Regioselective 1,2-Hydroamination of Conjugated Enynes for Accessing Propargylamines via Dual Photoredox/Cobalt Catalysis

The photoredox-catalyzed selective addition of N–H bonds across unactivated 1,3-enynes represents a promising and sustainable transformation, enabling efficient access to high-value-added propargylamines. Current state-of-the-art advancements via photoredox catalysis rely on the α-amino radicals as reactive intermediates, leading to several deficiencies in key aspects such as selectivity and substrate compatibility. Herein, in contrast to the conventional reaction pathway, we first depict a novel photoredox/cobalt-catalyzed regioselective synthesis of propargylamines via propargyl radical-mediated reductive radical-polar crossover followed by a nucleophilic amination of propargyl–cobalt species. Our findings will spark new ideas for developing general strategies to achieve diverse propargyl derivatives from unactivated 1,3-enynes and various nucleophiles.