Recent topics of iridium-catalyzed hydrosilylation of tertiary amides to silylhemiaminals

Iridium-catalyzed hydrosilylation of amides with 1,1,3,3-tetramethyldisiloxane (TMDS) allows access to silylhemiaminals, which are often spontaneously converted to aldenamines. Iridium(I) phosphine species generated from IrCl(CO)(PPh3)(2), IrCl(PPh3)(3), or a mixture of [IrCl(COD)](2) and phosphorous ligands showed high catalytic activity for this reaction protocol, which demonstrated remarkable compatibility toward other reducible functional groups such as ketone and ester groups. This reaction enables the synthesis of pi-conjugate enamines having hole-transport properties by appropriate selection of the iridium catalyst. Easy access to silyl hemiaminals and enamined stimulated other research groups to discover new reductive C-C bond-forming reactions to transform amides to amine derivatives, which can be applied to the synthesis of complex alkaloid molecules. (C) 2019 Published by Elsevier Ltd.