Electrophilic Organobismuth Dication Catalyzes Carbonyl Hydrosilylation.

Bismuth compounds are gaining importance as potential alternatives to transition-metal complexes and electron deficient lighter p-block compounds in homogeneous catalysis. Computational analysis on the two-coordinate [(Me2NC6H4)Bi](2+) possessing three electrophilic sites is experimentally evidenced by the isolation of [{Me2NC6H4}Bi{OP(NMe2)(3)}(3)][B(3,5-C6H3Cl2)(4)](2). These observations led us to generate dicationic organobismuth catalyst, [(Me2NC6H4)Bi(L)(3)](2+) (L = aldehyde/ketone), evidenced by NMR spectroscopy in solution and by single-crystal Xray diffraction in the solid state. It efficiently catalyzes hydrosilylation of aldehydes and ketones resulting in silyl ethers as the only products in high yields. Our investigations support a carbonyl activation mechanism at the bismuth center followed by Si-H addition.