Rhodium(I)-mono- und -diazadienkomplexe, synthese, spektroskopische charakterisierung, oxidative additionsreaktionen und einsatz in der homogenen katalyse zur hydrosilylierung

Abstract

The reaction of [Rh(CO) 2Cl) 2 with di- and monoazadienes gives planar, four-coordinated rhodium(I) complexes Rh(CO)Cl(DAD) (III) and Rh(CO)Cl(MAD) 2 (V), respectively, which catalyse the hydrosilylation of alkenes and alkynes. In a stereoselective cis-addition symmetric internal alkynes give the corresponding silyl alkenes, while the catalytic addition of silane to terminal alkynes leads to the 2-silyl and cis- and trans-1-silyl-alkenes; their ratio depends on the controlling ligand and on the reaction conditions. With a stoichiometric amount of the silane the complexes III react under oxidative addition to give the rhodium(III) complexes Rh(H)(SiR 3)(DAD)Cl (VI), which also catalyse the hydrosilylation.