The first heterogeneous gold(I)‐catalyzed regiospecific hydroamination of ynamides and propiolic acid derivatives with anilines has been achieved by using a diphenylphosphine‐functionalized MCM‐41‐supported gold (I) complex and AgNTf2 as catalysts under mild conditions, yielding the corresponding (E)‐N‐arylimines and (Z)‐enamines in good to excellent yields with broad substrate scope. The new heterogeneous gold(I) complex can easily be prepared via a two‐step procedure from commercially available reagents and recovered by simple filtration of the reaction mixture. The recovered catalyst (Ph2P‐MCM‐41‐AuNTf2) can be reused at least seven times without addition of AgNTf2 as a co‐catalyst and its catalytic efficiency remains unaltered.magnified image

The first heterogeneous gold(I)‐catalyzed direct C(sp2)–C(sp) bond functionalization of arylalkynes through a nitrogenation process to amides has been achieved by using an ordered mesoporous silica (MCM‐41)‐immobilized phosphine gold(I) complex [MCM‐41‐PPh3‐AuCl] as catalyst and silver carbonate (Ag2CO3) as cocatalyst with trimethylsilyl azide (TMSN3) as a nitrogen source, yielding a variety of amides in moderate to excellent yields under mild conditions. This heterogeneous phosphine gold(I) complex shows the same turnover numbers as the homogeneous chloro(triphenylphosphine)gold(I) (Ph3PAuCl) and can easily be recovered by simple filtration of the reaction solution and recycled at least eight times without significant loss of activity, providing a novel, efficient, practical and economic method for the synthesis of amides from alkynes.magnified image

A novel and efficient heterogeneous gold(I)-catalyzed highly regio-and chemoselective oxidative ring expansion of 2-alkynyl-1,2-dihydropyridines or -quinolines has been developed that proceeds smoothly through exclusive 1,2-migration of a vinyl or phenyl group with pyridine N-oxide as oxidant under mild conditions. The reaction provides a general and practical method for the synthesis of a wide variety of azepine derivatives with high atom-economy, high to excellent yield, broad functional group tolerance, and recyclability of the gold(I) catalyst. The present method is an attractive alternative to construct functionalized azepines or benzazepines.

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