TBAT-Catalyzed Deoxygenative Reduction of Tertiary Amides to Amines.

A simple, mild, metal-free catalytic protocol is developed to convert amides to amines. This protocol uses a stable tetrabutylammonium difluorotriphenylsilicate in combination with silanes that generates a highly reactive hydrosilicate species, which enables the reduction of a broad range of amides to amines in moderate to good yields. The attractive features of this protocol include operational simplicity, safety, short reaction times, room temperature reaction, broad substrate scope, and amenable to scale up.

Visible-Light-Promoted Dual Photoredox/Nickel-Catalyzed Chemoselective Reduction of Secondary and Tertiary Amides with Hydrosilanes in the Presence of an Ester.

We report a one-step procedure to selectively reduce secondary and tert-amides to their corresponding amine derivatives in the presence of an ester. This was achieved via the synergistic combination of a photoredox, a nickel catalytic system, and phenyl silane as a reductant in the presence of blue light-emitting diode light (455 nm) at room temperature. Further, this mild light-promoted dual metallaphotoredox catalytic system was also successful in selectively reducing a lactam to the cyclic amines, without affecting the ester moiety present in the molecules.

AlCl3-Mediated CHF2 Transfer and Cyclocondensation of Difluoromethoxy Functionalized o-Phenylenediamines to Access N-Substituted Benzimidazoles.

Herein, we report for the first time a transition-metal-free frustrated Lewis pair (FLP) catalyzed CHF2 group migration from an oxygen atom to the neighboring nitrogen atom, which led to the synthesis of N-substituted benzimidazoles at room temperature with excellent yields, broad functional group tolerance, and a short reaction time. The oxygen-attached difluoromethane acted as a C1 source in the synthesis of N-substituted benzimidazoles in the presence of AlCl3 by cleaving one C-O bond and two C-F bonds, resulting in formation of two new C-N bonds.