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Substrate‐Controlled Diastereoselectivity Switch in the Formation of Dihydrothieno[3,4‐ c ]coumarins via [4+1] Annulations
Author(s) -
Yu LiSiHan,
Meng ChangYu,
Wang Jing,
Gao ZhiJian,
Xie JianWu
Publication year - 2019
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201801104
Subject(s) - chemistry , annulation , steric effects , stacking , sulfur , substrate (aquarium) , acceptor , nucleophilic aromatic substitution , stereochemistry , nucleophilic substitution , photochemistry , combinatorial chemistry , medicinal chemistry , organic chemistry , catalysis , oceanography , physics , condensed matter physics , geology
An expedient and practical route for realizing a novel, substrate‐controlled diastereoselective switch strategy has been successfully developed. The [4+1] annulation of thioamides with sulfur ylides proceeded smoothly via a Michael addition triggered sequential process, and trans ‐dihydrothieno[3,4‐ c ]coumarins were obtained because of steric hindrance effects between the benzoyl group and the unit of 2 H ‐chromen‐2‐one as shown in the Newman projection. Nucleophilic substitution was observed as the key step when the sulfur ylides were replaced with acetophenones in the [4+1] annulation, and a double π,π‐stacking donor‐acceptor interaction stabilized the transition state that led to the cis ‐dihydrothieno[3,4‐ c ]coumarins. In addition, a facile chemoselective reaction was also investigated, providing a series of thieno[3,4‐ c ]coumarins.