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Organocatalytic enantioselective formal synthesis of bromopyrrole alkaloids via aza-Michael addition.

Research paper by Su-Jeong SJ Lee, Seok-Ho SH Youn, Chang-Woo CW Cho

Indexed on: 29 Sep '11Published on: 29 Sep '11Published in: Organic & Biomolecular Chemistry



Abstract

An unprecedented organocatalytic enantioselective formal synthesis of bromopyrrole alkaloid natural products is reported. An organocatalytic aza-Michael addition using pyrroles as the N-centered nucleophile is utilized as the enantioselective step to construct the nitrogen-substituted stereogenic carbon center in bromopyrrole alkaloids in good yield and excellent enantioselectivity. The aza-Michael product is converted via lactamization using a Staudinger-type reductive cyclization to the key intermediate, which was previously used in the total synthesis of bromopyrrole alkaloid natural products.