CARBENOID INSERTIONS INTO THE SILICON-HYDROGEN BOND CATALYZED BY CHIRAL COPPER (I) SCHIFF-BASE COMPLEXES

An asymmetric insertion reaction of alpha-diazoesters derived from met hyl arylacetates into the silicon-hydrogen bond of silanes was achieve d using a copper (I) catalyst associated with a chiral, C-2 symmetric Schiff base. Addition of the diazoesters 1 (1 equiv) to the Cu . Lig c omplex (R,R)-3 (0.1 equiv) in the presence of the silane reagent (1.5 equiv) at -40 degrees C yielded the corresponding insertion products 2 or 4 in good yields with varying levels of selectivity (up to 84% ee) . (C) 1998 Elsevier Science Ltd. All rights reserved.