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Published on: May 26, 2019
Mechanistic Studies on Bromocyclization of Unsaturated Thioester by Density Functional Theory and Experiment
Rinako Saegusa1, Miari Kurihara1, Hiroki Shigehisa1
1Faculty of Pharmacy, Musashino University, 1-1-20 Shinmachi Nishitokyo, Tokyo 202-8585, Japan.
Abstract:
Using sulfur-containing nucleophiles in halocyclization has been underexplored notwithstanding their potential to generate novel S-heterocycles and despite the extensive exploration of oxygen, nitrogen, and carbon nucleophiles. In this study, we focused on the bromocyclization of alkenoic thioesters with N-bromoacetamide, which leads to the formation of cyclic bromosulfides. Investigation into the mechanistic pathways of these reactions revealed that the sulfur atom behaves as a nucleophile, leading to S-acetylsulfonium intermediates. HBr and Br2 played significant roles in these transformations.
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