Rh-Catalyzed Enantioselective 1,4-Addition of Silyl Boronic Esters

Significance

Silyl-containing compounds are useful building blocks due to their easy functionalization (see book below). Of particular interest is the synthesis of chiral β-silyl carbonyl derivatives. Indeed, three different strategies have been developed towards their synthesis, including C-Si bond formation (T. Hayashi, Y. Matsumoto, Y. Ito J. Am. Chem. Soc. 1988, 110, 5579-5581), C-C bond formation (T. Hayashi, R. Shintani, K. Okamoto Org. Lett. 2005, 7, 4757-4759) and C-H bond formation (B. H. Lipshutz, N. Tanaka, B. R. Taft, C.-T. Lee Org. Lett. 2006, 8, 1963-1966). In the present paper, the authors report a new approach based on the 1,4-addition of nucleophilic silyl borane, which is highly selective for C-Si bond formation.