COMPETITIVE GENERATION OF C-H AND C-SI BONDS BY REDUCTIVE ELIMINATION - FORMATION OF SILAMETALLACYCLES BY METALATION OF SILYL LIGANDS

Exclusive reductive elimination of methane occurs from the iridium complexes 1 and 2 on heating. This leads to the formation of new five‐membered silametallacycles by metalation at the δ position of an OEt substituent and to new four‐membered silametallacycles by orthometalation, respectively; in contrast, complex 3 eliminates both methane and Et3MeSi in a competitive reaction. The question whether CH or CSi elimination takes place in catalytic processes such as hydrosilation is thus also dependent on the nature of the substituents on the silyl ligand. LPMe3. (Figure Presented.) Copyright © 1994 by VCH Verlagsgesellschaft mbH, Germany