10074
J. Org. Chem. 1998, 63, 10074-10076
First Nickel-Catalyzed 1,4-Conjugate Additions to r,β-Unsaturated Systems Using Triorganoindium Compounds
Scheme 1
Ignacio Pe´rez,† Jose´ Pe´rez Sestelo,† Miguel A. Maestro,† Antonio Mourin˜o,‡ and Luis A. Sarandeses*,† Departamento de Quı´mica Fundamental e Industrial, Universidade da Corun˜ a, E-15071 A Corun˜ a, Spain, and Departamento de Quı´mica Orga´ nica, Universidade de Santiago de Compostela, E-15706 Santiago de Compostela, Spain
Table 1. Effects of Nickel Complexes on the Conjugate Addition of n-Bu3In to 2-Cyclohexen-1-one yield (%)a
Received September 8, 1998
Introduction Organometallic 1,4-conjugate addition to enones is an important means of C-C bond formation in organic synthesis.1 This reaction was once limited to organocopper chemistry, but now it has been known to be possible with other organometallic compounds through catalysis by metals, nickel especially.2 In continuance of our research on new applications of organometallics to the 1,4-conjugate addition reaction and others,3 we report herein a novel, efficient nickel-catalyzed conjugate addition of triorganoindium compounds to R,β-unsaturated systems. Indium has drawn the attention of chemists for many years due to its position in the periodic table, in the same group as boron and aluminum and close to zinc and tin, and to its interesting chemical properties.4 Nevertheless, the synthetic applications of organoindium compounds are few, are relatively recent,4 and are limited to (i) the allylation of carbonyls and triple bonds under classical5 or Barbier conditions (mostly in aqueous media)6 and (ii) Reformatsky-type reactions.7 Alkyl organoindium species, †
Universidade da Corun˜a. Universidade de Santiago de Compostela. (1) (a) Perlmutter, P. Conjugate Addition Reactions in Organic Synthesis; Pergamon: Oxford, U.K., 1992. (b) Kozlowski, J. A. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Eds.; Pergamon: Oxford, U.K., 1992; Vol. 4, p 169. (2) (a) Petrier, C.; de Souza Barbosa, J. C.; Dupuy, C.; Luche, J.-L. J. Org. Chem. 1985, 50, 5761. (b) Eshelby, J. J.; Crowley, P. J.; Parsons, P. J. Synlett 1993, 279. (c) Schwartz, J.; Carr, D. B.; Hansen, R. T.; Dayrit, F. M. J. Org. Chem. 1980, 45, 3053. (d) Westermann, J.; Nickisch, K. Angew. Chem., Int. Ed. Engl. 1993, 32, 1368. (e) Flemming, S.; Kabbara, J.; Nickisch, K.; Neh, H.; Westermann, J. Tetrahedron Lett. 1994, 35, 6075. (f) Flemming, S.; Kabbara, J.; Nickisch, K.; Neh, H.; Westermann, J. Synthesis 1995, 317. (g) Westermann, J.; Imbery, U.; Nguyen, A. T.; Nickisch, K. Eur. J. Inorg. Chem. 1998, 295. (3) (a) Dupuy, C.; Petrier, C.; Sarandeses, L. A.; Luche, J.-L. Synth. Commun. 1991, 21, 643. (b) Sarandeses, L. A.; Mourin˜o, A. Luche, J-L. J. Chem. Soc., Chem. Commun. 1992, 798. (c) Pe´rez-Sestelo, J.; Mascaren˜as, J. L.; Castedo, L.; Mourin˜o, A. J. Org. Chem. 1993, 58, 118. (4) For a review of the applications of indium in organic synthesis, see: Cintas, P. Synlett 1995, 1087. (5) (a) Araki, S.; Ito, H.; Butsugan, Y. J. Org. Chem. 1988, 53, 1831. (b) Araki, S.; Shimizu, T.; Johar, P. S.; Jin, S.-J.; Butsugan, Y. J. Org. Chem. 1991, 56, 2538. (c) Araki, S.; Imai, A.; Shimizu, K.; Yamada, M.; Mori, A.; Butsugan, Y. J. Org. Chem. 1995, 60, 1841. (6) (a) Li, C.-J.; Chan, T.-H. Tetrahedron Lett. 1991, 32, 7017. (b) Kim, E.; Gordon, D. M.; Schmid, W.; Whitesides, G. M. J. Org. Chem. 1993, 58, 5500. (c) Chan, T.-H.; Lee, M.-C. J. Org. Chem. 1995, 60, 4228. (d) Maguire, R. J.; Mulzer, J.; Bats, J. W. J. Org. Chem. 1996, 61, 6936. (e) Paquette, L. A.; Mitzel, T. M. J. Org. Chem. 1996, 61, 8799. (f) Yi, X.-H.; Meng, Y.; Li, C.-J. Chem. Commun. 1998, 449. ‡
e
entry no.
catalyst
1 2 3 4 5 6 7
no catalyst Ni(PPh3)2Cl2 Ni(acac)2 Ni(PPh3)2Cl2/DIBALHc Ni(acac)2/DIBALHd Ni(PPh3)4e Ni(COD)2f
2b 13 30 16 15 80
a Isolated yields. b R ) n-Bu. c Reference 10a. Reference 11. f Reference 12.
d
3b
1
10
80 80 60 75 95 82
Reference 10b.
as far as we know, have only been used in cross-coupling reactions with chloroalkenes.8 Results and Discussion The 1,4-conjugate addition reaction of organoindium compounds has previously been studied by Araki et al., who reported that triorganoindium compounds are unreactive toward enones but that some tetraalkylindates add in a 1,4-fashion in moderate yields.9 In our experiments the reactivity of triorganoindium compounds with enones was also low, giving
