One‐Pot Controlled Reduction of Conjugated Amides by Sequential Double Hydrosilylation Catalyzed by an Iridium(III) Metallacycle

Abstract

A single and accessible cationic iridium III metallacycle effectively catalyzes the one-pot sequential double hydrosilylation of challenging α,-unsaturated secondary and tertiary amides to afford, in a controlled and straightforward way, the corresponding reduced products, namely, the related secondary and tertiary amides and amines. The catalytic hydrosilylations of the conjugated amides described herein proceeded in good yields and high chemoselectivities. The critical silyl enolate, in [a] Y.

Fate of Cobaltacycles in Cp*Co-Mediated C–H Bond Functionalization Catalysis: Cobaltacycles May Collapse upon Oxidation via Co(IV) Species

“…as a halido ligand “remover”, in transition-metal-mediated homogeneous catalysis. For instance, hydrosilylation catalysis that is otherwise ineffective with Cp*-bound chloridoiridacycles can be triggered if a [Ph 3 C]­[BArF 24 ] salt is added to the reaction mixture, seemingly acting as a chloride scavenger …”

Cyclometallated complexes as catalysts for C–H activation and functionalization

“…37 The recent years will thus certainly be marked by the development of new metallacyclic catalytic systems for advanced direct functionalization reactions. The potential of the stable and electron-rich cyclometallated catalysts goes far beyond the C-H activation and such modern complexes have clearly opened new perspectives in others fields of homogeneous catalysis for example hydrosilylations, 38 asymmetric hydrogenations 39 and imines synthesis 40 without forgetting the key role of metallacyclic species in photoredox catalysis. 41…”