Rh-Catalyzed [3+2] Cycloaddition of 1-Sulfonyl-1,2,3-triazoles: Access to the Framework of Aspidosperma and Kopsia Indole Alkaloids

A Rh(II)-catalyzed dearomative intramolecular [3 + 2] dipolar cycloaddition involving the indolic C2-C3 carbon-carbon double bond has been developed. The reaction was launched from the triazole moiety within the substrate and proceeded efficiently under mild conditions., A wide range of functional groups could be tolerated. These features render the current reaction a highly useful tool for the synthesis of polycyclic indole alkaloids, as showcased by a rapid assembly of the core structure of Aspidosperma and the related alkaloids.National Natural Science Foundation of China [21302078, 21572089, 21290183]; Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT) [IRT_15R28]; FRFCU [lzujbky-2016-ct02, lzujbky-2016-52]; SRFDP [20130211120020]SCI(E)ARTICLEliyun@lzu.edu.cn; zhaihb@pkusz.edu.cn164076-40791