J. Am. Chem. SOC.1988, 110, 2712-2774
2772
34496-58-7; pdinitrobenzene radical anion, 34505-33-4; *dinitrobenzene radical anion, 34505-38-9; p-nitrobenzaldehyde radical anion, 345 1233-9; m-nitrobenzaldehyde radical anion, 40951-85-7; 1-chloro-4-nitrobenzene radical anion, 34473-09-1; 5-nitro-m-xylene radical anion, 39933-64-7; 3-nitro-o-xylene radical anion, 83-41-0; 4-cyano-N-benzyl-
pyridinium radical, 113249-25-5; 4-cyano-N-methylpyridiniumradical, 64365-84-0; 4-carbethoxy-N-benzylpyridiniumradical, 76036-35-6; 4carbethoxy-N-methylpyridinium radical, 75302-27- 1; 4-amido-Nbenzylpyridinium radical, 1 13249-26-6; 4-amido-N-methylpyridinium radical, 113249-24-4.
Insertion of Two CO Moieties into an Alkene Double Bond To Form a RCH =C(O)C( 0)=CHR2- Unit via Organosamarium Activation’ William J. Evans* and Donald I(. Drummond Contribution from the Department of Chemistry, University of California, Iruine, Irvine. California 9271 7. Received May 1 1 , 1987
Abstract: RCH=CHR ( R = 2-pyridyl) reacts with (C5Me5)2Sm(THF)2to form a red complex, which reacts with CO at 80 psi in toluene to form [(C5Me5)?Sm]2[p-q4-RCH..-C(0)C(O)4HR] (1) in 90% yield. 1 cocrystallizes with 2 molecules of toluene in space group C 2 / m with u = 15.818 (2) A, b =I 14.060 (2) A, c = 15.353 (2) A, B = 111.480 (12)O, and 2 = 2 for Dcalcd= 1.32 g ~ m - ~Least-squares . refinement on the basis of 2526 observed reflections led to a final R value of 0.045. The two (C5Me5)$m units are bridged by a tetradentate bisenolate ligand, RCH=C(O)C(O)=CHR*-, such that each S m is coordinated to one oxygen and the nitrogen atom of the pyridyl group closest to that oxygen. The Sm-0, Sm-N, and average Sm-C(ring) distances are 2.191 (6), 2.473 (7), and 2.71 (1) A, respectively.
T h e divalent organosamarium complex (C5Me5)2Sm(THF)22 has proven t o have a remarkable reductive chemistry with unsaturated substrates such as C S , 3 * 4R=R,&’ and RNNRe8s9 This powerful Sm(I1) reagent can induce facile multiple-bond cleavage and reorganization to provide unusual transformations of multiply bonded species. Three examples are shown in eq 1-3. If C=C double bonds could also be transformed in 4(C5Me5)2Sm(THF)2+ 6CO [[(C5Me5)2Sm]2[p-q3-02CC=C=O](THF)]2 + 6THF (1)3
-
2(C5Me5)2Sm(THF)2
+
C6H,CECC6H5 (C,Me,
+
-
2C0
Table I. Crystal Data and Summary of Data Collection and Structure Refinement for
(C5MeS),Sm[p-~4-(CsH4N)CH=C(0)C(O)=CH(C5H4N)]Sm(CSM~J)~.~C~H~ formula mol wt space gP 4A
b, A c, 8,
P, deg
v,A’
z
),S m 0
g/cm3 temp, “ C h(Mo Ka),A g, cm-I min-max transmissn coeff type of scan scan width, deg scan speed, deg/min bkgd counting data collecn range, deg total no. of unique data no. of unique data with I? 341) no. of parameters R(F) Doled.
A
OSm(C,Me,+ 2(C5Me5)2Sm(THF)2
+
C6H5N=NC6H5
4- 2 C 0
-
C6H5
I
c6H5
(1) Reported in part at the 2nd International Conference on the Chemistry and Technology of the Lanthanides and Actinides, Lisbon, Portugal, April 1987, L(I1)I. (2) Evans, W. J.; Grate, J. W.; Choi, H. W.;Bloom, I.; Hunter, W. E.; Atwood, J. L. J. Am. Chem. Soc. 1985,107,941-946. (3) Evans, W. J.; Grate, J. W.; Hughes, L. A.; Zhang, H.; Atwood, J. L. J. Am. Chem. Sw.1985, 107, 3728-3730. (4) Evans, W. J.; Hughes, L. A.; Drummond, D. K.; Zhang, H.; Atwood, J. L. J. Am. Chem. Soc. 1986, 108, 1722-1723. (5) Evans, W. J.; Bloom, I.; Hunter, W. E.; Atwood, J. L. J. Am. Chem. SOC.1983, 105, 1401-1403. (6) Evans, W. J. Polyhedron 1987, 6, 803-835. (7) Evans, W. J. In High Energy Processes in Organometallic Chemistry; Suslick, K . S., Ed.; ACS Symposium Series 333; American Chemical Society: Washington, DC, 1987; pp 278-289. (8) Evans, W. J.; Drummond, D. K.;Bott, S. G.; Atwood, J. L. Organometallics 1986, 5, 2389-2391. (9) Evans, W. J.; Drummond, D. K. J. Am. Chem. Soc. 1986, 108, 7440-744 1.
RdF) GOF max A/u in final cycle
Sm2C68H86N202
1264.15 C2/m 15.818 (2) 14.060 (2) 15.353 (2) 111.480 (12) 3177 2 1.32 24 0.71 073; graphite monochromator 18.8 0.339-0.449 8-28 -1.2 in 28 from K a l to +1.2 from Ka2 3 evaluated from a 96-step peak profile 3-50 2955 2526 187 0.045 0.059 1.84 0.39
unusual ways by ( C 5 M e 5 ) 2 S m ( T H F ) z , then this organosamarium(I1) approach to multiple-bond functionalization would apply to an even wider range of substrates. We report here the samarium-mediated functionalization of a C=C bond in which complete cleavage of the double-bond and double CO insertion is observed.
Experimental Section The complexes described below are extremely air- and moisture-sensitive. Therefore, both the syntheses and subsequent manipulations of these compounds were conducted under nitrogen with rigorous exclusion of air and water by Schlenk, vacuum-line, and glovebox techniques. The preparation of (C5MeS)2Sm(THF)2 and the methods for drying solvents
0002-7863/88/15 IO-2772%01.50/0 0 1988 American Chemical Society
CO Insertion via Organosamarium Activation
J. Am. Chem. SOC.,Vol. 110, No. 9, 1988 2113
and taking physical measurements have been described previously.2 1,2-Di-2-pyridylethene(Aldrich) was degassed at room temperature. CO (Liquid Carbonic, 99.99%) was used as received. [(CSMes)2Sm]~p-q4-(NC5H4)CH==€(O)C(O)=CH(NC5H4)]. 1,2Di-2-pyridylethene, (NCSH4)CH=CH(NC5H4)(40 mg, 0.221 mmol), in 4 mL of toluene was slowly added to (CSMes)2Sm(THF)2 (250 mg, I 7' ," , 0.442 mmol) in 10 mL of toluene to form a red solution. The solution was placed in a 3-oz Fisher-Porter aerosol reaction vessel and pressurized with CO to 80 psi. After 24 h, the resulting yellow-orange solution was depressurized, concentrated to about half-volume, and cooled to -34 "C. Yellow-orange crystals of 1 (180 mg, 65%) were obtained. The 'H NMR spectrum of the bulk reaction mixture indicated that 1 was the major product (90% yield). Analytical, NMR, and IR data were obtained on Figure 1. ORTEP plot of (C5MeS)2Sm[p-?4-(C5H4N)CH=C(0)C(O)= samples of crystals that were crushed to a powder and dried under vacCH(CSH4N)]Sm(CSMe5)2. Thermal ellipsoids are shown at 30% probuum. Anal. Calcd for [(C5Me5)2Sm]2(C14H10N202): Sm, 27.8. Found: ability for clarity. Atoms without superscript labels are related to atoms Sm, 27.0. 'H NMR (C4D80): 6 5.48 (s, 1 H), 5.09 (t, 1 H), 4.97 (d, with superscript 2 by a C2 axis and to atoms with superscript 4 by a 1 H), 1.52 (s, 30 H, C5MeS). I3C NMR (C4DsO): 6 201.1 (s), 140.0 mirror plane. Superscript 3 atoms are related to superscript 2 atoms by (s), 121.3 (d, JcH = 164 Hz), 119.4 (s, CSMes),112.2 (d, JcH = 166 Hz), a mirror plane. 103.2 (d, J c H = 153 Hz), 18.7 (q, JCH = 125 Hz, CsMes). IR (KBr): 2960-2850 s, 2730 w, 1600 m, 1570 m, 1475 s, 1455 s, 1430 s, 1380 s, 1 2 0 5 ~ , 1 1 5 5 m , 1 1 1 5 m , 1 0 2 0 ~ , 9 9 5 m , 8 6 5 m , 8 0 0 m , 7 5 5 ~ , 7 4 0 m , Table 11. Interatomic Distances [A) and Andes fdee) . -, for 1 730 m cm-I. Sm(1)-O(1) 2.191 (6) O(1)-Sm(1)-N(1) 76.5 (2) X-ray Data Collection, Structure Solution, and Refinement for Sm(1)-N(l) 2.473 (7) C(1)-O(1)-Sm(1) 138.3 (6) [(C5MeS)2Sm]2[rc-q4:(NC5H4)CH--C(O)C(O)=CH(NC5H4)].2C,H,. Sm(l)-C( 10) 2.678 (8) 118.0 (8) C(3)-N(l)-C(7) General data collection and reduction procedures have been described 128.8 (6) Sm(1)-C(l1) 2.699 (8) C(3)-N(I)-Sm(l) A single crystal measuring 0.40 mm X 0.50 mm X 0.60 113.2 (6) Sm( 1)-C( 14) 2.726 (8) C(7)-N(l)-Sm(l) mm was sealed under nitrogen in a glass capillary and mounted on a 125.0 (8) 2.728 (8) O(l)-C(l)-C(2) S(I)-C(12) Nicolet R3m/V diffractometer. Lattice parameters were determined 115.7 ( I O ) O(1)-C(1)-C(1) Sm(1)-C( 13) 2.735 (8) from 25 computer-centered reflections. Data were collected by the 8-28 .299 (10) C(2)-C(l)-C( 1) 119.3 (10) O( 1)-C( 1) scan technique in bisecting geometry. The p factor in the expressioni2 129.1 (7) .343 (11) C( 1)-c(2)-c(3) N(l)-C(3) for the standard deviation of the observed intensities was given a value 118.2 (8) ,351 (12) N ( l)-C(3)-C(4) N(l)-C(7) of 0.05. Crystal and data collection parameters are given in Table I. 122.3 (8) ,355 (12) N ( l)-C(3)-C(2) C( 1 ) 4 3 2 ) During the data collection, the intensities of three standard reflections 119.5 (8) ,488 (17) C(4)-C(3)-C(2) C(l)-C(I) measured every 100 reflections exhibited only random fluctuations within 120.7 (IO) ,436 (12) C(5)-C(4)-C(3) C(2)-C(3) f 3 % . An empirical absorption correction was applied. Only one sys,429 (13) C(6)-C( 5)-C(4) 119.8 (9) C(3)-C(4) tematic absence ( h k l , h + k odd) established the space group as C2 or .361 (16) C(5)-C(6)-C(7) 118.3 (10) C(4)-C(5) C2/m. Solution and refinement of the structure showed C2/m to be the .337 (17) N( l)-C(7)-C(6) 124.9 (10) C(5)-C(6) correct choice. Refinement was also tried in space group ct but was not .352 (14) C(ll)-C(lO)-C(l4) 107.4 (8) C(6)-C(7) successful.i3 ,367 (15) C(l 1)-C( IO)-C(16) C(10)-C(11) 126.0 (16) MITHRILI' and difference Fourier techniques were used to locate all C( 10)-C( 14) 1.418 (14) C( 14)-C( 10)-C( 16) 126.6 (16) non-hydrogen atoms. All non-hydrogen atoms were refined with anisoC( 10)-C( 16) 1.555 (14) C(12)-C(l l)-C(lO) 109.4 (9) tropic temperature factors by full-matrix least-squares methods. Only C(lI)-C(12) 1.295 (14) C( 12)-C( 11)-C( 15) 124.3 (17) the hydrogen atoms of the (NCsH4)CHC(0)C(O)CH(NC5H4)2-unit 125.6 (17) C( 1 1)-C( 15) 1.541 (15) C(lO)-C(ll)-C(l5) were included with their idealized positions (C-H = 0.95 A). Atomic 110.1 (8) 1.349 ( 1 3) C(1 l)-C(12)-C(l3) C(12)-C(13) scattering factors were taken from ref 15. A final difference map C( 12)-C( 17) 1.545 (15) C( 11)-C( 12)-C( 17) 123.8 (14) contained no recognizable features; its largest peak was of height 0.92 1.385 (16) C( 13)-C( 12)-C( 17) 126.0 (14) C(13)-C(14) e A-3. Fractional coordinates are given in the supplementary material. 109.0 (8) C( 13)-C( 18) 1.535 (14) C(12)-C(13)-C(14) 128.1 (14) C( 14)-C( 19) 1.530 (14) C( 12)-C(13)-C(18) Results and Discussion 122.7 (14) C(14)-C(13)-C(18) C(20)-C( 2 1) 1.34 (2) Given the success observed in (CSMeS)2Sm(THF)2-based C(20)-C(24) C( 13)-C( 14)-C( IO) 104.2 (8) 1.37 (3) transformations of the diphenyl-substituted substrates, C 6 H S m 127.3 (15) 1.36 (3) C(I3)-C(14)-C(19) C(21)-C(22) CC6Hs4and C6HSN=NC6HS9(eq 2 and 3), the diphenyl-subC( 10)-C( 14)-C( 19) 128.4 (15) 1.33 (2) C(22)-C(23) C(2 l)-C(2O)-C(2 1) 123 (2) stituted alkene C6HSCH=CHC6HSseemed to be a logical subC(21)-C(20)-C(24) 119 (1) strate with which to investigate C=C bond reactivity. Although C(20)-C(21)-C(32) 115 (2) (CSMes)2Sm(THF), reacts with trans-C6HSCH=CHC6HS16in 128 (2) C(23)-C(22)-C(21) the presence of CO, definitive characterization of the organo\
metallic products by X-ray crystallography has not yet been obtained. A nitrogen-substituted analogue of stilbene, namely 1,2-di-2-pyridylethene, (NCSH4)CH=CH(NCSH4),was chosen as an alternative substrate since the extra coordination possible via the nitrogen atoms could lead to a more readily definable, crystalline product. Synthesis. Addition of a toluene solution of 1,2-di-2-pyridylethene to (CSMe5)2Sm(THF)2 in toluene forms a red solution, which reacts with C O a t 80 psi. After 24 h, the solution had the (10) Sams, D. B.; Doedens, R. J. Inorg. Chem. 1979, 18, 153-156. (1 1) UCLA Crystallographic Computing Package, University of California, Los Angela, 1981. Strouse, C., personal communication to R. J. Doedens. (12) Corfield, P. W. R.; Doedens, R. J.; Ibers, J. A. Inorg. Chem. 1967, 6, 197-204.
(13) Cf.: Marsh, R. E. Acta Crystallogr.,Sect. B Struct. Sci. 1986,842, 193-1 98. (14) Gilmore, C. J. MITHRIL, A Computer Program for the Automatic Solution of Crystal Structures from X-ray Data; University of Glasgow: Glasgow, Scotland, 1984. (1 5 ) International Tables for X-ray Crystallography; Kynoch: Birmingham, England, 1974; Vol. IV, p 72. (16) (C5Me5),Sm(THF), isomerizes cis-stilbene to the trans isomer.6
,
yellow-orange color characteristic of a Sm3+ organometallic complex,6 and 'H N M R spectroscopy showed a single primary product had been formed. Crystals suitable for X-ray crystallography were obtained, and the product of the reaction was identified as [(CSMeS)2Sm]2[p-~4-iNCsH4)CH=C(0)C(O)= CH(NC
