Electrophilic Organobismuth Dication Catalyzes Carbonyl Hydrosilylation
Ramkumar Kannan, Selvakumar Balasubramaniam, Sandeep Kumar, Raju Chambenahalli, Eluvathingal D. Jemmis, Ajay Venugopal
Abstract
Abstract 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 [(Me 2 NC 6 H 4 )Bi] 2+ possessing three electrophilic sites is experimentally evidenced by the isolation of [{Me 2 NC 6 H 4 }Bi{OP(NMe 2 ) 3 } 3 ][B(3,5‐C 6 H 3 Cl 2 ) 4 ] 2 . These observations led us to generate dicationic organobismuth catalyst, [(Me 2 NC 6 H 4 )Bi(L) 3 ] 2+ (L=aldehyde/ketone), evidenced by NMR spectroscopy in solution and by single‐crystal X‐ray 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.