.9 However, no thiazole imido adduct is formed on addition of thiazole to 1; instead, the amido thiazolyl complex (η5-C5Me5)2Th(NH(mesityl))(C3H2NS) (3) is isolated (Scheme 1). We assume that thiazole replaces the coordinated DMAP to give a thiazole imido adduct, which converts to product 3 by deprotonation of the coordinated thiazole (Scheme 1). The molecular structure of 3 is shown in Figure 2, and selected bond distances and angles are given in Table 1. The relatively long Th−N(2) distance of 2.482(7) Å is again indicative of a datively coordinated nitrogen atom, but it is shorter than that found in 1 (2.554(7) Å).9 The Th−N(1) distance of 2.313(6) Å is in the same range as that found in (η5-C5Me5)2Th(NH(mesityl))2 (2.344(12) Å),9 whereas the Th−C(30) distance of 2.493(8) Å is essentially identical with that found in [η 5 -1,2,4(Me3C)3C5H2]2Th(NH-p-tolyl)(η2-C,N-C5H4N) (2.486(5) Å).8f Reaction with Silane. In analogy to scandium5h and titanium6l,m imido complexes, the Si−H bond of silane can also be cleaved by the thorium imido complex 1. For example, treatment of imido 1 with 1 equiv of PhSiH3 forms the fivemembered metallaheterocycle (η5-C5Me5)2Th[κ2-N,C-{N(2CH2-4,6-Me2C6H2)(SiH2Ph)}](DMAP) (4) concomitant with H2 release (Scheme 2). Analogous to the reaction of the thorium imido complex [η5-1,2,4-(Me3C)3C5H2]2ThN(ptolyl) with PhSiH3,8d we propose that complex 1 initially reacts with PhSiH3 to give the amido hydrido complex (η5C5Me5)2Th(H)[N(mesityl)SiH2Ph]. However, in contrast to the more sterically encumbered amido hydrido complex [η51,2,4-(Me3C)3C5H2]2Th(H)[N(p-tolyl)SiH2Ph] formed from [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) and PhSiH3,8d the amido hydrido intermediate (η5-C5Me5)2Th(H)[N(mesityl)SiH2Ph] is reactive and converts to the final product 4 via C−H activation of the mesityl group concomitant with H2 release (Scheme 2). This change can be traced to the more open coordination sphere in the Cp* derivative and also to the fact that the benzylic Me groups of the mesityl moiety are more acidic than the aromatic C−H bonds of a phenyl substituent. The molecular structure of 4 is shown in Figure 3, and selected bond distances and angles can be found in Table 1. The relatively long Th−N(2) distance of 2.694(4) Å implies a dative coordination of the nitrogen atom, but the distance is longer than that found in the starting material 1 (2.554(7) Å).9 The Th−N(1) distance of 2.410(4) Å is elongated relative to those found in the metallocene bis(amides) [η 5 -1,2,4(Me3C)3C5H2]2Th(HNMe)2 (2.255(4) and 2.227(4) Å),8b [η 5 -1,2,4-(Me 3 C) 3 C 5 H2 ] 2Th(HN-p-tolyl) 2 (2.279(3) and 2.286(3) Å),8b and (η5-C5Me5)2Th(NHmesityl)2 (2.344(12) Å),9 which may be attributed to enhanced steric hindrance between the more bulky chelating amido ligand and the metallocene fragment. In contrast, the Th−C(35) distance of 2.532(6) Å lies in the same range as the average Th−C(Me) distances found in the dimethyl metallocenes (η 5 C5Me5)2ThMe2 (2.475(9) Å),11a [η5-1,2,4(Me 3 C) 3 C 5 H 2 ] 2 ThMe 2 (2.480(3) Å), 8b and [η 5 -1,3-

that the substituents on the Cp and imido ligands will influence the reactivity of the actinide imido moiety, but the effects may be subtle. As part of these investigations, we describe herein some transformations of small organic molecules on exposure to the Lewis base supported imido thorium metallocene (η5C5Me5)2ThN(mesityl)(DMAP) (1).

■

RESULTS AND DISCUSSION Reaction with Lewis Bases. The coordinated 4(dimethylamino)pyridine (DMAP) ligand in the thorium imido complex (η5-C5Me5)2ThN(mesityl)(DMAP) (1) can be replaced by other Lewis bases. For example, ligand exchange is observed between complex 1 and Ph3PO to form the adduct (η5-C5Me5)2ThN(mesityl)(OPPh3) (2) (Scheme 1). The Scheme 1

solid-state crystal structure of 2 is shown in Figure 1, and selected bond distances and angles are given in Table 1. The relatively long Th−O distance of 2.466(4) Å indicates a

Figure 1. Molecular structure of 2 (thermal ellipsoids drawn at the 35% probability level). B


Article

Organometallics Table 1. Selected Distances (Å) and Angles (deg) for Compounds 2−15 and 17a compound

C(Cp)−Thb

2 3

2.884(6) 2.814(8)

4

C(Cp)−Thc

Cp(cent)−Thb

Th−X

2.834(5)−2.948(6) 2.766(7)−2.848(8)

2.619(6) 2.546(8)

2.865(5)

2.820(5)−2.935(5)

2.599(5)

5 6

2.845(7) 2.816(7)

2.810(6)−2.894(7) 2.774(7)−2.875(6)

2.578(7) 2.547(7)

7

2.808(14)

2.774(12)−2.836(14)

2.534(14)

8

2.864(5)

2.828(5)−2.927(5)

2.600(5)

9

2.866(4)

2.833(4)−2.923(4)

2.600(4)

10

2.890(6)

2.829(6)−2.920(5)

2.628(6)

11 12 13

2.829(7) 2.834(14) 2.873(4)

2.784(7)−2.879(6) 2.792(14)−2.887(11) 2.830(4)−2.915(4)

2.561(7) 2.576(14) 2.609(4)

14 15

2.827(6) 2.813(5)

2.803(6)−2.864(5) 2.788(5)−2.847(5)

2.557(6) 2.542(5)

17

2.814(6)

2.775(6)−2.874(6)

2.544(6)

N(1) 2.075(4), O(1) 2.466(4) N(1) 2.313(6), N(2) 2.482(7), C(30) 2.493(8) N(1) 2.410(4), N(2) 2.694(4), C(35) 2.532(6) N(1) 2.545(5), N(3) 2.107(6) N(1) 2.555(5), N(2) 2.422(6), N(3) 2.401(6) N(1) 2.542(14), N(2) 2.300(11), N(3) 2.603(12) N(1) 2.436(4), N(3) 2.464(4), C(21) 2.450(5) N(1) 2.434(3), N(2) 2.415(3), C(40) 2.450(4) N(1) 2.624(5), N(3) 2.423(4), N(5) 2.368(5) N(1) 2.597(6), S(1) 2.821(2), S(2) 2.789(2) N(1) 2.429(8), N(3) 2.635(9), S(1) 2.790(3) N(1) 2.611(4), O(1) 2.244(3), O(2) 2.256(3) N(1) 2.328(5), O(1) 2.194(4) O(1) 2.302(3), O(2) 2.612(3), O(4) 2.186(3) N(1) 2.443(5), N(3A) 2.462(6), C(21) 2.320(5)

Cp(cent)−Th− Cp(cent)

X−Th−X/Y

129.5(2) 134.9(2)

103.0(2) 30.8(2)d

129.4(2)

67.4(2)e

134.9(2) 129.6(2)

98.5(2) 53.4(2)f

142.2(4)

64.5(2)g

127.5(1)

32.3(1)h

128.2(1)

32.0(1)i

126.9(2)

56.9(2)j

136.5(1) 131.7(2) 130.7(1)

64.2(1)k 60.7(2)l 61.0(1)m

132.0(2) 132.7(1)

116.4(2) 122.8(1)n

130.1(2)

77.3(2)o, 36.5(2)p

a Cp = cyclopentadienyl ring. bAverage value. cRange. dThe C(30)−Th(1)−N(2) angle. eThe C(35)−Th(1)−N(1) angle. fThe N(1)−Th(1)−N(2) angle. gThe N(2)−Th(1)−N(3) angle. hThe C(21)−Th(1)−N(1) angle. iThe C(40)−Th(1)−N(2) angle. jThe N(3)−Th(1)−N(5) angle. kThe S(1)−Th(1)−S(2) angle. lThe S(1)−Th(1)−N(1) angle. mThe O(1)−Th(1)−O(2) angle. nThe O(1)−Th(1)−O(4) angle. oThe N(1)−Th(1)− N(3A) angle. pThe C(21)−Th(1)−N(1) angle.

Scheme 2

Figure 2. Molecular structure of 3 (thermal ellipsoids drawn at the 35% probability level).

(Me3C)2C5H3]2ThMe2 (2.542(5) Å)8b and the averaged Th− C(CH2) distances observed for the dibenzyl metallocenes [η51,2,4-(Me3C)3C5H2]2Th(CH2Ph)2 (2.524(3) Å),11b [η5-1,3(Me 3 C) 2 C 5 H 3 ] 2 Th(CH 2 Ph) 2 (2.52(2) Å), 11b and (η 5 C5Me5)2Th(CH2Ph)2 (2.552(7) Å).11a Reaction with Nitriles. Unlike the reaction of the thorium imido complex [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) with PhCN,8b the reaction of complex 1 with PhCN does not stop at the [2 + 2] cycloaddition product; instead, the zwitterionic complex (η5-C5Me5)2Th[κ-N-{NCPh(N(mesityl))}](DMAP) (5) is formed in quantitative conversion (Scheme 2), which is presumably a consequence of the more bulky mesityl substituent. Figure 4 shows the molecular structure of 5,

whereas relevant bond distances and angles can be found in Table 1. The C(28)−N(3) distance of 1.311(8) Å is only slightly shorter than that of C(28)−N(4) (1.337(8) Å), which suggests delocalization of the negative charge within this moiety. Nitrogen atom N(1) coordinates datively to the Th(IV) atom (2.545(5) Å), similar to the situation found in 1 C


Article

Organometallics Scheme 3



(2.554(7) Å).9 However, the very short Th−N(3) distance (2.107(6) Å) and the Th−N(3)-C(28) angle (163.5(5)°) suggest some nitrogen π donation to the thorium atom.8b These structural parameters may be compared to those found in [η 5-1,2,4-(Me 3C) 3C 5H2]2Th[η 2-NN(p-tolyl)][NC(C12H8)] with a Th−N distance of 2.275(2) Å and a Th− N−C angle of 161.6(2)°,8e (η5-C5Me5)2Th[NC(C12H8)]2 with Th−N distances of 2.280(14) and 2.269(12) Å and Th− N−C angles of 172.1(12) and 174.7(15)°,12 and imidazolin-2iminato thorium compounds with Th−N distances of 2.176(8)−2.235(9) Å and Th−N−C angles of 156.1(5)173.7(4)°.13 Furthermore, reaction of complex 1 with Ph2CHCN yields the iminato compound (η5-C5Me5)2Th[N(mesityl)C(CHPh2)NH](NCCPh2) (6) in quantitative conversion along with DMAP loss (Scheme 3). A plausible reaction mechanism for this product formation involves a [2 + 2] addition to form a four-membered complex with DMAP release, and this four-membered intermediate further reacts with a second molecule of Ph2CHCN to give the final product 6, in which an α-H of Ph2CHCN is transferred to the fourmembered Th[N(mesityl)C(CHPh2)N] moiety (Scheme 3). The molecular structure of 6 is presented in Figure 5, and selected bond distances and angles are provided in Table 1. The C(44)−N(3) distance is 1.194(9) Å, whereas the C(44)− C(45) distance is 1.365(10) Å. The Th−N(1) distance of 2.555(5) Å is longer than those of Th−N(2) (2.422(6) Å) and Th−N(3) (2.401(6) Å), presumably as a consequence of the


bulky mesityl group. However, when complex 1 is treated with Me3SiCN, the isocyanido iminato complex (η5-C5Me5)2Th[2{NC(SiMe3)}-4-Me2NC5H3N](NC) (7) can be isolated, which is probably formed from the amido pyridyl isomer (η5C5Me5)2Th(NH(mesityl))(κ2-C,N-4-Me2NC5H3N) (1′).9 As previously shown, complex 1 is in equilibrium with its amido pyridyl isomer (η 5 -C 5 Me 5 ) 2 Th(NH(mesityl))(κ 2 -C,N-4Me2NC5H3N) (1′),9 and it can be envisioned that 1′ reacts with 1 equiv of Me3SiCN to furnish an isocyanido pyridyl intermediate concomitant with (mesityl)NH(SiMe3) release. After the insertion of a second molecule of Me3SiCN into the Th−pyridyl moiety the final product 7 can be isolated (Scheme 4). The molecular structure of 7 is shown in Figure 6, and selected bond distances and angles are given in Table 1. Nitrogen atom N(3) coordinates datively to the Th(IV) atom, as indicated by a relatively long Th−N(3) distance of 2.603(12) Å, which is slightly longer than that found in 1 (2.554(7) Å).9 The Th−N(2) distance of 2.300(11) Å is also elongated relative to that found in 5 (2.107(6) Å). Both D


Article

Organometallics Scheme 4

Scheme 5

imido complex [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl),8b no reaction is observed for complex 1 and PhCCPh even when the reaction mixture is heated at 100 °C for 1 week, which can also be explained on the basis of the steric arguments outlined above. The molecular structures of 8 and 9 are shown in Figures 7 and 8, and selected bond distances and angles are


observations can be attributed to the more sterically encumbered chelating iminato ligand. The Th−N(1) distance of 2.542(14) Å is intermediate to those found in [η5-1,2,4(Me3C)3C5H2]2Th(OSiMe3)(NC) (2.454(4) Å),8a bis(NHC)borate isocyanido thorium complexes (2.48(1)−2.494(5) Å), 14a and isocyanido/cyanido thorocene complexes (2.609(3)−2.648(4) Å).14b Reaction with Internal Alkynes. Unlike the reaction of the thorium imido complex [η5-1,2,4-(Me3C)3C5H2]2Th N(p-tolyl) with internal alkynes,8b the [2 + 2] cycloaddition products are not isolated from the reaction of imido complex 1 with 1 equiv of PhCCMe or Me3SiCCCCSiMe3, instead, the amido pyridyl compounds (η5-C5Me5)2Th[N(mesityl)C(Me)CHPh](κ2-C,N-4-Me2NC5H3N) (8) and (η5-C5Me5)2Th[N(mesityl)C(C2SiMe3)CHSiMe3](κ2-C,N4-Me2NC5H3N) (9) are formed, respectively (Scheme 5). A plausible reaction mechanism involves initial [2 + 2] cycloaddition in the reaction of 1 with PhCCMe or Me3SiC CCCSiMe3, followed by deprotonation of an α-H of DMAP to yield the final products 8 and 9, respectively (Scheme 5). In principle, two isomers could be formed in this transformation, but in both cases only one isomer, 8 or 9, can be detected by 1 H NMR spectroscopy. Steric repulsion between the mesityl group and the incoming alkyne determines the selectivity of this reaction. It is also of note that, in contrast to the thorium


given in Table 1. The Th−N distances for 8 (2.436(4) and 2.464(4) Å) and 9 (2.434(3) and 2.415(3) Å) are in a similar range, whereas the Th−C(21) distance of 2.450(5) Å for 8 is identical with that found in 9 (Th−C(40) 2.450(4) Å). However, when complex 1 is treated with a simple alkene such as CH2CH2 or cis-PhCHCHPh, no reaction occurs even when the reaction mixture is heated at 100 °C for 1 week. Reaction with Carbodiimides, CS2, and Isothiocyanates. In analogy to the imido complex [η 5 -1,2,4(Me3C)3C5H2]2ThN(p-tolyl),8d the imido compound 1 can also react with carbodiimides. For example, treatment of 1 with E


Article

Organometallics



1 equiv of N,N′-diisopropylcarbodiimide furnishes the fourmembered metallaheterocycle (η5-C5Me5)2Th[N(mesityl)C(NiPr)-NiPr](DMAP) (10) in quantitative conversion (Scheme 6). The molecular structure of 10 can be found in Scheme 6


C5Me5)2ThS2(DMAP) (2.714(3) Å).15 In a related reaction, complex 1 reacts with PhNCS to form a [2 + 2] cycloaddition complex, which then converts via a [1,3]-Th migration to the four-membered metallaheterocycle (η5-C5Me5)2Th[SCN(mesityl)-NPh](DMAP) (12) (Scheme 6). The molecular structure of 12 is shown in Figure 11, and selected bond

Figure 9, and selected bond distances and angles are given in Table 1. The long Th−N(1) distance of 2.624(5) Å is in the typical regime of nitrogen atoms datively coordinated to Th(IV), whereas the Th−N(3) distance (2.423(4) Å) is comparable to that of Th−N(5) (2.368(5) Å). However, the four-membered metallaheterocycle (η5-C5Me5)2Th[SCN(mesityl)-S](DMAP) (11) is isolated from the reaction of complex 1 and CS2 (Scheme 6). Formation of 11 may be explained by an initial [2 + 2] cycloaddition of 1 with CS2, followed by a [1,3]-Th migration (Scheme 6). The molecular structure of 11 can be found in Figure 10, and selected bond distances and angles are provided in Table 1. The long Th− N(1) distance of 2.597(6) Å implies again a dative coordination of the nitrogen atom, whereas the average Th−S distance of 2.805(2) Å is longer than t hat found in ( η 5 -


distances and angles are given in Table 1. The Th−N(1) distance is 2.429(8) Å, whereas the Th−S distance of 2.790(3) Å is close to the average Th−S distance (2.805(2) Å) found in 11. Reaction with Ketones and Lactide. In contrast to the reaction of complex 1 with N,N′-diisopropylcarbodiimide, F


Article

Organometallics

1,2,4-(Me3C)3C5H2]2Th[(μ-O)2(CPh2)] (2.202(3) Å).8a However, treatment of complex 1 with 1-indanone affords the amido enolyl complex (η5-C5Me5)2Th(NH(mesityl))(κ-O-1-OC9H7) (14), in which an α-H of 1-indanone is transferred to the imido ThN(mesityl) moiety (Scheme 8). The molecular structure

complex 1 forms the four-membered metallaheterocycle (η5C 5 Me 5 ) 2 Th[(μ-O) 2 (CPh 2 )](DMAP) (13) with Ph 2 CO (Scheme 7). In analogy to the reaction of the thorium imido Scheme 7

Scheme 8

complex [η 5 -1,2,4-(Me 3 C) 3 C 5 H 2 ] 2 ThN(p-tolyl) with Ph2CO,8a it may be suggested that complex 1 undergoes an initial [2 + 2] cycloaddition with Ph2CO to form a fourmembered metallaheterocycle, but this intermediate is unstable and converts to the thorium oxido complex (η5-C5Me5)2ThO(DMAP) by elimination of (mesityl)NCPh2. However, unlike the more sterically encumbered actinide oxido derivatives [η5-1,2,4-(Me3C)3C5H2]2AnO(DMAP) (An = Th, U),3m,8a the Cp* ligand lacks sufficient steric demand to stabilize the oxido intermediate (η5-C5Me5)2ThO(DMAP), which immediately reacts with a second molecule of Ph2CO to give the final product 13 (Scheme 7). The molecular structure of 13 is shown in Figure 12, and selected bond distances and angles are given in Table 1. The Th−N(1) distance of 2.611(4) Å is in the typical range expected for a datively coordinated nitrogen atom, whereas the average Th−O distance of 2.250(3) Å is slightly longer than that found in [η5Figure 13. Molecular structure of 14 (thermal ellipsoids drawn at the 35% probability level).

of 14 is shown in Figure 13, and selected bond distances and angles are provided in Table 1. The Th−N(1) distance of 2.328(5) Å is close to that found in (η5-C5Me5)2Th(NH(mesityl))2 (2.344(12) Å),9 whereas the Th−O(1) distance of 2.194(4) Å is shorter than the average Th−O distance (2.250(3) Å) found in 13. Moreover, no [2 + 2] cycloaddition product is isolated from the reaction of complex 1 with raclactide; instead, the eight-membered metallaheterocycle (η5C5Me5)2Th[OCH(Me)C(O)OCH(Me)C(N(mesityl))O] (15) is formed with DMAP release (Scheme 8). The formation of 15 presumably includes a nucleophilic attack, followed by κN → κO isomerization (Scheme 8). The

Figure 12. Molecular structure of 13 (thermal ellipsoids drawn at the 35% probability level). G


Article

Organometallics

(mesityl)N3 elimination. However, the Cp* ligand lacks sufficient steric demand to stabilize this imido intermediate, which then readily reacts with a second molecule of (p-tolyl)N3 in a [2 + 3] cycloaddition reaction to form product 16 (Scheme 9). Nevertheless, in contrast to the reaction of the thorium imido complex [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) with diazoalkane Me3SiCHN2,8e no amido nitrilimido complex is formed; instead, the bimetallic complex [(η5-C5Me5)2Th]2(μNNNCSiMe3)2 (17) is isolated (Scheme 10). We propose

molecular structure of 15 is presented in Figure 14, and selected bond distances and angles are given in Table 1. The

Scheme 10


relatively long Th−O(2) distance of 2.612(3) Å is consistent with a datively coordinated oxygen atom, whereas the Th− O(4) distance of 2.186(3) Å is shorter than that of Th−O(1) (2.302(3) Å) but close to that found in 14 (2.194(4) Å). Reaction with Organic Azides and Diazoalkane Derivatives. Complex 1 also reacts with organic azides. For example, treatment of 1 with (p-tolyl)N3 results in the formation of the tetraazametallacyclopentene (η5-C5Me5)2Th[N(p-tolyl)NNN(p-tolyl)] (16) (Scheme 9). In analogy to Scheme 9

that complex 1 reacts with Me3SiCHN2 to give a threemembered complex and free DMAP; the three-membered intermediate converts to a mesityl complex by [1,3]-C migration. Then the mesityl complex immediately undergoes an inter- or intramolecular deprotonation of an α-H of the Me3SiCHN3 group to yield a zwitterionic species and mesitylene. Finally, the zwitterionic complex dimerizes to 17 (Scheme 10). The molecular structure of 17 is shown in Figure 15, while relevant bond distances and angles are given in Table 1. The Th−N(1) distance of 2.443(5) Å is comparable to that of Th−N(3A) (2.462(6) Å), whereas the Th−C(21) distance of 2.320(5) Å is on the lower end of the reported Th−C(sp2) σ bonds (2.395(2)−2.654(14) Å).7f,j−l,8d,16

■

CONCLUSIONS In conclusion, analogous to [η5-1,3-(Me3C)2C5H3]2ThN(ptolyl),8 the thorium terminal imido complex (η5-C5Me5)2Th N(mesityl) (DMAP) (1) shows a broad reactivity toward small organic molecules, but their reactivity patterns diverge. Complex 1 reacts with carbodiimides, CS2, isothiocyanates, ketones, organic azides, silanes, lactides, thiazoles, nitriles, and internal acetylenes, leading to the formation of four-, five-, and eight-membered heterometallacycles, amido enolyl complexes, amido thiazolyl complexes, iminato complexes, and amido pyridyl complexes. Furthermore, the bimetallic complex [(η5-

the reaction of the thorium imido complex [η5-1,2,4(Me3C) 3C5H2]2ThN(p-tolyl) with (p-tolyl)N3,8e it is suggested that complex 1 reacts with (p-tolyl)N3 to give a five-membered tetraazametallacyclopentene with concomitant DMAP release. To reduce the steric hindrance, the tetraazametallacyclopentene intermediate then converts to the thorium imido complex (η5-C5Me5)2ThN(p-tolyl) by H


Organometallics

■

Article

EXPERIMENTAL SECTION

General Procedures. All reactions and product manipulations were carried out under an atmosphere of dry dinitrogen with rigid exclusion of air and moisture using standard Schlenk or cannula techniques, or in a glovebox. All organic solvents were freshly distilled from sodium benzophenone ketyl immediately prior to use. (ptolyl)N317 and (η5-C5Me5)2ThN(mesityl)(DMAP) (1)9 were prepared according to literature methods. All other chemicals were purchased from Aldrich Chemical Co. and Beijing Chemical Co. and used as received unless otherwise noted. Infrared spectra were obtained from KBr pellets on an Avatar 360 Fourier transform spectrometer. 1H, 13C{1H}, and 31P{1H} NMR spectra were recorded on a Bruker AV 400 spectrometer at 400, 100, and 162 MHz, respectively. All chemical shifts are reported in δ units referenced to the residual protons of the deuterated solvents, which are internal standards, for proton and carbon chemical shifts, and to external 85% H3PO4 (0.00 ppm) for phosphorus chemical shifts. Melting points were measured on an X-6 melting point apparatus and were uncorrected. Elemental analyses were performed on a Vario EL elemental analyzer. The bulk purity of new compounds was established by NMR spectroscopy and elemental analyses, unless stated otherwise. Preparation of (η5-C5Me5)2ThN(mesityl)(OPPh3) (2). A toluene (10 mL) solution of Ph3PO (56 mg, 0.20 mmol) was added to a toluene (10 mL) solution of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol). The mixture was stirred at room temperature overnight, and the solvent was removed under reduced pressure. The residue was extracted with benzene (10 mL × 3) and filtered. The volume of the filtrate was reduced to 3 mL; yellow crystals of 2 were isolated when this solution was kept at room temperature for 2 days. Yield: 170 mg (93%). Mp: 108−110 °C. 1H NMR (C6D6): δ 7.73 (m, 6H, phenyl), 7.01 (m, 11H, mesityl and phenyl), 2.88 (s, 3H, mesityl CH3), 2.47 (s, 3H, mesityl CH3), 2.22 (s, 3H, mesityl CH3), 2.12 (s, 30H, Cp CH3) ppm. 13C{1H} NMR (C6D6): δ 155.0 (mesityl C), 133.7 (s, phenyl C), 133.6 (s, phenyl C), 133.5 (d, JCP = 9.7 Hz, phenyl C), 129.4 (mesityl C), 128.9 (d, JCP = 12.5 Hz, phenyl C), 127.4 (mesityl C), 122.1 (ring C), 120.2 (mesityl C), 22.3 (mesityl CH3), 21.2 (mesityl CH3), 12.0 (CpCH3) ppm. 31 1 P{ H} NMR (C6D6): δ 40.4 (s) ppm. IR (KBr, cm−1): ν 2906 (m), 1591 (m), 1483 (m), 1438 (s), 1190 (s), 1120 (s), 1070 (m), 997 (m), 754 (s). Anal. Calcd for C47H56NOPTh: C, 61.76; H, 6.18; N, 1.53. Found: C, 61.75; H, 6.15; N, 1.55. Preparation of (η5-C5Me5)2Th(NH(mesityl))(C3H2NS) (3). Method A. This compound was obtained as colorless crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and thiazole (17 mg, 0.20 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 124 mg (86%). Mp: 110−112 °C. 1H NMR (C6D6): δ 7.65 (d, J = 2.8 Hz, 1H, thiazole), 7.54 (d, J = 2.7 Hz, 1H, thiazole), 6.98 (s, 2H, mesityl), 4.49 (s, 1H, NH), 2.51 (s, 6H, mesityl CH3), 2.38 (s, 3H, mesityl CH3), 1.87 (s, 30H, Cp CH3) ppm. 13C{1H} NMR (C6D6): δ 244.7 (ThC), 153.0 (thiazole C), 136.7 (thiazole C), 130.4 (mesityl C), 129.3 (mesityl C), 128.6 (mesityl C), 124.8 (mesityl C), 124.5 (ring C), 21.9 (mesityl CH3), 20.8 (mesityl CH3), 11.5 (CpCH3) ppm. IR (KBr, cm−1): ν 3104 (w), 2910 (s), 1608 (m), 1491 (s), 1440 (s), 1404 (s), 1252 (m), 1087 (s), 1059 (s), 1010 (s), 854 (s). Anal. Calcd for C32H44N2STh: C, 53.32; H, 6.15; N, 3.89. Found: C, 53.31; H, 6.16; N, 3.92. Method B: NMR Scale. A C6D6 (0.3 mL) solution of thiazole (1.7 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 3 and those of DMAP (1H NMR (C6D6): δ 8.47 (d, J = 6.3 Hz, 2H, py), 6.10 (d, J = 6.3 Hz, 2H, py), 2.22 (s, 6H, CH3) ppm) were observed by 1H NMR spectroscopy (100% conversion) in 10 min. Preparation of (η5-C5Me5)2Th[κ2-N,C-{N(2-CH2-4,6-Me2C6H2)(SiH2Ph)}](DMAP) (4). Method A. This compound was obtained as colorless crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and PhSiH3 (22 mg, 0.20 mmol) in


C5Me5)2Th]2(μ-NNNCSiMe3)2 (17) and mesitylene are formed when 1 is exposed to Me3SiCHN2. The observed reactivity is dominated by steric effects at the metallocene fragment, since the C5Me5 ligand provides a more open coordination sphere in comparison to the more sterically encumbered 1,2,4-(Me3C)3C5H2 derivative and therefore gives rise to more reactive intermediates. For example, while the thorium oxido complex [η5-1,2,4-(Me3C)3C5H2]2ThO(DMAP) can be isolated from the reaction of [η 5 -1,2,4(Me3C)3C5H2]2ThN(p-tolyl) with Ph2CO and DMAP,8a exposure of 1 to Ph2CO affords the four-membered metallaheterocycle (η5-C5Me5)2Th[(μ-O)2(CPh2)](DMAP) (13) with the elimination of (mesityl)NCPh2. However, the substituents on the imido moiety also modulate the reactivity of these Th imido compounds. For example, while the amido hydrido complex [η5-1,2,4-(Me3C)3C5H2]2Th(H)[N(p-tolyl)SiH2Ph] formed from [η5-1,2,4-(Me3C)3C5H2]2ThN(ptolyl) and PhSiH3 is stable,8d a C−H bond activation of the mesityl ligand occurs for that derived from 1 and PhSiH3. Mixing [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) with PhCN forms a [2 + 2] cycloaddition product, while exposure of 1 to PhCN affords the open zwitterionic complex (η5-C5Me5)2Th[κN-{NCPh(N(mesityl))}](DMAP) (5). Moreover, while complex 1 is inert to PhCCPh, a [2 + 2] cycloaddition occurs for [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) and PhCCPh.8b The four-membered metallaheterocycles [η 5 -1,2,4(Me3C)3C5H2]2Th[N(p-tolyl)C(E)-S] (E = S, PhN) formed from [η5-1,2,4-(Me3C)3C5H2]2ThN(p-tolyl) and CS2 or PhNCS are stable,8a whereas a [1,3]-Th migration is observed for those derived from 1 and CS2 or PhNCS. In addition, while the tetraazametallacyclopentene [η5-1,2,4-(Me3C)3C5H2]2Th[N(p-tolyl)NNN(p-tolyl)] formed from [η 5 -1,2,4(Me3C)3C5H2]2ThN(p-tolyl) and (p-tolyl)N3 is stable,8e NN cleavage and (mesityl)N3 elimination occur for that derived from 1 and (p-tolyl)N3. Furthermore, mixing [η5-1,2,4(Me3C)3C5H2]2ThN(p-tolyl) with diazoalkane Me3SiCHN2 forms the amido nitrilimid o co mplex [η 5 -1,2,4(Me3C)3C5H2]2Th(NH-p-tolyl)(N2CSiMe3)],8e while exposure of 1 to Me3SiCHN2 affords the bimetallic complex [(η5C5Me5)2Th]2(μ-NNNCSiMe3)2 (17) with the elimination of mesitylene. Further exploration of actinide imido complexes is ongoing, and the results will be reported in due course. I


Article

Organometallics

observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. Reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1) with Ph2CHCN: NMR Scale. A C6D6 (0.3 mL) solution of Ph2CHCN (3.9 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 6 along with those of unreacted 1 and DMAP were observed by 1H NMR spectroscopy (50% conversion based on 1) when this solution was kept at room temperature overnight. Preparation of (η 5 -C 5 Me 5 ) 2 Th[2-{N C(SiMe 3 )}-4Me2NC5H3N](NC)·C6H6 (7·C6H6). Method A. This compound was obtained as purple crystals from the reaction of (η5-C5Me5)2Th N(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and Me3SiCN (40 mg, 0.40 mmol) in toluene (15 mL) at 70 °C and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 151 mg (91%). Mp: 206−208 °C. 1H NMR (C6D6): δ 9.32 (d, J = 6.6 Hz, 1H, DMAP), 7.15 (s, 6H, C6H6), 6.50 (d, J = 2.7 Hz, 1H, DMAP), 5.46 (d, J = 4.1 Hz, 1H, DMAP), 2.10 (s, 30H, Cp CH3), 2.09 (s, 6H, N(CH3)2), 0.45 (s, 9H, Si(CH3)3) ppm. 13 C{1H} NMR (C6D6): δ 192.5 (NC), 162.8 (NC), 156.7 (py C), 153.6 (py C), 129.4 (py C), 128.6 (C6H6), 124.1 (ring C), 105.7 (py C), 104.4 (py C), 38.2 (N(CH3)2), 11.9 (CpCH3), −0.3 (SiCH3) ppm. IR (KBr, cm−1): ν 2902 (s), 2052 (m), 1610 (s), 1541 (s), 1435 (s), 1382 (s), 1259 (s), 1004 (s), 842 (s). Anal. Calcd for C38H54N4SiTh: C, 55.19; H, 6.58; N, 6.77. Found: C, 55.15; H, 6.61; N, 6.74. Method B: NMR Scale. A C6D6 (0.3 mL) solution of Me3SiCN (4.0 mg, 0.04 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 7 and those of (mesityl)NH(SiMe3)18 (1H NMR (C6D6): δ 6.82 (s, 2H, phenyl), 2.21 (s, 3H, CH3), 2.18 (s, 6H, CH3), 1.97 (s, 1H, NH), 0.08 (s, 9H, SiCH3) ppm) were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at 70 °C overnight. Preparation of (η5-C5Me5)2Th[N(mesityl)C(Me)CHPh](κ2C,N-4-Me2NC5H3N)·C6H6 (8·C6H6). Method A. This compound was obtained as colorless crystals from the reaction of (η5C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and PhCCMe (23 mg, 0.20 mmol) in toluene (15 mL) at 70 °C and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 168 mg (88%). Mp: 175−177 °C dec. 1H NMR (C6D6): δ 7.68 (d, J = 7.6 Hz, 2H, phenyl), 7.40 (t, J = 7.4 Hz, 2H, phenyl), 7.15 (s, 6H, C6H6), 7.07 (t, J = 7.0 Hz, 1H, phenyl), 6.87 (s, 2H, mesityl), 6.68 (s, 1H, DMAP), 6.22 (s, 1H, C CH), 5.93 (d, J = 4.6 Hz, 1H, DMAP), 2.34 (s, 3H, CCCH3), 2.31 (s, 6H, N(CH3)2), 2.13 (s, 6H, mesityl CH3), 2.11 (s, 30H, Cp CH3), 1.91 (s, 3H, mesityl CH3); one proton of DMAP was not observed. 13 C{1H} NMR (C6D6): δ 230.3 (Th C), 157.3 (aryl C), 154.5 (aryl C), 150.7 (aryl C), 143.8 (aryl C), 142.5 (aryl C), 135.0 (aryl C), 131.3 (aryl C), 128.9 (aryl C), 128.8 (aryl C), 128.6 (C6H6), 124.3 (aryl C), 124.0 (ring C), 122.6 (aryl C), 108.7 (CC), 107.7 (py), 97.5 (C C), 38.7 (N(CH3)2), 20.9 (mesityl CH3), 20.8 (mesityl CH3), 18.7 (CCCH3), 12.6 (CpCH3) ppm. IR (KBr, cm−1): ν 2908 (m), 1579 (s), 1431 (s), 1265 (s), 1182 (s), 993 (s), 808 (s). Anal. Calcd for C51H65N3Th: C, 64.33; H, 6.88; N, 4.41. Found: C, 64.35; H, 6.85; N, 4.42. Method B: NMR Scale. A C6D6 (0.3 mL) solution of PhCCMe (2.3 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 8 were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at 70 °C overnight. Preparation of (η 5 -C 5 Me 5 ) 2 Th[N(mesityl)C(C 2 SiMe 3 ) CHSiMe3](κ2-C,N-4-Me2NC5H3N) (9). Method A. This compound was obtained as colorless crystals from the reaction of (η5C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and Me3SiCCCCSiMe3 (42 mg, 0.20 mmol) in toluene (15 mL) at 70 °C and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 177 mg (93%). Mp: 158−160 °C dec. 1H NMR (C6D6): δ 6.91 (s, 2H, mesityl), 6.80

toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 159 mg (92%). Mp: 120−122 °C dec. 1H NMR (C6D6): δ 8.49 (d, J = 6.0 Hz, 2H, DMAP), 7.55 (m, 2H, phenyl), 7.11 (m, 3H, phenyl), 7.07 (s, 1H, mesityl), 6.63 (s, 1H, mesityl), 6.10 (d, J = 6.2 Hz, 2H, DMAP), 4.85 (s, 2H, SiH2), 2.37 (m, 8H, ThCH2 and mesityl CH3), 2.21 (s, 6H, N(CH3)2), 1.92 (s, 30H, Cp CH3) ppm. 13 C{1H} NMR (C6D6): δ 154.1 (aryl C), 150.6 (aryl C), 147.9 (aryl C), 142.1 (aryl C), 134.5 (aryl C), 134.3 (aryl C), 130.8 (aryl C), 130.7 (aryl C), 127.4 (aryl C), 126.2 (aryl C), 125.9 (aryl C), 124.2 (ring C), 106.9 (aryl C), 78.9 (ThCH2), 38.3 (N(CH3)2), 21.2 (mesityl CH3), 21.1 (mesityl CH3), 11.4 (CpCH3) ppm. IR (KBr, cm−1): ν 2906 (s), 2075 (m), 1614 (s), 1541 (s), 1442 (s), 1386 (s), 1228 (s), 1111 (s), 999 (s), 962 (s), 889 (s). Anal. Calcd for C42H57N3SiTh: C, 58.38; H, 6.65; N, 4.86. Found: C, 58.37; H, 6.53; N, 4.88. Method B: NMR Scale. A C6D6 (0.3 mL) solution of PhSiH3 (2.2 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 4 were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. Preparation of (η 5 -C 5 Me 5 ) 2 Th[κ-N-{NCPh(N(mesityl))}](DMAP)·3C6H6 (5·3C6H6). Method A. This compound was obtained as colorless crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and PhCN (21 mg, 0.20 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 188 mg (86%). Mp: 140−142 °C. 1H NMR (C6D6): δ 7.91 (s, 1H, DMAP), 7.36 (s, 2H, phenyl), 7.15 (s, 18H, C6H6), 6.91 (s, 3H, phenyl), 6.78 (s, 2H, mesityl), 6.59 (s, 1H, DMAP), 6.21 (s, 1H, DMAP), 6.05 (s, 1H, DMAP), 2.35 (s, 6H, mesityl CH3), 2.22 (s, 3H, mesityl CH3), 2.19 (s, 6H, N(CH3)2), 2.10 (s, 30H, Cp CH3) ppm. 13C{1H} NMR (C6D6): δ 174.2 (NC), 154.1 (aryl C), 146.9 (aryl C), 142.9 (aryl C), 140.5 (aryl C), 131.9 (aryl C), 130.7 (aryl C), 129.5 (aryl C), 129.1 (aryl C), 128.6 (C6H6), 127.5 (aryl C), 121.5 (ring C), 110.7 (aryl C), 107.2 (aryl C), 38.6 (N(CH3)2), 21.4 (mesityl CH3), 20.8 (mesityl CH3), 12.1 (CpCH3) ppm. IR (KBr, cm−1): ν 2908 (s), 2856 (s), 1637 (m), 1604 (m), 1579 (s), 1483 (s), 1433 (s), 1255 (s), 993 (s). Anal. Calcd for C61H74N4Th: C, 66.89; H, 6.81; N, 5.12. Found: C, 66.87; H, 6.85; N, 5.07. Method B: NMR Scale. A C6D6 (0.3 mL) solution of PhCN (2.1 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 5 were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. Preparation of (η5-C5Me5)2Th[N(mesityl)C(CHPh2)NH](N CCPh2) (6). Method A. This compound was obtained as yellow crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and Ph2CHCN (78 mg, 0.40 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 184 mg (90%). Mp: 200−202 °C dec. 1H NMR (C6D6): δ 7.34 (d, J = 7.7 Hz, 4H, phenyl), 7.21 (t, J = 7.3 Hz, 4H, phenyl), 7.14 (d, J = 8.4 Hz, 4H, phenyl), 7.03 (t, J = 7.4 Hz, 4H, phenyl), 6.96 (m, 4H, phenyl), 6.87 (s, 2H, mesityl), 6.02 (s, 1H, CHPh2), 4.83 (s, 1H, NH), 2.24 (s, 3H, mesityl CH3), 2.07 (s, 6H, mesityl CH3), 1.95 (s, 30H, Cp CH3) ppm. 13C{1H} NMR (C6D6): δ 176.6 (NCC), 162.2 (N CC), 142.4 (aryl C), 140.3 (aryl C), 139.7 (aryl C), 134.3 (aryl C), 132.7 (aryl C), 130.1 (aryl C), 129.5 (aryl C), 129.0 (aryl C), 128.7 (aryl C), 127.6 (aryl C), 126.3 (aryl C), 125.4 (ring C), 121.7 (aryl C), 56.3 (NCN), 55.6 (CHPh2), 20.9 (mesityl CH3), 20.5 (mesityl CH3), 11.8 (CpCH3) ppm. IR (KBr, cm−1): ν 3103 (m), 2040 (m), 1639 (s), 1400 (s), 1261 (s), 1028 (s), 784 (s). Anal. Calcd for C57H63N3Th: C, 66.98; H, 6.21; N, 4.11. Found: C, 67.04; H, 6.19; N, 4.13. Method B: NMR Scale. A C6D6 (0.3 mL) solution of Ph2CHCN (7.8 mg, 0.04 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 6 and those of DMAP were J


Article

Organometallics

crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and PhNCS (27 mg, 0.20 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 173 mg (89%). Mp: 158−160 °C dec. 1H NMR (C6D6): δ 8.42 (s, 2H, DMAP), 7.20 (m, 2H, phenyl), 7.15 (s, 6H, C6H6), 7.02 (m, 3H, phenyl), 6.71 (s, 2H, mesityl), 6.04 (s, 2H, DMAP), 2.20 (s, 6H, N(CH3)2), 2.11 (s, 30H, Cp CH3), 2.09 (s, 3H, mesityl CH3), 1.97 (s, 6H, mesityl CH3) ppm. 13C{1H} NMR (C6D6): δ 176.4 (CN), 150.5 (DMAP), 146.6 (DMAP), 137.2 (phenyl C), 137.0 (phenyl C), 129.6 (phenyl C), 129.1 (phenyl C), 128.8 (phenyl C), 128.6 (C6H6), 127.4 (phenyl C), 125.4 (phenyl C), 125.0 (phenyl C), 122.8 (ring C), 106.9 (DMAP), 38.2 (N(CH3)2), 21.0 (mesityl CH3), 18.9 (mesityl CH3), 11.8 (CpCH3) ppm. IR (KBr, cm−1): ν 2902 (s), 1600 (s), 1508 (s), 1375 (s), 1317 (s), 1294 (s), 1226 (s), 995 (s), 802 (s). Anal. Calcd for C49H62N4STh: C, 60.60; H, 6.43; N, 5.77. Found: C, 60.57; H, 6.44; N, 5.81. Method B: NMR Scale. A C6D6 (0.3 mL) solution of PhNCS (2.7 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 12 were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. Preparation of (η5-C5Me5)2Th[(μ-O)2(CPh2)](DMAP) (13). Method A. This compound was obtained as colorless crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and Ph2CO (73 mg, 0.40 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 125 mg (76%). Mp: 84−86 °C. 1H NMR (C6D6): δ 9.00 (br s, 2H, DMAP), 8.19 (d, J = 7.7 Hz, 4H, phenyl), 7.30 (t, J = 7.4 Hz, 4H, phenyl), 7.06 (t, J = 6.9 Hz, 2H, phenyl), 6.07 (d, J = 6.0 Hz, 2H, DMAP), 2.08 (s, 6H, N(CH3)2), 1.93 (s, 30H, Cp CH3). 13C{1H} NMR (C6D6): δ 156.3 (aryl C), 154.9 (aryl C), 149.7 (aryl C), 127.4 (aryl C), 127.0 (aryl C), 125.9 (aryl C), 123.5 (ring C), 106.7 (aryl C), 96.3 (CO), 38.3 (NCH3), 11.9 (CpCH3). IR (KBr, cm−1): ν 2904 (s), 2854 (s), 1614 (s), 1533 (s), 1446 (s), 1384 (s), 1276 (s), 1232 (s), 1022 (s), 1001 (s), 808 (s). Anal. Calcd for C40H50N2O2Th: C, 58.38; H, 6.12; N, 3.40. Found: C, 58.37; H, 6.14; N, 3.41. Method B: NMR Scale. A C6D6 (0.3 mL) solution of Ph2CO (7.3 mg, 0.04 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 13 and those of (mesityl)N CPh219 (1H NMR (C6D6): δ 7.94 (m, 2H, phenyl), 7.06 (m, 4H, phenyl), 6.85 (m, 4H, phenyl), 6.68 (s, 2H, phenyl), 2.11 (s, 6H, CH3), 2.08 (s, 3H, CH3) ppm) were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. Reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1) with Ph2CO: NMR Scale. A C6D6 (0.3 mL) solution of Ph2CO (3.7 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 13 along with those of unreacted 1 and (mesityl)NCPh2 were observed by 1H NMR spectroscopy (50% conversion based on 1) when this solution was kept at room temperature overnight. Preparation of (η5-C5Me5)2Th(NH-mesityl)(κ-O-1-OC9H7) (14). Method A. This compound was obtained as colorless crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and 1-indanone (27 mg, 0.20 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 132 mg (86%). Mp: 120−122 °C dec. 1H NMR (C6D6): δ 7.77 (d, J = 7.6 Hz, 1H, phenyl), 7.40 (t, J = 7.4 Hz, 1H, phenyl), 7.32 (m, 2H, phenyl), 6.90 (s, 2H, mesityl), 5.47 (t, J = 2.4 Hz, 1H, CCH), 4.44 (s, 1H, NH), 3.26 (d, J = 2.3 Hz, 2H, CH2), 2.44 (s, 6H, mesityl CH3), 2.33 (s, 3H, mesityl CH3), 1.99 (s, 30H, Cp CH3) ppm. 13C{1H} NMR (C6D6): δ 162.3 (phenyl C), 143.8 (phenyl C), 143.5 (phenyl C), 129.3 (phenyl C), 126.1 (phenyl C), 125.4 (ring C), 125.2 (phenyl C), 124.5 (phenyl C), 124.3 (phenyl C), 122.9 (phenyl C), 122.8 (phenyl

(s, 1H, DMAP), 5.88 (dd, J = 6.2 and 2.6 Hz, 1H, DMAP), 4.92 (s, 1H, CCH), 2.38 (s, 3H, mesityl CH3), 2.29 (s, 6H, N(CH3)2), 2.27 (s, 6H, mesityl CH3), 2.15 (s, 30H, Cp CH3), 0.70 (s, 9H, Si(CH3)3), 0.01 (s, 9H, Si(CH3)3) ppm; one proton of DMAP was not observed. 13 C{1H} NMR (C6D6): δ 230.0 (Th C), 154.7 (aryl C), 152.1 (aryl C), 150.2 (aryl C), 143.6 (aryl C), 135.6 (aryl C), 131.3 (aryl C), 128.5 (aryl C), 124.2 (ring C), 108.6 (CC), 108.0 (py), 106.9 (CC), 97.0 (CC), 95.2 (CC), 38.7 (N(CH3)2), 21.1 (mesityl CH3), 20.9 (mesityl CH3), 12.5 (CpCH3), 1.0 (Si(CH3)3), −0.5 (Si(CH3)3) ppm. IR (KBr, cm−1): ν 2914 (s), 2070 (m), 1577 (s), 1498 (s), 1429 (s), 1242 (s), 1122 (s), 991 (s), 931 (s), 833 (s). Anal. Calcd for C46H69N3Si2Th: C, 58.02; H, 7.30; N, 4.41. Found: C, 57.98; H, 7.31; N, 4.38. Method B: NMR Scale. A C6D6 (0.3 mL) solution of Me3SiC CCCSiMe3 (4.2 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 9 were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at 70 °C overnight. Preparation of (η5-C5Me 5) 2Th[N(mesityl)C(NiPr)-NiPr](DMAP) (10). Method A. This compound was obtained as colorless crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and (iPrN)2C (25 mg, 0.20 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 164 mg (93%). Mp: 144−146 °C dec. 1H NMR (C6D6): δ 8.03 (s, 2H, DMAP), 6.85 (s, 2H, mesityl), 5.99 (d, J = 5.4 Hz, 2H, DMAP), 4.87 (m, 1H, CH(CH3)2), 3.51 (m, 1H, CH(CH3)2), 2.43 (s, 6H, mesityl CH3), 2.33 (s, 3H, mesityl CH3), 2.11 (s, 6H, N(CH3)2), 2.04 (s, 30H, Cp CH3), 1.79 (d, J = 4.3 Hz, 6H, CH(CH3)2), 1.22 (m, 6H, CH(CH3)2) ppm. 13C{1H} NMR (C6D6): δ 154.2 (DMAP), 150.2 (DMAP), 147.6 (CN), 130.3 (phenyl C), 128.7 (phenyl C), 126.0 (ring C), 122.5 (phenyl C), 121.8 (phenyl C), 106.3 (DMAP), 46.7 (CH(CH3)2), 46.2 (CH(CH3)2), 38.2 (N(CH3)2), 26.1 (CH(CH3)2), 23.5 (CH(CH3)2), 21.0 (mesityl CH3), 18.7 (mesityl CH3), 12.3 (CpCH3) ppm. IR (KBr, cm−1): ν 2966 (s), 1637 (s), 1604 (s), 1508 (s), 1475 (s), 1382 (s), 1176 (s), 1124 (s), 852 (s). Anal. Calcd for C43H65N5Th: C, 58.42; H, 7.41; N, 7.92. Found: C, 58.40; H, 7.38; N, 7.94. Method B: NMR Scale. A C6D6 (0.3 mL) solution of (iPrN)2C (2.5 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 10 were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. Preparation of (η5-C5Me5)2Th[SCN(mesityl)-S](DMAP) (11). Method A. This compound was obtained as yellow crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and CS2 (16 mg, 0.20 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 152 mg (91%). Mp: 150−152 °C dec. 1H NMR (C6D6): δ 8.06 (d, J = 6.6 Hz, 2H, DMAP), 7.02 (s, 2H, mesityl), 5.64 (d, J = 4.9 Hz, 2H, DMAP), 2.71 (s, 3H, mesityl CH3), 2.66 (s, 6H, mesityl CH3), 2.32 (s, 6H, N(CH3)2), 2.05 (s, 30H, Cp CH3) ppm. 13C{1H} NMR (C6D6): δ 170.1 (CN), 154.7 (DMAP), 150.7 (DMAP), 135.0 (phenyl C), 128.9 (phenyl C), 128.8 (phenyl C), 127.4 (phenyl C), 125.5 (ring C), 106.8 (DMAP), 38.3 (N(CH3)2), 19.4 (mesityl CH3), 18.3 (mesityl CH3), 12.3 (CpCH3) ppm. IR (KBr, cm−1): ν 3132 (s), 3024 (s), 1610 (s), 1400 (s), 1228 (s), 997 (s), 804 (s). Anal. Calcd for C37H51N3S2Th: C, 53.29; H, 6.16; N, 5.04. Found: C, 53.31; H, 6.15; N, 5.00. Method B: NMR Scale. A C6D6 (0.3 mL) solution of CS2 (1.6 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 11 were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. Preparation of (η5-C5Me5)2Th[SCN(mesityl)-NPh](DMAP)· C6H6 (12·C6H6). Method A. This compound was obtained as colorless K


Article

Organometallics

cm−1): ν 2962 (s), 2903 (s), 2145 (m), 2080 (m), 2030 (m), 1605 (m), 1441 (s), 1384 (s), 1260 (s), 1091 (s), 1019 (s), 919 (s), 799 (s). Anal. Calcd for C48H78N6Si2Th2: C, 45.78; H, 6.24; N, 6.67. Found: C, 45.76; H, 6.25; N, 6.65. Method B: NMR Scale. A C6D6 (0.3 mL) solution of Me3SiCHN2 (2.3 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 17 and those of DMAP and mesitylene (1H NMR (C6D6): δ 6.92 (s, 3H, phenyl), 2.27 (s, 9H, CH3) ppm) were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. X-ray Crystallography. Single-crystal X-ray diffraction measurements were performed out on a Bruker Smart APEX II CCD diffractometer at 100(2) K using graphite-monochromated Mο Kα radiation (λ = 0.71073 Å). An empirical absorption correction was applied using the SADABS program.21 All structures were solved by direct methods and refined by full-matrix least squares on F2 using the SHELXL program package.22 All hydrogen atoms were included in geometrically fixed positions using a riding model. The crystal and experimental data for 2−15 and 17 are summarized in the Supporting Information. Selected bond lengths and angles are given in Table 1.

C), 121.5 (CC), 119.0 (CC), 33.6 (CH2), 20.8 (mesityl CH3), 17.6 (mesityl CH3), 11.4 (CpCH3) ppm. IR (KBr, cm−1): ν 3178 (w), 2907 (s), 1613 (s), 1568 (s), 1442 (s), 1368 (s), 1230 (s), 1001 (s), 806 (s). Anal. Calcd for C38H49NOTh: C, 59.44; H, 6.43; N, 1.82. Found: C, 59.42; H, 6.45; N, 1.80. Method B: NMR Scale. A C6D6 (0.3 mL) solution of 1-indanone (2.6 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 14 and those of DMAP were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. Preparation of (η5-C5Me5)2Th[OCH(Me)C(O)OCH(Me)C( N-mesityl)O] (15). Method A. This compound was obtained as colorless crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and rac-lactide (29 mg, 0.20 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 136 mg (87%). Mp: 250−252 °C dec. 1H NMR (C6D6): δ 6.98 (s, 2H, mesityl), 5.77 (q, J = 6.5 Hz, 1H, CH), 4.92 (q, J = 6.9 Hz, 1H, CH), 2.47 (s, 6H, mesityl CH3), 2.29 (s, 3H, mesityl CH3), 1.91 (s, 15H, Cp CH3), 1.88 (d, J = 6.5 Hz, 3H, CH3), 1.82 (s, 15H, Cp CH3), 1.31 (d, J = 7.0 Hz, 3H, CH3) ppm. 13C{1H} NMR (C6D6): δ 175.1 (CO), 161.9 (CN), 144.2 (phenyl C), 131.0 (phenyl C), 128.9 (phenyl C), 128.6 (phenyl C), 125.0 (ring C), 124.6 (ring C), 80.6 (OC), 73.5 (OC), 23.8 (mesityl CH3), 21.1 (mesityl CH3), 20.6 (CH3), 19.9 (CH3), 11.4 (CpCH3), 10.9 (CpCH3) ppm. IR (KBr, cm−1): ν 2908 (s), 1778 (s), 1631 (s), 1438 (s), 1321 (s), 1265 (s), 1182 (s), 1016 (s), 854 (s). Anal. Calcd for C35H49NO4Th: C, 53.91; H, 6.33; N, 1.80. Found: C, 53.90; H, 6.30; N, 1.82. Method B: NMR Scale. A C6D6 (0.3 mL) solution of rac-lactide (2.9 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 15 and those of DMAP were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. Preparation of (η5-C5Me5)2Th[N(p-tolyl)NNN(p-tolyl)] (16). Method A. This compound was obtained as orange microcrystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and (p-tolyl)N3 (54 mg, 0.40 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 116 mg (78%). 1H NMR (C6D6): δ 7.12 (d, J = 7.2 Hz, 4H, phenyl), 7.04 (d, J = 7.2 Hz, 4H, phenyl), 2.25 (s, 6H, tolyl CH3), 1.88 (s, 30H, Cp CH3) ppm. These spectroscopic data agreed with those reported in the literature.15 Method B: NMR Scale. A C6D6 (0.3 mL) solution of (p-tolyl)N3 (5.3 mg, 0.04 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.2 mL). Resonances of 16 and those of DMAP and (mesityl)N320 (1H NMR (C6D6): δ 6.54 (s, 2H, phenyl), 2.11 (s, 6H, CH3), 2.01 (s, 3H, CH3) ppm) were observed by 1H NMR spectroscopy (100% conversion) when this solution was kept at room temperature overnight. Reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1) with ptolyl-N3: NMR Scale. A C6D6 (0.2 mL) solution of (p-tolyl)N3 (2.7 mg, 0.02 mmol) was slowly added to a J. Young NMR tube charged with (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 15 mg, 0.02 mmol) and C6D6 (0.3 mL). Resonances of 16 along with those of unreacted 1 and DMAP and (mesityl)N3 were observed by 1H NMR spectroscopy (50% conversion based on 1) when this solution was kept at room temperature overnight. Preparation of [(η5-C5Me5)2Th]2(μ-NNNCSiMe3)2 (17). Method A. This compound was obtained as yellow crystals from the reaction of (η5-C5Me5)2ThN(mesityl)(DMAP) (1; 152 mg, 0.20 mmol) and Me3SiCHN2 (23 mg, 0.20 mmol) in toluene (15 mL) at room temperature and recrystallization from a benzene solution by a procedure similar to that described in the synthesis of 2. Yield: 88 mg (70%). Mp: 114−116 °C dec. 1H NMR (C6D6): δ 2.13 (s, 60H, Cp CH3), 0.52 (s, 18H, SiCH3) ppm. 13C{1H} NMR (C6D6): δ 129.3 (CN), 124.4 (ring C), 11.7 (CpCH3), 3.1 (SiCH3) ppm. IR (KBr,

■

ASSOCIATED CONTENT

* Supporting Information S

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.organomet.7b00212. Crystal parameters for compounds 2−15 and 17 (PDF) Accession Codes

CCDC 1546136−1546150 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by emailing [email protected], or by contacting The Cambridge Crystallographic Data Centre, 12, Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033.

■

AUTHOR INFORMATION

Corresponding Authors

*E-mail for G.Z.: [email protected]. *E-mail for M.D.W.: [email protected]. ORCID

Guofu Zi: 0000-0002-7455-460X Marc D. Walter: 0000-0002-4682-8749 Author Contributions §

C.Z. and P.Y. contributed equally to this work.

Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS Dedicated to Prof. Richard A. Andersen on the occasion of his 75th birthday. This work was supported by the National Natural Science Foundation of China (Grant No. 21472013), and the Deutsche Forschungsgemeinschaft (DFG) through the Heisenberg program (WA 2513/6).

■

REFERENCES

(1) For selected recent reviews, see: (a) Ephritikhine, M. Dalton Trans. 2006, 2501−2516. (b) Barnea, E.; Eisen, M. S. Coord. Chem. Rev. 2006, 250, 855−899. (c) Zi, G.-F.; Zhang, Z.-B.; Xiang, L.; Wang, Q.-W. Chin. J. Org. Chem. 2006, 26, 1606−1611. (d) Fox, A. R.; Bart, S. C.; Meyer, K.; Cummins, C. C. Nature 2008, 455, 341−349. (e) Andrea, T.; Eisen, M. S. Chem. Soc. Rev. 2008, 37, 550−567. (f) Graves, C. R.; Kiplinger, J. L. Chem. Commun. 2009, 3831−3853. L


Article

Organometallics (g) Hayton, T. W. Dalton Trans. 2010, 39, 1145−1158. (h) Arnold, P. L. Chem. Commun. 2011, 47, 9005−9010. (i) Hayton, T. W. Chem. Commun. 2013, 49, 2956−2973. (j) Hayton, T. W. Nat. Chem. 2013, 5, 451−452. (k) Ren, W.; Zhao, N.; Chen, L.; Zi, G. Chin. J. Org. Chem. 2013, 33, 1121−1136. (l) Zi, G. Sci. China: Chem. 2014, 57, 1064−1072. (m) La Pierre, H. S.; Meyer, K. Prog. Inorg. Chem. 2014, 58, 303−415. (2) For selected papers on actinide nonmetallocenes containing terminal imido groups, see: (a) Burns, C. J.; Smith, W. H.; Huffman, J. C.; Sattelberger, A. P. J. Am. Chem. Soc. 1990, 112, 3237−3239. (b) Brown, D. R.; Denning, R. G. Inorg. Chem. 1996, 35, 6158−6163. (c) Roussel, P.; Boaretto, R.; Kingsley, A. J.; Alcock, N. W.; Scott, P. J. Chem. Soc., Dalton Trans. 2002, 1423−1428. (d) Castro-Rodriguez, I.; Olsen, K.; Gantzel, P.; Meyer, K. J. Am. Chem. Soc. 2003, 125, 4565− 4571. (e) Hayton, T. W.; Boncella, J. M.; Scott, B. L.; Palmer, P. D.; Batista, E. R.; Hay, P. J. Science 2005, 310, 1941−1943. (f) Hayton, T. W.; Boncella, J. M.; Scott, B. L.; Batista, E. R.; Hay, P. J. J. Am. Chem. Soc. 2006, 128, 10549−10559. (g) Hayton, T. W.; Boncella, J. M.; Scott, B. L.; Batista, E. R. J. Am. Chem. Soc. 2006, 128, 12622−12623. (h) Castro-Rodriguez, I.; Nakai, H.; Meyer, K. Angew. Chem., Int. Ed. 2006, 45, 2389−2392. (i) Spencer, L. P.; Yang, P.; Scott, B. L.; Batista, E. R.; Boncella, J. M. J. Am. Chem. Soc. 2008, 130, 2930−2931. (j) Bart, S. C.; Anthon, C.; Heinemann, F. W.; Bill, E.; Edelstein, N. M.; Meyer, K. J. Am. Chem. Soc. 2008, 130, 12536−12546. (k) Spencer, L. P.; Schelter, E. J.; Yang, P.; Gdula, R. L.; Scott, B. L.; Thompson, J. D.; Kiplinger, J. L.; Batista, E. R.; Boncella, J. M. Angew. Chem., Int. Ed. 2009, 48, 3795−3798. (l) Spencer, L. P.; Yang, P.; Scott, B. L.; Batista, E. R.; Boncella, J. M. Inorg. Chem. 2009, 48, 2693−2700. (m) Spencer, L. P.; Yang, P.; Scott, B. L.; Batista, E. R.; Boncella, J. M. Inorg. Chem. 2009, 48, 11615−11623. (n) Swartz, D. L., II; Spencer, L. P.; Scott, B. L.; Odom, A. L.; Boncella, J. M. Dalton Trans. 2010, 39, 6841−6846. (o) Seaman, L. A.; Fortier, S.; Wu, G.; Hayton, T. W. Inorg. Chem. 2011, 50, 636−646. (p) Jilek, R. E.; Spencer, L. P.; Kuiper, D. L.; Scott, B. L.; Williams, U. J.; Kikkawa, J. M.; Schelter, E. J.; Boncella, J. M. Inorg. Chem. 2011, 50, 4235−4237. (q) Matson, E. M.; Fanwick, P. E.; Bart, S. C. Eur. J. Inorg. Chem. 2012, 2012, 5471−5478. (r) Matson, E. M.; Crestani, M. G.; Fanwick, P. E.; Bart, S. C. Dalton Trans. 2012, 41, 7952−7958. (s) Lam, O. P.; Franke, S. M.; Nakai, H.; Heinemann, F. W.; Hieringer, W.; Meyer, K. Inorg. Chem. 2012, 51, 6190−6199. (t) Camp, C.; Pécaut, J.; Mazzanti, M. J. Am. Chem. Soc. 2013, 135, 12101−12111. (u) King, D. M.; Tuna, F.; McInnes, E. J. L.; McMaster, J.; Lewis, W.; Blake, A. J.; Liddle, S. T. Science 2012, 337, 717−720. (v) King, D. M.; Tuna, F.; McInnes, E. J. L.; McMaster, J.; Lewis, W.; Blake, A. J.; Liddle, S. T. Nat. Chem. 2013, 5, 482−488. (w) King, D. M.; McMaster, J.; Tuna, F.; McInnes, E. J. L.; Lewis, W.; Blake, A. J.; Liddle, S. T. J. Am. Chem. Soc. 2014, 136, 5619−5622. (x) Tatebe, C. J.; Zeller, M.; Bart, S. C. Inorg. Chem. 2017, 56, 1956−1965. (3) For selected papers on actinide metallocenes containing terminal imido groups, see: (a) Cramer, R. E.; Panchanatheswaran, K.; Gilje, J. W. J. Am. Chem. Soc. 1984, 106, 1853−1854. (b) Brennan, J. G.; Andersen, R. A. J. Am. Chem. Soc. 1985, 107, 514−516. (c) Rosen, R. K.; Andersen, R. A.; Edelstein, N. M. J. Am. Chem. Soc. 1990, 112, 4588−4590. (d) Arney, D. S. J.; Burns, C. J.; Smith, D. C. J. Am. Chem. Soc. 1992, 114, 10068−10069. (e) Arney, D. S. J.; Burns, C. J. J. Am. Chem. Soc. 1993, 115, 9840−9841. (f) Arney, D. S. J.; Burns, C. J. J. Am. Chem. Soc. 1995, 117, 9448−9460. (g) Straub, T.; Frank, W.; Reiss, G. J.; Eisen, M. S. J. Chem. Soc., Dalton Trans. 1996, 2541−2546. (h) Warner, B. P.; Scott, B. L.; Burns, C. J. Angew. Chem., Int. Ed. 1998, 37, 959−960. (i) Peters, R. G.; Warner, B. P.; Scott, B. L.; Burns, C. J. Organometallics 1999, 18, 2587−2589. (j) Straub, T.; Haskel, A.; Neyroud, T. G.; Kapon, M.; Botoshansky, M.; Eisen, M. S. Organometallics 2001, 20, 5017−5035. (k) Kiplinger, J. L.; Morris, D. E.; Scott, B. L.; Burns, C. J. Chem. Commun. 2002, 30−31. (l) Evans, W. J.; Kozimor, S. A.; Ziller, J. W. Chem. Commun. 2005, 4681−4683. (m) Zi, G.; Jia, L.; Werkema, E. L.; Walter, M. D.; Gottfriedsen, J. P.; Andersen, R. A. Organometallics 2005, 24, 4251− 4262. (n) Zi, G.; Blosch, L. L.; Jia, L.; Andersen, R. A. Organometallics 2005, 24, 4602−4612. (o) Graves, C. R.; Scott, B. L.; Morris, D. E.; Kiplinger, J. L. J. Am. Chem. Soc. 2007, 129, 11914−11915. (p) Graves,

C. R.; Yang, P.; Kozimor, S. A.; Vaughn, A. E.; Clark, D. L.; Conradson, S. D.; Schelter, E. J.; Scott, B. L.; Thompson, J. D.; Hay, P. J.; Morris, D. E.; Kiplinger, J. L. J. Am. Chem. Soc. 2008, 130, 5272− 5285. (q) Graves, C. R.; Scott, B. L.; Morris, D. E.; Kiplinger, J. L. Organometallics 2008, 27, 3335−3337. (r) Graves, C. R.; Vaughn, A. E.; Schelter, E. J.; Scott, B. L.; Thompson, J. D.; Morris, D. E.; Kiplinger, J. L. Inorg. Chem. 2008, 47, 11879−11891. (s) Spencer, L. P.; Gdula, R. L.; Hayton, T. W.; Scott, B. L.; Boncella, J. M. Chem. Commun. 2008, 4986−4988. (t) Evans, W. J.; Traina, C. A.; Ziller, J. W. J. Am. Chem. Soc. 2009, 131, 17473−17481. (u) Graves, C. R.; Scott, B. L.; Morris, D. E.; Kiplinger, J. L. Chem. Commun. 2009, 776− 778. (v) Evans, W. J.; Montalvo, E.; Ziller, J. W.; DiPasquale, A. G.; Rheingold, A. L. Inorg. Chem. 2010, 49, 222−228. (w) Thomson, R. K.; Cantat, T.; Scott, B. L.; Morris, D. E.; Batista, E. R.; Kiplinger, J. L. Nat. Chem. 2010, 2, 723−729. (x) Zhang, L.; Zhang, C.; Hou, G.; Zi, G.; Walter, M. D. Organometallics 2017, 36, 1179−1187. (4) (a) Haskel, A.; Straub, T.; Eisen, M. S. Organometallics 1996, 15, 3773−3775. (b) Korobkov, I.; Gambarotta, S.; Yap, G. P. A. Angew. Chem., Int. Ed. 2003, 42, 814−818. (c) Schelter, E. J.; Morris, D. E.; Scott, B. L.; Kiplinger, J. L. Chem. Commun. 2007, 1029−1031. (d) Bell, N. L.; Maron, L.; Arnold, P. L. J. Am. Chem. Soc. 2015, 137, 10492−10495. (5) For selected papers on scandium imido complexes, see: (a) Scott, J.; Basuli, F.; Fout, A. R.; Huffman, J. C.; Mindiola, D. J. Angew. Chem., Int. Ed. 2008, 47, 8502−8505. (b) Lu, E.; Li, Y.; Chen, Y. Chem. Commun. 2010, 46, 4469−4471. (c) Lu, E.; Chu, J.; Borzov, M.; Chen, Y.; Li, G. Chem. Commun. 2011, 47, 743−745. (d) Chu, J.; Lu, E.; Liu, Z.; Chen, Y.; Leng, X.; Song, H. Angew. Chem., Int. Ed. 2011, 50, 7677−7680. (e) Lu, E.; Zhou, Q.; Li, Y.; Chu, J.; Chen, Y.; Leng, X.; Sun, J. Chem. Commun. 2012, 48, 3403−3405. (f) Jian, Z.; Rong, W.; Mou, Z.; Pan, Y.; Xie, H.; Cui, D. Chem. Commun. 2012, 48, 7516− 7518. (g) Wicker, B. F.; Fan, H.; Hickey, A. K.; Crestani, M. G.; Scott, J.; Pink, M.; Mindiola, D. J. J. Am. Chem. Soc. 2012, 134, 20081− 20096. (h) Chu, T.; Piers, W. E.; Dutton, J. L.; Parvez, M. Organometallics 2013, 32, 1159−1165. (i) Chu, J.; Lu, E.; Chen, Y.; Leng, X. Organometallics 2013, 32, 1137−1140. (j) Rong, W.; Cheng, J.; Mou, Z.; Xie, H.; Cui, D. Organometallics 2013, 32, 5523−5529. (k) Chu, J.; Kefalidis, C. E.; Maron, L.; Leng, X.; Chen, Y. J. Am. Chem. Soc. 2013, 135, 8165−8168. (l) Chu, J.; Han, X.; Kefalidis, C. E.; Zhou, J.; Maron, L.; Leng, X.; Chen, Y. J. Am. Chem. Soc. 2014, 136, 10894− 10897. (6) For selected papers on group 4 imido complexes, see: (a) Walsh, P. J.; Hollander, F. J.; Bergman, R. G. J. Am. Chem. Soc. 1988, 110, 8729−8731. (b) Cummins, C. C.; Baxter, S. M.; Wolczanski, P. T. J. Am. Chem. Soc. 1988, 110, 8731−8733. (c) Hill, J. E.; Profilet, R. D.; Fanwick, P. E.; Rothwell, I. P. Angew. Chem., Int. Ed. Engl. 1990, 29, 664−665. (d) Roesky, H. W.; Voelker, H.; Witt, M.; Noltemeyer, M. Angew. Chem., Int. Ed. Engl. 1990, 29, 669−670. (e) Walsh, P. J.; Hollander, F. J.; Bergman, R. G. Organometallics 1993, 12, 3705−3723. (f) Dunn, S. C.; Batsanov, A. S.; Mountford, P. J. Chem. Soc., Chem. Commun. 1994, 2007−2008. (g) Bennett, J. L.; Wolczanski, P. T. J. Am. Chem. Soc. 1994, 116, 2179−2180. (h) Meyer, K. E.; Walsh, P. J.; Bergman, R. G. J. Am. Chem. Soc. 1995, 117, 974−985. (i) Polse, J. L.; Andersen, R. A.; Bergman, R. G. J. Am. Chem. Soc. 1998, 120, 13405− 13414. (j) Hoyt, H. M.; Michael, F. E.; Bergman, R. G. J. Am. Chem. Soc. 2004, 126, 1018−1019. (k) Lian, B.; Spaniol, T. P.; HorrilloMartínez, P.; Hultzsch, K. C.; Okuda, J. Eur. J. Inorg. Chem. 2009, 2009, 429−434. (l) Tiong, P. J.; Nova, A.; Clot, E.; Mountford, P. Chem. Commun. 2011, 47, 3147−3149. (m) Tiong, P. J.; Nova, A.; Schwarz, A. D.; Selby, J. D.; Clot, E.; Mountford, P. Dalton Trans. 2012, 41, 2277−2288. (n) Schwarz, A. D.; Nielson, A. J.; Kaltsoyannis, N.; Mountford, P. Chem. Sci. 2012, 3, 819−824. (7) For selected recent papers on the bonding of organoactinide complexes, see: (a) Barros, N.; Maynau, D.; Maron, L.; Eisenstein, O.; Zi, G.; Andersen, R. A. Organometallics 2007, 26, 5059−5065. (b) Cantat, T.; Graves, C. R.; Jantunen, K. C.; Burns, C. J.; Scott, B. L.; Schelter, E. J.; Morris, D. E.; Hay, P. J.; Kiplinger, J. L. J. Am. Chem. Soc. 2008, 130, 17537−17551. (c) Yahia, A.; Maron, L. Organometallics 2009, 28, 672−679. (d) Walensky, J. R.; Martin, R. L.; M


Article

Organometallics Ziller, J. W.; Evans, W. J. Inorg. Chem. 2010, 49, 10007−10012. (e) Ren, W.; Deng, X.; Zi, G.; Fang, D.-C. Dalton Trans. 2011, 40, 9662−9664. (f) Seaman, L. A.; Pedrick, E. A.; Tsuchiya, T.; Wu, G.; Jakubikova, E.; Hayton, T. W. Angew. Chem., Int. Ed. 2013, 52, 10589− 10592. (g) Kaltsoyannis, N. Inorg. Chem. 2013, 52, 3407−3413. (h) Neidig, M. L.; Clark, D. L.; Martin, R. L. Coord. Chem. Rev. 2013, 257, 394−406. (i) Gardner, B. M.; Cleaves, P. A.; Kefalidis, C. E.; Fang, J.; Maron, L.; Lewis, W.; Blake, A. J.; Liddle, S. T. Chem. Sci. 2014, 5, 2489−2497. (j) Fang, B.; Ren, W.; Hou, G.; Zi, G.; Fang, D.C.; Maron, L.; Walter, M. D. J. Am. Chem. Soc. 2014, 136, 17249− 17261. (k) Fang, B.; Hou, G.; Zi, G.; Fang, D.-C.; Walter, M. D. Dalton Trans. 2015, 44, 7927−7934. (l) Fang, B.; Zhang, L.; Hou, G.; Zi, G.; Fang, D.-C.; Walter, M. D. Organometallics 2015, 34, 5669− 5681. (m) Bell, N. L.; Maron, L.; Arnold, L. L. J. Am. Chem. Soc. 2015, 137, 10492−10495. (n) Zhang, L.; Hou, G.; Zi, G.; Ding, W.; Walter, M. D. J. Am. Chem. Soc. 2016, 138, 5130−5142. (o) Smiles, D. E.; Wu, G.; Hrobárik, P.; Hayton, T. W. J. Am. Chem. Soc. 2016, 138, 814−825. (p) Browne, K. P.; Maerzke, K. A.; Travia, N. E.; Morris, D. E.; Scott, B. L.; Henson, N. J.; Yang, P.; Kiplinger, J. L.; Veauthier, J. M. Inorg. Chem. 2016, 55, 4941−4950. (q) Zhang, L.; Fang, B.; Hou, G.; Zi, G.; Ding, W.; Walter, M. D. Organometallics 2017, 36, 898−910. (8) (a) Ren, W.; Zi, G.; Fang, D.-C.; Walter, M. D. J. Am. Chem. Soc. 2011, 133, 13183−13196. (b) Ren, W.; Zi, G.; Fang, D.-C.; Walter, M. D. Chem. - Eur. J. 2011, 17, 12669−12682. (c) Ren, W.; Zi, G.; Walter, M. D. Organometallics 2012, 31, 672−679. (d) Ren, W.; Zhou, E.; Fang, B.; Zi, G.; Fang, D.-C.; Walter, M. D. Chem. Sci. 2014, 5, 3165− 3172. (e) Ren, W.; Zhou, E.; Fang, B.; Hou, G.; Zi, G.; Fang, D.-C.; Walter, M. D. Angew. Chem., Int. Ed. 2014, 53, 11310−11314. (f) Zhou, E.; Ren, W.; Hou, G.; Zi, G.; Fang, D.-C.; Walter, M. D. Organometallics 2015, 34, 3637−3647. (9) Yang, P.; Zhou, E.; Hou, G.; Zi, G.; Ding, W.; Walter, M. D. Chem. - Eur. J. 2016, 22, 13845−13849. (10) Nugent, W. A.; Mayer, J. M. Metal-Ligand Multiple Bonds; Wiley: New York, 1988. (11) (a) Jantunen, K. C.; Burns, C. J.; Castro-Rodriguez, I.; Da Re, R. E.; Golden, J. T.; Morris, D. E.; Scott, B. L.; Taw, F. L.; Kiplinger, J. L. Organometallics 2004, 23, 4682−4692. (b) Ren, W.; Zhao, N.; Chen, L.; Zi, G. Inorg. Chem. Commun. 2013, 30, 26−28. (12) Fang, B.; Zhang, L.; Hou, G.; Zi, G.; Fang, D.-C.; Walter, M. D. Organometallics 2015, 34, 5669−5681. (13) (a) Karmel, I. S. R.; Fridman, N.; Tamm, M.; Eisen, M. S. J. Am. Chem. Soc. 2014, 136, 17180−17192. (b) Karmel, I. S. R.; Fridman, N.; Tamm, M.; Eisen, M. S. Organometallics 2015, 34, 2933−2942. (c) Ghatak, T.; Fridman, N.; Eisen, M. S. Organometallics 2017, 36, 1296−1302. (14) (a) Garner, M. E.; Hohloch, S.; Maron, L.; Arnold, J. Angew. Chem., Int. Ed. 2016, 55, 13789−13792. (b) Hervé, A.; Thuéry, P.; Ephritikhine, M.; Berthet, J.-C. Organometallics 2014, 33, 2088−2098. (15) Yang, P.; Zhou, E.; Fang, B.; Hou, G.; Zi, G.; Walter, M. D. Organometallics 2016, 35, 2129−2139. (16) (a) Korobkov, I.; Arunachalampillai, A.; Gambarotta, S. Organometallics 2004, 23, 6248−6252. (b) Korobkov, I.; Vidjayacoumar, B.; Gorelsky, S. I.; Billone, P.; Gambarotta, S. Organometallics 2010, 29, 692−702. (c) Fang, B.; Zhang, L.; Hou, G.; Zi, G.; Fang, D.-C.; Walter, M. D. Chem. Sci. 2015, 6, 4897−4906. (d) Fang, B.; Hou, G.; Zi, G.; Ding, W.; Walter, M. D. Organometallics 2016, 35, 1384−1391. (17) Ugi, I.; Perlinger, H.; Behringer, L. Chem. Ber. 1958, 91, 2330− 2336. (18) Schulz, F.; Sumerin, V.; Leskelä, M.; Repo, T.; Rieger, B. Dalton Trans. 2010, 39, 1920−1922. (19) Harrold, N. D.; Waterman, R.; Hillhouse, G. L.; Cundari, T. R. J. Am. Chem. Soc. 2009, 131, 12872−12873. (20) Hubbard, A.; Okazaki, T.; Laali, K. K. J. Org. Chem. 2008, 73, 316−319. (21) Sheldrick, G. M. SADABS, Program for Empirical Absorption Correction of Area Detector Data; University of Göttingen, Göttingen, Germany, 1996.

(22) Sheldrick, G. M. Acta Crystallogr., Sect. A: Found. Crystallogr. 2008, 64, 112−122.

N


Reactivity of a Lewis Base Supported Thorium Terminal Imido

Recommend Documents