A new cascade halosulfonylation of 1,7-enynes toward 3,4-dihydroquinolin-2(1H)-ones via sulfonyl radical-triggered addition/6-exo-dig cyclization

Yi-Long Zhu, Bo Jiang*, Wen-Juan Hao, Ai-Fang Wang, Jiang-Kai Qiu, Ping Wei*, Decai Wang, Guigen Li, Shu-Jiang Tu*

A new cascade three-component halosulfonylation of 1,7-enynes for efficient synthesis of densely functionalized 3,4-dihydroquinolin-2(1H)-ones has been established from readily accessible arylsulfonyl hydrazides and NIS (or NBS). The reaction pathway involves in situ-generated sulfonyl radical-triggered α,β-conjugated addition / 6-exo-dig cyclization / radical coupling sequence, resulting in continuous multiple bond-forming events including C−S, C-C and C-I (or C-Br) bonds to rapidly build up molecular complexity

Chem. Commun. 2016, 52, 1907-1910