Transition-metal-free chemoselective catalytic hydrosilylation of tertiary amides to hemiaminals by Me2SiH2 generated from controllable disproportionation of 1,1,3,3-tetramethyldisiloxane

Chemoselective hydrosilylation of amides to hemiaminals offers an effective route to aldehydes and nitrogenous skeletons. We herein present a (KOBu)-Bu-t-catalyzed hydrosilylation of various aromatic and aliphatic tertiary amides with TMDS affording aldehydes and/or functional amines with excellent chemoselectivities (up to 30 : 1) under mild and convenient conditions. Mechanistic investigations using in situ(1)H/Si-29 NMR and FTIR show the highly selective hemiaminal formation and reveal a rapid disproportionation of TMDS controlled by amides and (KOBu)-Bu-t. Moreover, the product of disproportionation, Me2SiH2, is confirmed as the distinctive reductant for the precise chemoselectivity control of hydrosilylation.