A novel dual gold/photoredox-catalyzed bis-arylative cyclization of chiral homopropargyl sulfonamides with diazonium salts has been developed, allowing the facile synthesis of various enantioenriched 2,3-dihydropyrroles in generally moderate to good yields with excellent enantioselectivities under very mild conditions without using any strong oxidants. The reaction is proposed to undergo an Au/Au redox cycle promoted by visible-light photoredox catalysis.

An efficient NaBArF4-catalyzed oxidative cascade cyclization of N-propargyl ynamides has been developed, leading to a diverse range of polycyclic N-heterocycles with high diastereoselectivity and enantioselectivity.

of main observation and conclusion An efficient NaBAr F 4 -catalyzed oxidative cyclization of readily available 1,5-and 1,6-diynes has been developed. Importantly, this transition metal-free oxidative catalysis proceeds via a presumable Lewis acid-catalyzed S N 2' pathway, which is distinct from the relevant oxidative rhodium and gold catalysis. This method leads to the facile and practical construction of a diverse range of synthetically useful γand δ-lactams in mostly good to excellent yields with broad substrate scope. Scheme 1 Known knowledge and conceptual advance of this contribution Results and DiscussionWe set out to screen different conditions for this reaction by Chin.