Selective meta-CâH Bond Activation of Substituted 1,3

Article pubs.acs.org/Organometallics

Selective meta-C−H Bond Activation of Substituted 1,3Chlorobenzenes Promoted by an Osmium Pyridyl Complex Sonia Bajo, Miguel A. Esteruelas,* Ana M. López, and Enrique Oñate Departamento de Quı ́mica Inorgánica, Instituto de Sı ́ntesis Quı ́mica y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain S Supporting Information *

ABSTRACT: Ethylene displaces both the acetone and phosphine ligands of [OsTp{κ1C-HNC5H3Me}(κ1-OCMe2)(PiPr3)]BF4 (2; Tp = hydrydotris(pyrazolyl)borate). The reaction takes place by stages. Initially the replacement of acetone gives the mono(olefin) derivative [OsTp{κ1-C[HNC5H3Me]}(η2-CH2CH2)(PiPr3)]BF4 (3). The substitution of the phosphine occurs at 120 °C and leads to the bis(olefin) complex [OsTp{κ1-C[HNC5H3Me]}(η2-CH2 CH2)2]BF4 (4). The NH wingtip of 3 and 4 undergoes deprotonation with tert-butoxide to afford the corresponding pyridyl compounds [OsTp{κ1-C[NC5H3Me]}(η2-CH2 CH2)(PiPr3)] (5) and [OsTp{κ1-C[NC5H3Me]}(η2-CH2CH2)2] (6). At 60 °C, the solvents chloro-3-fluorobenzene, 1,3dichlorobenzene, and 3-chlorotoluene displace the pyridyl ligand of 6 to yield the haloaryl derivatives [OsTp(3,5-C6H3ClX)(η2CH2CH2)2] (X = F (7), Cl (8), Me (9)) as a result of the selective meta-C−H bond activation of the haloarenes.

■

INTRODUCTION The activation of the C−H bonds by transition-metal complexes1 is an extremely important process because of its connection with the functionalization of nonactivated organic molecules.2 The mechanisms proposed for these reactions can be put into three groups:1,3 homolytic cleavage, heterolytic cleavage, and σ-bond metathesis. The homolytic cleavage involves the oxidative addition of the C−H bond to the metal center. A lower energy transition state in C−H oxidative addition and lower energy products in C−halogen oxidative addition support the conclusion that C−H activation is more competitive in a kinetic sense, whereas C−halogen activation is more thermodynamically favored, in haloarenes.4 The kinetically controlled products are particularly preferred for aryl fluorides,5 which rarely undergo C−F cleavage.6 C−Cl, C−Br, and C−I oxidative additions are most common with zerovalent group 10 metal complexes, especially palladium7 and rhodium(I) derivatives.8 Electrophilic metal centers prevent homolytic cleavage and favor heterolytic cleavage. The proton acceptor can be an external Lewis base9 or a group in the coordination sphere of the metal with sufficiently basic free pairs.10 The σbond metathesis implies the transfer of a hydrogen atom from the arene to another ligand in a concerted fashion.11 Because of steric effects, the C−H activations of para and meta positions of haloarenes are kinetically favored.2e,12 However, the ortho activation is thermodynamically preferred, in particular when an unsaturated species is formed and some secondary metal− halogen interaction is possible.13 The broad applications of N-heterocyclic carbenes as organocatalysts 14 and excellent ligands in coordination chemistry and catalysis15 have turned them into relevant tools © 2014 American Chemical Society

of modern chemistry. Recent reports have further shown that they can also undergo a range of metal-promoted reactions, including C−H, C−N, and C−C bond activations, which enlarges their role from excellent auxiliary ligands to reactive centers attached to a transition metal.16 2-Substituted pyridines, quinolines, and related heterocycles undergo ruthenium-, osmium-,17 and iridium-promoted18 1,2-hydrogen shifts from carbon to nitrogen to afford six-membered N-heterocyclic carbene derivatives bearing an NH wingtip,19 which play a main role in the metal-promoted direct functionalization of nitrogen heterocycles20 and afford interesting intramolecular frustrated Lewis pairs by deprotonation.21 The hydridotris(pyrazolyl)borate (Tp) complex [OsTp(κ1OCMe2)2(PiPr3)]BF4 (1) promotes the 1,2-hydrogen shift from carbon to nitrogen of 2-methylpyridine to afford the pyridylidene derivative [OsTp{κ 1 -C[HNC 5 H 3 Me]}(κ 1 OCMe2)(PiPr3)]BF4 (2 in eq 1).20d Now we show that the

Os−pyridylidene bond is stronger than the Os−PiPr3 bond and that the pyridyl ligand generated by deprotonation of the NH wingtip promotes the selective meta-C−H bond activation of 1,3-disubstituted chlorobenzenes. Received: February 27, 2014 Published: April 4, 2014 1851

dx.doi.org/10.1021/om500204s | Organometallics 2014, 33, 1851−1858

Organometallics

■

Article

RESULTS AND DISCUSSION Substitution of the Phosphine in the Presence of the Pyridylidene. Ethylene displaces both the acetone and phosphine ligands of 2, while the pyridylidene group remains coordinated to the metal center. The reaction takes place by stages, in fluorobenzene, under 2 atm of olefin (Scheme 1). Scheme 1

Figure 1. Molecular diagram of the cation of 4. Selected bond lengths (Å) and angles (deg): Os−N(2) 2.123(5), Os−N(4) 2.111(5), Os− N(6) 2.185(5), Os−C(1) 2.099(6), Os−C(7) 2.191(6), Os−C(8) 2.176(7), Os−C(9) 2.182(7), Os−C(10) 2.161(6), C(7)−C(8) 1.371(10), C(9)−C(10) 1.354(10); N(2)−Os−N(4) 88.64(18), N(4)−Os−N(6) 83.96(19), N(2)−Os−N(6) 80.13(18), C(1)−Os− N(6) 159.3(2).

CH2)2(PiPr3)]BF4 (from 2.175(4) to 2.220(4) Å)12g and other osmium−olefin complexes.23 Similarly, the olefinic bond lengths of 1.371(10) Å (C(7)−C(8)) and 1.354(10) Å (C(9)−C(10)) are statistically identical with those of [OsTp(η2-CH2CH2)2(PiPr3)]BF4 (1.388(6) and 1.376(6) Å)12g and are within the range reported for transition-metal olefin complexes (1.340−1.445 Å).24 Although the carbon atoms of each ethylene are inequivalent, the olefins are chemically equivalent. However, the ethylene hydrogen atoms display an AA′BB′ spin system centered at 3.18 ppm in the 1H NMR spectrum at room temperature, indicating a rapid rotation of the olefins around the osmium−ethylene bonds. In agreement with this, the 13C{1H} NMR spectrum shows only one ethylene resonance at 58.9 ppm, even at −80 °C, along with the pyridylidene C(1) signal at 178.7 ppm. The most noticeable resonance due to the pyridylidene ligand in the 1H NMR spectrum is a broad signal at 11.28 ppm due to the NH hydrogen. The NH wingtip of 3 and 4 undergoes deprotonation. Treatment of tetrahydrofuran solutions of these compounds with 1.2 equiv of potassium tert-butoxide at room temperature leads to the corresponding pyridyl derivatives [OsTp{κ1C[NC5H3Me]}(η2-CH2CH2)(PiPr3)] (5) and [OsTp{κ1C[NC5H3Me]}(η2-CH2CH2)2] (6), which were isolated as red and white solids in 82% and 97% yields, respectively. The reactions are reversible. The addition of 1.0 equiv of HBF4· OEt2 to dichloromethane solutions of 5 and 6 regenerates 3 and 4. The most noticeable feature in the 1H NMR spectra of 5 and 6 in benzene-d6, at room temperature, is the absence of any NH resonance. The olefins rotate around the osmium−ethylene bonds in both compounds. As a consequence, the ethylene hydrogen atoms display AA′BB′ spin systems centered at 3.30 ppm for 5 and 3.05 ppm for 6, whereas the ethylene carbon atoms give rise to singlets at 48.6 ppm for 5 and 58.8 ppm for 6 in the 13C{1H} NMR spectra, which show the resonances due to the metalated pyridyl carbon atom at 178.8 ppm for 5 and 175.9 ppm for 6. The 31P{1H} NMR spectrum of 5 contains a

Initially, the replacement of acetone gives rise to the mono(olefin) derivative [OsTp{κ 1 -C[HNC 5 H 3 Me]}(η 2 CH2CH2)(PiPr3)]BF4 (3), which was isolated as a yellow solid in 88% yield, after 1 h, at room temperature. The displacement of the phosphine occurs at 120 °C. At this temperature, the formation of the bis(olefin) compound [OsTp{κ1-C[HNC5H3Me]}(η2-CH2CH2)2]BF4 (4) arises. This complex was isolated as a yellow solid in 60% yield. The presence of the coordinated olefin in 3 is strongly supported by the 1H and 13C{1H} NMR spectra of the obtained solid, in dichloromethane-d2. The 1H NMR spectrum at room temperature shows a broad singlet at 3.22 ppm for the ethylene hydrogen atoms, which is split into the expected ABCD part of an ABCDX (X = 31P) spin system at −40 °C, along with the pyridylidene NH resonance at 9.83 ppm. The 13 C{1H} NMR spectrum is consistent with the 1H NMR spectrum. Thus, the spectrum at room temperature contains at 48.2 ppm a singlet for the ethylene carbon atoms, which is split into two signals at 65.6 and 34.0 ppm at −40 °C, along with the metalated pyridylidene resonance at 185.1 ppm. A singlet at −19.5 ppm in the 31P{1H} NMR spectrum is also characteristic of this compound. Complex 4 has been characterized by X-ray diffraction analysis. Figure 1 shows a view of the cation of the salt. The distribution of the ligands around the metal center can be described as a distorted octahedron with the coordinating nitrogen atoms of the Tp ligand in fac sites. The metal coordination sphere is completed by the olefins and the pyridylidene group containing the NH wingtip pointing to the olefins. The Os−pyridylidene separation of 2.099(6) Å (Os− C(1)) agrees well with those reported for Os−NHC compounds with normal coordination of the NHC unit.22 The coordinated ethylene molecules lie to the sides of a symmetry plane containing the N(6)−N(7) pyrazolyl ring, the osmium atom, and the pyridylidene ligand. The C−C double bonds are disposed in a parallel manner with Os−C distances between 2.161(6) and 2.191(6) Å, which compare well with those found in the related complex [OsTp(η 2-CH2 1852


Organometallics

Article

singlet at −21.5 ppm, in agreement with the presence of the phosphine ligand in this compound. Selective meta-CH Bond Activation of 1,3-Disubstituted Chlorobenzenes. 1-Chloro-3-fluorobenzene, 1,3-dichlorobenzene, and 3-chlorotoluene displace the pyridyl ligand of 6. Thus, stirring of the haloarene solutions of this compound, for 4 days, at 60 °C leads to the corresponding haloaryl derivatives [OsTp(3,5-C 6 H 3 ClF)(η 2 -CH 2 CH 2 ) 2 ] (7), [OsTp(3,5-C6H3Cl2)(η2-CH2CH2)2] (8), and [OsTp(3,5CH3C6H3Cl)(η2-CH2CH2)2] (9) and pyridine (Scheme 2). Scheme 2

Figure 2. Molecular diagram of 7. Selected bond lengths (Å) and angles (deg): Os−N(1) 2.137(3), Os−N(3) 2.183(3), Os−N(5) 2.108(3), Os−C(1) 2.135(4), Os−C(7) 2.173(4), Os−C(8) 2.175(4), Os−C(9) 2.181(4), Os−C(10) 2.174(4), C(7)−C(8) 1.390(6), C(9)−C(10) 1.392(6); N(1)−Os−N(3) 79.77(11), N(3)−Os− N(5) 83.17(12), N(1)−Os−N(5) 88.33(12), C(1)−Os−N(3) 159.16(13).

whereas the resonances corresponding to the metalated aryl carbon atoms are observed between 154 and 151 ppm. The formation of 7−9 can be rationalized according to Scheme 3. Complex 6 is saturated; its activation requires the release of some group from the coordination sphere of the metal center. Because both olefins are present in the reaction products, the leaving group should be a pyrazolyl arm of the Tp ligand. The dissociation, which leads to the five-coordinate intermediate A, appears to be the rate-determining step of the overall C−H bond activation process. In agreement with this, an inverse kinetic isotope effect25 with kH/kD = 0.74(7) is observed for the formation of 8. Once intermediate A is generated, the coordination of the less hindered C−H bond of the haloarene to the metal center should afford the key species B, containing the pyridyl ligand and the arene coordinated at the metal center. At first glance, intermediate B could evolve into 7−9 in three different manners: (i) oxidative addition of the coordinated C−H bond of the haloarene and the subsequent reductive elimination of pyridine (pathway a), (ii) heterolytic rupture of the coordinated C−H bond of the haloarene promoted by the basic nitrogen atom of the pyridyl group and subsequent retrotautomerization of the resulting pyridylidene into pyridine (pathway b), and (iii) σ-bond metathesis between the haloarene and pyridyl ligands (pathway c). Pathways a and b are both unlikely. The expected low nucleophilicity of the metal center of B, containing two acidic ethylene ligands, puts at a disadvantage the oxidative addition of the haloarene C−H bond to give C; in addition, the reductive elimination of pyridine to afford D is hard, given the saturated character of the d4 intermediate C.26 On the other hand, one should expect that, when C is formed, it also evolves by migratory insertion of one of the ethylene molecules into the Os−H bond to generate the unsaturated ethyl derivative E, which could be stabilized by coordination of the free pyrazolyl arm of the Tp ligand to give F. Before the stabilization, species E should easily release hydroarylation products,27 as a result of

These complexes, which are the result of the selective meta-CH bond activation of the haloarene solvents, were isolated as white (7), orange (8), and pale orange (9) solids in 51%, 93%, and 80% yields, respectively. The activation of the meta position of the haloarenes was confirmed by means of the X-ray diffraction analysis of 7. Its structure (Figure 2) proves the equidistant position, at the sixmembered ring, of the metal fragment with regard to the halogen substituents. The distribution of ligands around the osmium atom is the same as that of 4, with the haloaryl ligand occupying the pyridylidene position. The osmium−ethylene distances, between 2.173(4) and 2.181(4) Å, as well as the olefinic bond lengths of 1.390(6) and 1.392(6) Å are statistically identical with those of 4, whereas the Os−aryl separation of 2.135(4) Å is slightly longer than the Os− pyridylidene distance. The 1H and 13C{1H} NMR spectra of 7−9, in benzene-d6, at room temperature are consistent with the structure shown in Figure 2. In agreement with the position of the aryl substituents, the 1H NMR spectra of 7 and 9 contain three aryl resonances, between 6.8 and 6.2 ppm, with 1:1:1 intensity ratio and H−H coupling constants smaller than 2 Hz, whereas that of 8 shows two aryl resonances at 7.08 and 6.53 ppm with a 1:2 intensity ratio. The ethylene hydrogen atoms display AA′BB′ spin systems at about 2.6 ppm for the three compounds. In agreement with 6, the ethylene singlet is observed at about 57 ppm in the 13C{1H} NMR spectra, 1853


Organometallics

Article

Scheme 3

by sparging with argon and then passing through active alumina using a solvent purification apparatus. The starting material [OsTp{κ1C[HNC5H3Me]}(κ1-OCMe2)(PiPr3)]BF4 (2) was prepared according to the published method.20d 1H, 31P{1H}, and 13C{1H} NMR spectra were recorded on a 300 or 400 MHz instrument. Chemical shifts (expressed in parts per million) are referenced to residual solvent peaks (1H, 13C) or external H3PO4 (31P). Coupling constants, J, are given in hertz. All coupling constants for the pyrazolyl proton resonances were about 2 Hz. Spectral assignments were achieved by 1 H−1H COSY, NOESY, 1H{31P}, 13C APT, 1H−13C HSQC, and 1 H−13C HMBC experiments. Infrared spectra were recorded as neat solids. High-resolution electrospray mass spectra were acquired using a hybrid quadrupole time-of-flight spectrometer. Preparation of [OsTp{κ1-C[HNC5H3Me]}(η2-CH2CH2)(PiPr3)]BF4 (3). A Fischer−Porter bottle was charged with a solution of 2 (250 mg, 0.312 mmol) in 5 mL of fluorobenzene. The bottle was pressurized to 2 atm of ethylene, and the solution was stirred for 1 h at room temperature. During this time a yellow solution was formed. The solvent was removed in vacuo, and the addition of 2 mL of diethyl ether caused the precipitation of a yellow solid, which was washed with diethyl ether (3 × 3 mL) and dried in vacuo. Yield: 210 mg (88%). Anal. Calcd for C26H42B2F4N7OsP: C, 40.48; H, 5.49, N, 12.71. Found: C, 40.96; H, 5.62; N, 13.01. HRMS (electrospray, m/z): calcd for C26H42BN7OsP [M]+ 686.2947, found 686.2946; calcd for C24H38BN7OsP [M − C2H4]+ 658.2634, found 658.2684. IR (ATR, cm−1): ν(NH) 3360 (br), ν(BH) 2487 (w), ν(BF4) 1044 (s). 1H NMR (300 MHz, CD2Cl2, 298 K): δ 9.83 (br, 1H, NH), 8.04 (d, 1H, Tp), 7.88 (d, 1H, Tp), 7.81 (d, 1H, Tp), 7.74 (d, 1H, Tp), 7.61 (d, 1H, Tp), 7.36−7.25 (m, 2H, Py), 6.68−6.67 (overlapping signals, 2H, Py + Tp), 6.58 (t, 1H, Tp), 6.32 (t, 1H, Tp), 6.10 (t, 1H, Tp), 3.22 (br s, 4H, CH2CH2), 2.66 (m, 3H, PCHCH3), 2.22 (s, 3H, CH3-Py), 1.05 (dd, JH‑P = 12.0, JH‑H = 7.2, 9H, PCHCH3), 0.88 (dd, JH‑P = 12.6, JH‑H = 7.2, 9H, PCHCH3). 31P{1H} NMR (121.48 MHz, CD2Cl2, 298 K): δ −19.5 (br). 13C{1H} NMR (75.45 MHz, CD2Cl2, 298 K): δ 185.1 (s, OsCNH), 150.5 (s, Cipso Py), 146.3, 143.2, 142.4, 139.3, 138.0, 136.1 (all s, Tp), 136.0, 116.6 (both s, Py), 109.0, 107.3, 106.9 (all s, Tp), 48.2 (s, CH2CH2), 26.0 (d, JC‑P = 24, PCHCH3), 20.3 (s,

a reductive elimination process. However, they were not detected during the spectroscopic monitoring of the reactions. Saturated intermediates such as C and F were not also observed. Although the heterolytic cleavage (pathway b) of the haloarene C−H bond to form the pyridylidene intermediate G should be favored, in view of the expected marked electrophilicity of the metal center of B, the retrotautomerization of the heterocycle should occur through the hydride intermediate C, according to previous DFT calculations on a bis(phosphine) system.17e Therefore, σ-bond metathesis (pathway c) between the haloarene and the pyridyl group seems to be the most probable mechanism for the formation of 7−9. A similar proposal has been done for the reactions of [OsTp(CH2CH2PiPr3)(η2-CH2CH2)2]BF4 with fluorobenzene and 1,3-difluorobenzene, which yield [OsTp(3,5-C6H3FX)(η2CH2CH2)2] (X = H, F).12g

■

CONCLUDING REMARKS This study reveals that the tautomerization of pyridylidene Nheterocyclic carbene ligands with a NH- wingtip and the release of the resulting N-coordinated heterocycle, from the metal coordination sphere of an OsTp fragment, is disfavored with regard to the substitution of strong coordinating monodentate basic alkylphosphines by ethylene. Furthermore, it demonstrates that the pyridyl group resulting from the deprotonation of the NH wingtip is able to promote the selective meta-C−H bond activation of 1,3-substituted chlorobenzenes, most probably through a σ-bond metathesis mechanism.

■

EXPERIMENTAL SECTION

General Methods and Instrumentation. All manipulations were performed with rigorous exclusion of air using Schlenk tube or glovebox techniques. Solvents were dried by the usual procedures and distilled under argon prior to use or obtained oxygen- and water-free 1854


Organometallics

Article

298 K): δ 7.66 (d, 1H, Tp), 7.32 (d, 3H, Tp), 6.93 (d, 2H, Tp), 6.56 (m, 2H, Py), 5.91 (t, 1H, Tp), 5.69 (t, 2H, Tp), 5.57 (d, JH‑H = 7.5, 1H, Py), 3.05 (AA′BB′ spin system, δA = δA′ = 3.06, δB = δB′ = 3.04, JA‑A′ = JB‑B′ = 18.0, JA‑B = JA′‑B′ = −1.5, JA‑B′ = JA′‑B = 8.5, 8H, CH2 CH2), 2.69 (s, 3H, CH3 Py). 13C{1H} NMR (75.45 MHz, C6D6, 298 K): δ 175.9 (s, OsCN), 154.8 (s, Cipso Py), 143.6, 139.9, 135.0, 134.4 (all s, Tp), 131.4, 130.1, 115.3 (all s, Py), 106.6, 106.2 (both s, Tp), 58.8 (s, CH2CH2), 25.6 (s, CH3-Py). Reaction of [OsTp{κ1-C[NC5H3Me]}(η2-CH2CH2)2] (6) with HBF4. An NMR tube containing a colorless solution of 6 (20 mg, 0.036 mmol) in 0.5 mL of dichloromethane-d2 was treated with HBF4· Et2O (5.0 μL, 0.036 mmol). The solution immediately turned yellow. After 30 min at room temperature, the 1H NMR spectrum showed the presence of 4. Preparation of [OsTp(3,5-C6H3ClF)(η2-CH2CH2)2] (7). A solution of 6 (50 mg, 0.09 mmol) in 0.5 mL of 1-chloro-3fluorobenzene was heated to 333 K for 4 days. During this time, an orange solution was formed. The solvent was removed in vacuo, and an orange solid precipitated. AgBF4 (5.9 mg, 0.03 mmol) was added to an acetone solution of the orange solid at room temperature. After 30 min the solvent was evaporated to dryness to give a yellow solid, which was extracted with diethyl ether (10 mL). The solvent was removed in vacuo, and a white solid precipitated. Yield: 27 mg (51%). Anal. Calcd for C19H21BClFN6Os: C, 38.75; H, 3.59; N, 14.27. Found: C, 39.09; H, 3.63; N, 14.58. HRMS (electrospray, m/z): calcd for C17H16BClFN6Os [M − C2H4 − H]+ 561.0804, found 561.0817. 1H NMR (300 MHz, C6D6, 298 K): δ 7.51 (d, 1H, Tp), 7.21 (d, 3H, Tp), 6.78 (br d, JH‑F = 8.4, 1H, H4 C6H3ClF), 6.63 (d, 2H, Tp), 6.60 (br, 1H, H2 C6H3ClF), 6.20 (br d, JH‑F = 11.3, 1H, H6 C6H3ClF), 5.83 (t, 1H, Tp), 5.64 (t, 2H, Tp), 2.59 (AA′BB′ spin system, δA = δA′ = 2.70, δB = δB′ = 2.48, JA‑A′ = JB‑B′ = 12.0, JA‑B = JA′‑B′ = −0.8, JA‑B′ = JA′‑B = 8.0, 8H, CH2CH2). 19F NMR (282.38 MHz, C6D6, 298 K): δ −116.8 (dd, JF‑H = 11.3, JF‑H′ = 8.4). 13C{1H} NMR (75.45 MHz, C6D6, 298 K): δ 160.8 (d, JC‑F = 247, CF), 153.9 (d, JC‑F = 3, OsC), 143.8, 139.3, 135.1 (all s, Tp), 134.9 (d, JC‑F = 2, C2 C6H3ClF), 134.4 (s, Tp), 131.0 (d, JC‑F = 10, CCl), 123.8 (d, JC‑F = 17, C6 C6H3ClF), 108.9 (d, JC‑F = 25, C4 C6H3ClF), 106.5, 106.4 (both s, Tp), 56.7 (s, CH2CH2). Preparation of [OsTp(3,5-C6H3Cl2)(η2-CH2CH2)2] (8). A solution of 6 (50 mg, 0.09 mmol) in 0.5 mL of 1,3-dichlorobenzene was heated to 333 K for 4 days. During this time, a dark orange solution was formed. The solvent was evaporated to dryness to give an orange solid, which was extracted with n-pentane (10 mL). The solvent was removed in vacuo to yield a white solid. Yield: 51 mg (93%). Anal. Calcd for C19H21BCl2N6Os·0.5C6H4Cl2: C, 38.92; H, 3.41; N, 12.38. Found: C, 38.83; H, 3.72; N, 12.37. HRMS (electrospray, m/z): calcd for C19H21BCl2N7Os [M − C2H4 + CH3CN + H]+ 620.0921, found 620.2233. 1H NMR (300 MHz, C6D6, 298 K): δ 7.50 (d, 1H, Tp), 7.23 (d, 2H, Tp), 7.21 (d, 1H, Tp), 7.08 (br, 1H, H4 C6H3Cl2), 6.60 (d, 2H, Tp), 6.53 (br, 2H, H2 and H6 C6H3Cl2), 5.83 (t, 1H, Tp), 5.67 (t, 2H, Tp), 2.58 (AA′BB′ spin system, δA = δA′ = 2.69, δB = δB′ = 2.47, JA‑A′ = JB‑B′ = 12.5, JA‑B = JA′‑B′ = −0.9, JA‑B′ = JA′‑B = 10.0, 8H, CH2CH2). 13C{1H} NMR (75.45 MHz, C6D6, 298 K): δ 153.8 (s, OsC), 144.0, 139.6 (both s, Tp), 137.6 (s, C2 and C6 C6H3Cl2), 135.4, 134.7 (both s, Tp), 131.7 (s, CCl), 121.6 (s, C4 C6H3Cl2), 106.7 (s, Tp), 57.0 (s, CH2CH2). Preparation of [OsTp(3,5-CH3C6H3Cl)(η2-CH2CH2)2] (9). A solution of 6 (50 mg, 0.09 mmol) in 0.5 mL of 3-chlorotoluene was heated to 333 K for 4 days. During this time, an orange solution was formed. The solvent was evaporated to dryness to give an orange solid that was extracted with n-pentane (10 mL). The solvent was removed in vacuo to yield a pale orange solid. Yield: 42 mg (80%). Anal. Calcd for C20H24BClN6Os: C, 41.07; H, 4.14; N, 14.37. Found: C, 40.69; H, 4.17; N, 14.63. HRMS (electrospray, m/z): calcd for C20H25BClN6Os [M + H+] 587.1525, found 587.1618, calcd for C16H17BClN6Os [M − 2 C2H4 + H]+ 531.0898, found 531.0895. 1H NMR (300 MHz, C6D6, 298 K): δ 7.58 (d, 1H, Tp), 7.27 (d, 2H, Tp), 7.25 (d, 1H, Tp), 6.85 (br, 1H, H2 CH3C6H3Cl), 6.73 (d, 2H, Tp), 6.56 (br, 1H, H6 CH3C6H3Cl), 6.31 (br, 1H, H4 CH3C6H3Cl), 5.86 (t, 1H, Tp), 5.68 (t, 2H, Tp), 2.67 (AA′BB′ spin system, δA = δA′ = 2.76, δB = δB′ = 2.57, JA‑A′ = JB‑B′ = 13.0, JA‑B = JA′‑B′ = −1.0, JA‑B′ = JA′‑B = 11.5, 8H, CH2

CH3-Py), 20.1 (s, PCHCH3), 19.8 (s, PCHCH3). 1H NMR (300 MHz, CD2Cl2, 233 K): δ 3.3 (br, 1H, CH2CH2), 3.1 (br, 3H, CH2 CH2). 13C{1H} NMR (75.45 MHz, CD2Cl2, 233 K): δ 65.6 (s, CH2 CH2), 34.0 (s, CH2CH2). Preparation of [OsTp{κ1-C[HNC5H3Me]}(η2-CH2CH2)2]BF4 (4). A Fischer−Porter bottle was charged with a solution of 2 (250 mg, 0.312 mmol) in 4 mL of fluorobenzene. The bottle was pressurized to 2 atm of ethylene, and the solution was stirred for 2 h at 393 K. After this time, it was warmed to room temperature and the solvent was removed in vacuo. The addition of diethyl ether (2 mL) caused the precipitation of a yellow solid, which was washed with diethyl ether (3 × 3 mL) and dried in vacuo. Yield: 120 mg (60%). Anal. Calcd for C19H25B2F4N7Os: C, 35.70; H, 3.94; N, 15.34. Found: C, 35.93; H, 3.96; N, 15.45. HRMS (electrospray, m/z): calcd for C 19 H 25 BN 7 Os [M] + 554.1768, found 554.1718; calcd for C17H21BN7Os [M − C2H4]+ 526.1564, found 526.1584. IR (ATR, cm−1): ν(NH) 3323 (br), ν(BH) 2467 (w), ν(BF4) 1052 (s). 1H NMR (300 MHz, CD2Cl2, 298 K): δ 11.28 (br, NH), 8.07 (d, 1H, Tp), 7.85 (d, 2H, Tp), 7.76 (d, 1H, Tp), 7.15 (t, JH‑H = 7.8, 1H, Py), 7.01 (d, 2H, Tp), 6.96 (d, JH‑H = 7.8, 1H, Py), 6.40 (t, 1H, Tp), 6.26 (t, 2H, Tp), 6.06 (d, JH‑H = 7.8, 1H, Py), 3.18 (AA′BB′ spin system, δA = δÁ = 3.23, δB = δB́ = 3.12, JA‑A′ = JB‑B′ = 12.5, JA‑B = JA′‑B′ = −0.5, JA‑B′ = JA′‑B = 9.5, 8H, CH2CH2), 2.67 (s, 3H, CH3-Py). 13C{1H} NMR (75.45 MHz, CD2Cl2, 298 K): δ 178.7 (s, OsCNH), 152.5 (s, Cipso Py), 144.5, 139.9 (both s, Tp), 138.3 (s, Py), 137.1, 136.5 (both s, Tp), 136.2, 119.8 (both s, Py), 107.7, 107.4 (both s, Tp), 58.9 (s, CH2CH2), 20.1 (s, CH3-Py). Preparation of [OsTp{κ1-C[NC5H3Me]}(η2-CH2CH2)(PiPr3)] (5). A solution of 3 (450 mg, 0.583 mmol) in 4 mL of tetrahydrofuran was treated with potassium tert-butoxide (78.5 mg, 0.700 mmol) and stirred at room temperature for 30 min. During this time a red solution was formed. The solvent was evaporated to dryness to give a red solid that was extrated with toluene (20 mL). The solvent was removed in vacuo, and a red solid precipitated, which was washed with cold npentane and dried in vacuo. Yield: 325 mg (82%). Anal. Calcd for C26H41BN7OsP: C, 45.68; H, 6.04; N, 14.34. Found: C, 46.05; H, 5.98; N, 14.52. HRMS (electrospray, m/z): calcd for C26H42BN7OsP [M + H]+ 686.2869, found 686.2834. 1H NMR (300 MHz, C6D6, 298 K): δ 8.12 (d, 1H, Tp), 7.83 (d, 1H, Tp), 7.54 (d, 1H, Tp), 7.50 (d, 1H, Tp), 7.31 (d, 1H, Tp), 6.85 (d, 1H, Tp), 6.57 (t, JH‑H = 7.8, 1H, Py), 6.48 (d, JH‑H = 7.8, 1H, Py), 5.99 (t, 1H, Tp), 5.91 (t, 1H, Tp), 5.69 (m, 2H, Tp + Py), 3.30 (AA′BB′X spin system (X = 31P), δA = δA′ = 3.40, δB = δB′ = 3.21, JA‑A′ = JB‑B′ = 11.5, JA‑B = JA′‑B′ = −0.7, JA‑B′ = JA′‑B = 7.5, JA‑X = JA′‑X = JB‑X = JB′‑X = 2, 4H, CH2CH2), 2.98 (m, 3H, PCHCH3), 2.65 (s, 3H, CH3-Py), 1.10 (dd, JH‑P = 10.4, JH‑H = 7.5, 9H, PCHCH3), 0.84 (dd, JH‑P = 12.0, JH‑H = 7.2, 9H, PCHCH3). 31P{1H} NMR (121.48 MHz, C6D6, 298 K): δ −21.5 (s). 13C{1H} NMR (75.45 MHz, C6D6, 298 K): δ 178.8 (d, JC‑P = 7, OsCN), 153.4 (s, Cipso Py), 146.8, 146.4, 139.0, 135.9, 135.4, 134.2, 133.3 (all s, Tp), 133.2, 130.7, 114.0 (all s, Py), 106.3, 105.7 (both s, Tp), 48.6 (s, CH2 CH2), 25.4 (s, CH3-Py), 25.0 (d, JC‑P = 21, PCHCH3), 20.8 (s, PCHCH3), 20.4 (d, JC‑P = 4, PCHCH3). Reaction of [OsTp{κ1-C[NC5H3Me]}(η2-CH2CH2)(PiPr3)] (5) with HBF4. An NMR tube containing a red solution of 5 (20 mg, 0.029 mmol) in 0.5 mL of dichloromethane-d2 was treated with HBF4· Et2O (4.0 μL, 0.029 mmol). The solution immediately turned yellow. After 30 min at room temperature, the 1H and 31P{1H} NMR spectra showed the presence of 3. Preparation of [OsTp{κ1-C[NC5H3Me]}(η2-CH2CH2)2] (6). A solution of 4 (240 mg, 0.375 mmol) in 4 mL of tetrahydrofuran was treated with potassium tert-butoxide (42,1 mg, 0.375 mmol) and stirred at room temperature for 15 min. During this time a dark yellow solution was formed. The solvent was evaporated to dryness to give a solid that was extracted with toluene (20 mL). The solvent was removed in vacuo, and a white solid precipitated, which was washed with cold n-pentane and dried in vacuo. Yield: 200 mg (97%). Anal. Calcd for C19H24BN7Os: C, 41.38; H, 4.39; N, 17.78. Found: C, 41.33; H, 4.64; N, 17.54. HRMS (electrospray, m/z): calcd for C19H25BN7Os [M + H]+ 554.1878, found 554.1672; calcd for C17H21BN7Os [M − C2H4 + H]+ 526.1564, found 526.1549. 1H NMR (300 MHz, C6D6, 1855


Organometallics

Article

CH2), 2.03 (s, 3H, CH3C6H3Cl). 13C{1H} NMR (75.45 MHz, C6D6, 298 K): δ 151.5 (s, OsC), 144.1, 139.6 (both s, Tp), 138.7, 136.5 (both s, C4 and C6 CH3C6H3Cl), 135.7 (s, CCH3) 135.2, 134.5 (both s, Tp), 131.5 (s, CCl), 122.6 (s, C2 CH3C6H3Cl), 106.7, 106.4, 106.3 (all s, Tp), 56.4 (s, CH2CH2), 21.3 (s, CH3C6H3Cl). Determination of the Kinetic Isotope Effect (KIE). In an NMR tube, 6 (20 mg, 0.036 mmol) was solved in 1,3-dicholorobenzene (0.5 mL) or 1,3-dicholorobenzene-d4 (0.5 mL), respectively. The tubes were heated to 333 K. The reactions were monitored by 1H NMR at intervals of time. The decrease of the intensity (I) of a chosen signal corresponding to the starting compound, related to an external patron (1,4-dioxane) vs time (in h) fits an exponential decay function. ln I vs time fits a linear function from which kobsH for the reaction with 1,3dichlorobenzene and kobsD for the reaction with 1,3-dichlorobenzened4 can be obtained (kobsH = 0.17(1) h−1 and kobsD = 0.23(7) h−1). kobsH/kobsD gives a KIE value of 0.74(7). Structural Analysis of Complexes 4 and 7. Crystals were obtained by slow diffusion of diethyl ether into saturated solutions in CH2Cl2 for 4 or from saturated solutions of 7 in pentane. X-ray data were collected for the complexes on a diffractometer equipped with a normal-focus, 2.4 kW sealed-tube source (Mo radiation, λ = 0.71073 Å) operating at 50 kV and 30 mA. Data were collected over the complete sphere. Each frame exposure time was 20 s covering 0.3° in ω. Data were corrected for absorption by using a multiscan method applied with the SADABS program.28 The structures were solved by Patterson or direct methods and refined by full-matrix least squares on F2 with SHELXL97,29 including isotropic and subsequently anisotropic displacement parameters. The hydrogen atoms were observed in the least Fourier maps or calculated and were refined freely or were refined using a restricted riding model. Crystal data for 4: C19H25BN7Os·BF4·CH2Cl2, Mw 724.21, colorless, irregular block (0.33 × 0.06 × 0.04), orthorhombic, space group Pca21, = 12.8642(12) Å, b = 13.5832(13) Å, c = 14.4363(14) Å, V = 2522.6(4) Å3, Z = 4, Z′ = 1, Dcalcd = 1.907 g cm−3, F(000) = 1408, T = 100(2) K, μ = 5.321 mm−1, 29042 measured reflections (2θ = 3− 58°, ω scans 0.3°), 5979 unique reflections (Rint = 0.0360), minimum/ maximum transmission factors 0.660/0.862, final agreement factors R1 = 0.0332 (4889 observed reflections, I > 2σ(I)) and wR2 = 0.0810, Flack parameter −0.012(12), 5979/10/357 data/restraints/parameters, GOF = 1.025, largest peak and hole 0.930 and −1.004 e/Å3. Crystal data for 7: C19H21BClFN6Os, Mw 588.88, yellow, irregular block (0.25 × 0.15 × 0.06), orthorhombic, space group P21/n, a = 10.5697(5) Å, b = 12.2481(6) Å, c = 15.7824(8) Å, β = 98.1570(10)°, V = 2022.50(17) Å3, Z = 4, Z′ = 1, Dcalcd = 1.934 g cm−3, F(000) = 1136, T = 100(2) K, μ = 6.464 mm−1, 23548 measured reflections (2θ = 3−58°, ω scans 0.3°), 4831 unique reflections (Rint = 0.0298), minimum/maximum transmission factors 0.561/0.862, final agreement factors R1 = 0.0275 (4496 observed reflections, I > 2σ(I)) and wR2 = 0.0539, 4831/0/289 data/restraints/parameters, GOF = 1.195, largest peak and hole 1.285 and −1.130 e/Å3.

■

00006)), the DGA (E35), and the European Social Fund (FSE) is acknowledged.

■

(1) (a) Shilov, A. E.; Shul’pin, G. B. Chem. Rev. 1997, 97, 2879. (b) Labinger, J. A.; Bercaw, J. E. Nature 2002, 417, 507. (c) Lersch, M.; Tilset, M. Chem. Rev. 2005, 105, 2471. (d) Balcells, D.; Clot, E.; Eisenstein, O. Chem. Rev. 2010, 110, 749. (2) (a) Mkhalid, I. A. I.; Barnard, J. H.; Marder, T. B.; Murphy, J. M.; Hartwig, J. F. Chem. Rev. 2010, 110, 890. (b) Colby, D. A.; Bergman, R. G.; Ellman, J. A. Chem. Rev. 2010, 110, 624. (c) Wencel-Delord, J.; Dröge, T.; Liu, F.; Glorius, F. Chem. Soc. Rev. 2011, 40, 4740. (d) Ackermann, L. Chem. Rev. 2011, 111, 1315. (e) Hartwig, J. F. Chem. Soc. Rev. 2011, 40, 1992. (f) Kuhl, N.; Hopkinson, M. N.; Wencel-Delord, J.; Glorius, F. Angew. Chem., Int. Ed. 2012, 51, 10236. (3) Webb, J. R.; Bolaño, T.; Gunnoe, T. B. ChemSusChem 2011, 4, 37. (4) (a) Bosque, R.; Clot, E.; Fantacci, S.; Maseras, F.; Eisenstein, O.; Perutz, R. N.; Renkema, K. B.; Caulton, K. G. J. Am. Chem. Soc. 1998, 120, 12634. (b) Fan, L.; Parkin, S.; Ozerov, O. V. J. Am. Chem. Soc. 2005, 127, 16772. (c) Wu, H.; Hall, M. B. Dalton Trans. 2009, 5933. (5) (a) Selmeczy, A. D.; Jones, W. D.; Partridge, M. G.; Perutz, R. N. Organometallics 1994, 13, 522. (b) Renkema, K. B.; Bosque, R.; Streib, W. E.; Maseras, F.; Eisenstein, O.; Caulton, K. G. J. Am. Chem. Soc. 1999, 121, 10895. (c) Carbó, J. J.; Eisenstein, O.; Higgitt, C. L.; Klahn, A. H.; Maseras, F.; Oelckers, B.; Perutz, R. N. J. Chem. Soc., Dalton Trans. 2001, 1452. (d) Esteruelas, M. A.; Lledós, A.; Oliván, M.; Oñate, E.; Tajada, M. A.; Ujaque, G. Organometallics 2003, 22, 3753. (e) Clot, E.; Besora, M.; Maseras, F.; Mégret, C.; Eisenstein, O.; Oelckers, B.; Perutz, R. N. Chem. Commun. 2003, 490. (f) Clot, E.; Oelckers, B.; Klahn, A. H.; Eisenstein, O.; Perutz, R. N. Dalton Trans. 2003, 4065. (g) Evans, M. E.; Burke, C. L.; Yaibuathes, S.; Clot, E.; Eisenstein, O.; Jones, W. D. J. Am. Chem. Soc. 2009, 131, 13464. (h) Tanabe, T.; Brennessel, W. W.; Clot, E.; Eisenstein, O.; Jones, W. D. Dalton Trans. 2010, 39, 10495. (i) Hatnean, J. A.; Beck, R.; Borrelli, J. D.; Johnson, S. A. Organometallics 2010, 29, 6077. (6) (a) Barrio, P.; Castarlenas, R.; Esteruelas, M. A.; Lledós, A.; Maseras, F.; Oñate, E.; Tomás, J. Organometallics 2001, 20, 442. (b) Liu, W.; Welch, K.; Trindle, C. O.; Sabat, M.; Myers, W. H.; Harman, W. D. Organometallics 2007, 26, 2589. (c) Schaub, T.; Fischer, P.; Steffen, A.; Braun, T.; Radius, U.; Mix, A. J. Am. Chem. Soc. 2008, 130, 9304. (d) Johnson, S. A.; Huff, C. W.; Mustafa, F.; Saliba, M. J. Am. Chem. Soc. 2008, 130, 17278. (e) Amii, H.; Uneyama, K. Chem. Rev. 2009, 109, 2119. (f) Clot, E.; Eisenstein, O.; Jasim, N.; Macgregor, S. A.; Mcgrady, J. E.; Perutz, R. N. Acc. Chem. Res. 2011, 44, 333. (g) Johnson, S. A.; Mroz, N. M.; Valdizon, R.; Murray, S. Organometallics 2011, 30, 441. (7) Barrios-Landeros, F.; Carrow, B. P.; Hartwig, J. F. J. Am. Chem. Soc. 2009, 131, 8141. (8) (a) Gatard, S.; Ç elenligil-Ç etin, R.; Guo, C.; Foxman, B. M.; Ozerov, O. V. J. Am. Chem. Soc. 2006, 128, 2808. (b) Ito, J.; Miyakawa, T.; Nishiyama, H. Organometallics 2008, 27, 3312. (c) Puri, M.; Gatard, S.; Smith, D. A.; Ozerov, O. V. Organometallics 2011, 30, 2472. (9) (a) Albrecht, M. Chem. Rev. 2010, 110, 576. (b) Boutadla, Y.; Davies, D. L.; Jones, R. C.; Singh, K. Chem. Eur. J. 2011, 17, 3438. (c) Martín-Ortı ́z, M.; Gómez-Gallego, M.; Ramı ́rez de Arellano, C.; Sierra, M. A. Chem. Eur. J. 2012, 18, 12603. (10) (a) Biswas, B.; Sugimoto, M.; Sakaki, S. Organometallics 2000, 19, 3895. (b) Feng, Y.; Lail, M.; Barakat, K. A.; Cundari, T. R.; Gunnoe, T. B.; Petersen, J. L. J. Am. Chem. Soc. 2005, 127, 14174. (c) Tenn, W. J., III; Young, K. J. H.; Bhalla, G.; Oxgaard, J.; Goddard, W. A., III; Periana, R. A. J. Am. Chem. Soc. 2005, 127, 14172. (d) Tenn, W. J., III; Young, K. J. H.; Oxgaard, J.; Nielsen, R. J.; Goddard, W. A., III; Periana, R. A. Organometallics 2006, 25, 5173. (e) Gunnoe, T. B. Eur. J. Inorg. Chem. 2007, 1185. (f) Ito, J.; Nishiyama, H. Eur. J. Inorg. Chem. 2007, 1114. (g) Ito, J.; Kaneda, T.; Nishiyama, H. Organometallics 2012, 31, 4442. (11) (a) Sadow, A. D.; Tilley, T. D. J. Am. Chem. Soc. 2003, 125, 9462. (b) Buil, M. L.; Esteruelas, M. A.; Goni, E.; Oliván, M.; Oñate, E.

ASSOCIATED CONTENT

S Supporting Information *

CIF files giving positional and displacement parameters, crystallographic data, and bond lengths and angles of compounds 4 and 7. This material is available free of charge via the Internet at http://pubs.acs.org.

■

REFERENCES

AUTHOR INFORMATION

Corresponding Author

*E-mail for M.A.E.: [email protected]. Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS Financial support from the Spanish MINECO (Projects CTQ2011-23459 and Consolider Ingenio 2010 (CSD20071856


Organometallics

Article

Organometallics 2006, 25, 3076. (c) Ma, K.; Piers, W. E.; Parvez, M. J. Am. Chem. Soc. 2006, 128, 3303. (d) Waterman, R. Organometallics 2013, 32, 7249. (12) (a) Ishiyama, T.; Takagi, J.; Hartwig, J. F.; Miyaura, N. Angew. Chem., Int. Ed. 2002, 41, 3056. (b) Ishiyama, T.; Takagi, J.; Ishida, K.; Miyaura, N.; Anastasi, N. R.; Hartwig, J. F. J. Am. Chem. Soc. 2002, 124, 390. (c) Cho, J.-Y.; Tse, M. K.; Holmes, D.; Maleczka, R. E., Jr.; Smith, M. R., III Science 2002, 295, 305. (d) Tellers, D. M.; Yung, C. M.; Arndtsen, B. A.; Adamson, D. R.; Bergman, R. G. J. Am. Chem. Soc. 2002, 124, 1400. (e) Krogh-Jespersen, K.; Czerw, M.; Zhu, K.; Singh, B.; Kanzelberger, M.; Darji, N.; Achord, P. D.; Renkema, K. B.; Goldman, A. S. J. Am. Chem. Soc. 2002, 124, 10797. (f) Hull, K. L.; Sanford, M. S. J. Am. Chem. Soc. 2007, 129, 11904. (g) Bajo, S.; Esteruelas, M. A.; López, A. M.; Oñate, E. Organometallics 2011, 30, 5710. (h) Chow, C.; Patrick, B. O.; Legzdins, P. Organometallics 2012, 31, 8159. (i) Shrestha, R.; Mukherjee, P.; Tan, Y.; Litman, Z. C.; Hartwig, J. F. J. Am. Chem. Soc. 2013, 135, 8480. (13) (a) Brönstrup, M.; Trage, C.; Schröder, D.; Schwarz, H. J. Am. Chem. Soc. 2000, 122, 699. (b) Ben-Ari, E.; Gandelman, M.; Rozenberg, H.; Shimon, L. J. W.; Milstein, D. J. Am. Chem. Soc. 2003, 125, 4714. (c) Wu, F.; Dash, A. K.; Jordan, R. F. J. Am. Chem. Soc. 2004, 126, 15360. (d) Tsang, J. Y. K.; Buschhaus, M. S. A.; Legzdins, P.; Patrick, B. O. Organometallics 2006, 25, 4215. (e) BenAri, E.; Cohen, R.; Gandelman, M.; Shimon, L. J. W.; Martin, J. M. L.; Milstein, D. Organometallics 2006, 25, 3190. (f) DeMott, J. C.; Bhuvanesh, N.; Ozerov, O. V. Chem. Sci. 2013, 4, 642. (14) (a) Enders, D.; Niemeier, O.; Henseler, A. Chem. Rev. 2007, 107, 5606. (b) Bugaut, X.; Glorius, F. Chem. Soc. Rev. 2012, 41, 3511. (15) (a) Bourissou, D.; Guerret, O.; Gabbaï, F. P.; Bertrand, G. Chem. Rev. 2000, 100, 39. (b) Crudden, C. M.; Allen, D. P. Coord. Chem. Rev. 2004, 248, 2247. (c) Glorius, F. Top. Organomet. Chem. 2007, 21, 1. (d) Dı ́ez-González, S.; Marion, N.; Nolan, S. P. Chem. Rev. 2009, 109, 3612. (e) Schuster, O.; Yang, L.; Raubenheimer, H. G.; Albrecht, M. Chem. Rev. 2009, 109, 3445. (16) (a) Jazzar, R. F. R.; Macgregor, S. A.; Mahon, M. F.; Richards, S. P.; Whittlesey, M. K. J. Am. Chem. Soc. 2002, 124, 4944. (b) Dorta, R.; Stevens, E. D.; Nolan, S. P. J. Am. Chem. Soc. 2004, 126, 5054. (c) Burling, S.; Mahon, M. F.; Paine, B. M.; Whittlesey, M. K.; Williams, J. M. J. Organometallics 2004, 23, 4537. (d) Cabeza, J. A.; del Rı ́o, I.; Miguel, D.; Sánchez-Vega, M. G. Chem. Commun. 2005, 3956. (e) Burling, S.; Mahon, M. F.; Powell, R. E.; Whittlesey, M. K.; Williams, J. M. J. J. Am. Chem. Soc. 2006, 128, 13702. (f) Corberán, R.; Sanaú, M.; Peris, E. Organometallics 2006, 25, 4002. (g) Ellul, C. E.; Mahon, M. F.; Saker, O.; Whittlesey, M. K. Angew. Chem., Int. Ed. 2007, 46, 6343. (h) Diggle, R. A.; Macgregor, S. A.; Whittlesey, M. K. Organometallics 2008, 27, 617. (i) Burling, S.; Mas-Marzá, E.; Valpuesta, J. E. V.; Mahon, M. F.; Whittlesey, M. K. Organometallics 2009, 28, 6676. (j) Bolaño, T.; Buil, M. L.; Esteruelas, M. A.; Izquierdo, S.; Lalrempuia, R.; Oliván, M.; Oñate, E. Organometallics 2010, 29, 4517. (17) (a) Esteruelas, M. A.; Fernández-Alvarez, F. J.; Oñate, E. J. Am. Chem. Soc. 2006, 128, 13044. (b) Buil, M. L.; Esteruelas, M. A.; Garcés, K.; Oliván, M.; Oñate, E. J. Am. Chem. Soc. 2007, 129, 10998. (c) Esteruelas, M. A.; Fernández-Alvarez, F. J.; Oñate, E. Organometallics 2007, 26, 5239. (d) Buil, M. L.; Esteruelas, M. A.; Garcés, K.; Oliván, M.; Oñate, E. Organometallics 2008, 27, 4680. (e) Esteruelas, M. A.; Fernández-Alvarez, F. J.; Oñate, E. Organometallics 2008, 27, 6236. (18) (a) Alvarez, E.; Conejero, S.; Paneque, M.; Petronilho, A.; Poveda, M. L.; Serrano, O.; Carmona, E. J. Am. Chem. Soc. 2006, 128, 13060. (b) Á lvarez, E.; Conejero, S.; Lara, P.; López, J. A.; Paneque, M.; Petronilho, A.; Poveda, M. L.; del Rı ́o, D.; Serrano, O.; Carmona, E. J. Am. Chem. Soc. 2007, 129, 14130. (c) Conejero, S.; Lara, P.; Paneque, M.; Petronilho, A.; Poveda, M. L.; Serrano, O.; Vattier, F.; Á lvarez, E.; Maya, C.; Salazar, V.; Carmona, E. Angew. Chem., Int. Ed. 2008, 47, 4380. (d) Song, G.; Li, Y.; Chen, S.; Li, X. Chem. Commun. 2008, 3558. (e) Paneque, M.; Poveda, M. L.; Vattier, F.; Alvarez, E.; Carmona, E. Chem. Commun. 2009, 5561. (f) Esteruelas, M. A.; Fernández-Alvarez, F. J.; Oliván, M.; Oñate, E. Organometallics 2009,

28, 2276. (g) Su, Y.; Song, G.; Han, K.; Li, X. J. Organomet. Chem. 2011, 696, 1640. (h) Conejero, S.; Maya, C.; Paneque, M.; Petronilho, A.; Poveda, M. L.; Vattier, F.; Á lvarez, E.; Carmona, E.; Laguna, A.; Crespo, O. Dalton Trans. 2012, 41, 14126. (19) (a) Ruiz, J.; Perandones, B. F. J. Am. Chem. Soc. 2007, 129, 9298. (b) Wang, X.; Chen, H.; Li, X. Organometallics 2007, 26, 4684. (c) Gribble, M. W., Jr.; Ellman, J. A.; Bergman, R. G. Organometallics 2008, 27, 2152. (d) Miranda-Soto, V.; Grotjahn, D. B.; DiPasquale, A. G.; Rheingold, A. L. J. Am. Chem. Soc. 2008, 130, 13200. (e) Huertos, M. A.; Pérez, J.; Riera, L.; Menéndez-Velázquez, A. J. Am. Chem. Soc. 2008, 130, 13530. (f) Huertos, M. A.; Pérez, J.; Riera, L.; Dı ́az, J.; López, R. Chem. Eur. J. 2010, 16, 8495. (g) Ruiz, J.; Perandones, B. F.; Van der Maelen, J. F.; Garcı ́a-Granda, S. Organometallics 2010, 29, 4639. (h) Song, G.; Su, Y.; Periana, R. A.; Crabtree, R. H.; Han, K.; Zhang, H.; Li, X. Angew. Chem., Int. Ed. 2010, 49, 912. (i) MirandaSoto, V.; Grotjahn, D. B.; Cooksy, A. L.; Golen, J. A.; Moore, C. E.; Rheingold, A. L. Agew. Chem. Int. Ed. 2011, 50, 631. (j) Eguillor, B.; Esteruelas, M. A.; Garcı ́a-Raboso, J.; Oliván, M.; Oñate, E.; Pastor, I. M.; Peñafiel, I.; Yus, M. Organometallics 2011, 30, 1658. (20) (a) Wiedemann, S. H.; Lewis, J. C.; Ellman, J. A.; Bergman, R. G. J. Am. Chem. Soc. 2006, 128, 2452. (b) Lewis, J. C.; Bergman, R. G.; Ellman, J. A. J. Am. Chem. Soc. 2007, 129, 5332. (c) Lewis, J. C.; Bergman, R. G.; Ellman, J. A. Acc. Chem. Res. 2008, 41, 1013. (d) Bajo, S.; Esteruelas, M. A.; López, A. M.; Oñate, E. Organometallics 2012, 31, 8618. (21) (a) Cristóbal, C.; Hernández, Y. A.; López-Serrano, J.; Paneque, M.; Petronilho, A.; Poveda, M. L.; Salazar, V.; Vattier, F.; Á lvarez, E.; Maya, C.; Carmona, E. Chem. Eur. J. 2013, 19, 4003. (b) Vattier, F.; Salazar, V.; Paneque, M.; Poveda, M. L.; Á lvarez, E. Organometallics 2014, 33, 498. (22) See for example: (a) Castarlenas, R.; Esteruelas, M. A.; Oñate, E. Organometallics 2005, 24, 4343. (b) Baya, M.; Eguillor, B.; Esteruelas, M. A.; Oliván, M.; Oñate, E. Organometallics 2007, 26, 6556. (c) Castarlenas, R.; Esteruelas, M. A.; Lalrempuia, R.; Oliván, M.; Oñ ate, E. Organometallics 2008, 27, 795. (d) Castarlenas, R.; Esteruelas, M. A.; Oñ ate, E. Organometallics 2008, 27, 3240. (e) Buil, M. L.; Cadierno, V.; Esteruelas, M. A.; Gimeno, J.; Herrero, J.; Izquierdo, S.; Oñate, E. Organometallics 2012, 31, 6861. (f) Buil, M. L.; Esteruelas, M. A.; Fernández, I.; Izquierdo, S.; Oñate, E. Organometallics 2013, 32, 2744. (23) See for example: (a) Johnson, T. J.; Albinati, A.; Koetzle, T. F.; Ricci, J.; Eisenstein, O.; Huffman, J. C.; Caulton, K. G. Inorg. Chem. 1994, 33, 4966. (b) Yandulov, D. V.; Bollinger, J. C.; Streib, W. E.; Caulton, K. G. Organometallics 2001, 20, 2040. (c) Barrio, P.; Esteruelas, M. A.; Oñate, E. Organometallics 2004, 23, 3627. (d) Baya, M.; Buil, M. L.; Esteruelas, M. A.; Oñate, E. Organometallics 2005, 24, 2030. (e) Esteruelas, M. A.; Garcı ́a-Yebra, C.; Oliván, M.; Oñate, E. Inorg. Chem. 2006, 45, 10162. (f) Esteruelas, M. A.; Hernández, Y. A.; López, A. M.; Oliván, M.; Rubio, L. Organometallics 2008, 27, 799. (g) Castro-Rodrigo, R.; Esteruelas, M. A.; López, A. M.; López, F.; Macareñas, J. L.; Oliván, M.; Oñate, E.; Saya, L.; Villarino, L. J. Am. Chem. Soc. 2010, 132, 454. (h) Castro-Rodrigo, R.; Esteruelas, M. A.; López, A. M.; López, F.; Macareñas, J. L.; Mozo, S.; Oñate, E.; Saya, L. Organometallics 2010, 29, 2372. (i) Castro-Rodrigo, R.; Esteruelas, M. A.; López, A. M.; Mozo, S.; Oñate, E. Organometallics 2010, 29, 4071. (j) Albertin, G.; Albinati, A.; Antoniutti, S.; Bortoluzzi, M.; Rizzato, S. J. Organomet. Chem. 2012, 702, 45. (k) Castro-Rodrigo, R.; Esteruelas, M. A.; López, A. M.; Oñate, E. Organometallics 2012, 31, 1991. (24) Allen, F. H.; Davies, J. E.; Galloy, J. J.; Johnson, O.; Kennard, O.; Macrae, C. F.; Mitchell, E. M.; Mitchell, G. F.; Smith, J. M.; Watson, D. G. J. Chem. Inf. Comput. Sci. 1991, 31, 187. (25) Gómez-Gallego, M.; Sierra, M. A. Chem. Rev. 2011, 111, 4857. (26) (a) Buchanan, J. M.; Stryker, J. M.; Bergman, R. G. J. Am. Chem. Soc. 1986, 108, 1537. (b) Deutsch, P. P.; Eisenberg, R. J. Am. Chem. Soc. 1990, 112, 714. (c) Hsu, G. C.; Kosar, W. P.; Jones, W. D. Organometallics 1994, 13, 385. (d) Esteruelas, M. A.; Lahoz, F. J.; Oñate, E.; Oro, L. A.; Sola, E. J. Am. Chem. Soc. 1996, 118, 89. (e) Wick, D. D.; Reynolds, K. A.; Jones, W. D. J. Am. Chem. Soc. 1999, 121, 3974. (f) Kanzelberger, M.; Singh, B.; Czerw, M.; Krogh1857


Organometallics

Article

Jespersen, K.; Goldman, A. S. J. Am. Chem. Soc. 2000, 122, 11017. (g) Northcutt, T. O.; Wick, D. D.; Vetter, A. J.; Jones, W. D. J. Am. Chem. Soc. 2001, 123, 7257. (h) Crumpton-Bregel, D. M.; Goldberg, K. I. J. Am. Chem. Soc. 2003, 125, 9442. (i) West, N. M.; Reinartz, S.; White, P. S.; Templeton, J. L. J. Am. Chem. Soc. 2006, 128, 2059. (27) (a) Foley, N. A.; Lee, J. P.; Ke, Z.; Gunnoe, T. B.; Cundari, T. R. Acc. Chem. Res. 2009, 42, 585. (b) Joslin, E. E.; McMullin, C. L.; Gunnoe, T. B.; Cundari, T. R.; Sabat, M.; Myers, W. H. Organometallics 2012, 31, 6851. (28) Blessing, R. H. Acta Crystallogr., Sect. A 1995, A51, 33. SADABS: Area-detector absorption correction; Bruker-AXS, Madison, WI, 1996. (29) SHELXTL Package v. 6.14; Bruker-AXS, Madison, WI, 2000. Sheldrick, G. M. Acta Crystallogr. Sect. A 2008, A64, 112−122.

1858


Selective meta-CâH Bond Activation of Substituted 1,3

Recommend Documents

Selective meta-CâH Bond Activation of Substituted 1,3