SELECTIVE ACTIVATION OF CARBON-CARBON BONDS NEXT TO A CARBONYL GROUP

ORGANOMETALLIC complexes are used to effect a wide range of catalytic transformations in organic synthesis, such as the activation of C-H bo nds(1,2). Carbon-carbon bonds, however, are generally unreactive towar ds transition metals under homogeneous conditions. C-C bond activation by a process of oxidative addition to soluble transition-metal comple xes has been limited mostly to stoichiometric (not catalytic) reaction s(1,3-7,18), to highly strained substrates such as cyclopropane and cu bane(1,8-11) or to chelating ketones(19). Here we present a synthetica lly useful process of selective C-C bond activation in which the C-C b ond adjacent to a carbonyl group is opened by insertion of a soluble r hodium(I) complex. The resulting organometallic intermediate can be tr ansformed to a variety of products in a way that regenerates the rhodi um complex. We anticipate that this catalytic scheme will have conside rable utility in organic synthesis.