Stereoselective synthesis of functionalized azepines via gold and palladium relay catalysis

Abstract

We report herein a gold/palladium bimetallic relay catalytic strategy for the efficient synthesis of furan-fused azepines with moderate to high diastereoselectivities and excellent enantioselectivities. With this procedure, enynamides were activated by a gold catalyst to generate azadienes in situ, which trapped the Pd-TMM species via the asymmetric [4 + 3] cycloaddition process. Moreover, potassium nitrate mediated oxidative furan cleavage of the cycloadducts was achieved to synthesize poly-functionalized enantioenriched azepines with high efficiency under mild conditions.