Substrate‐Controlled Diastereoselectivity Switch in the Formation of Dihydrothieno[3,4‐c]coumarins via [4+1] Annulations

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...

Full description

Saved in:
Bibliographic Details
Published in:Advanced synthesis & catalysis 2019-02, Vol.361 (3), p.526-534
Main Authors: Yu, Li‐Si‐Han, Meng, Chang‐Yu, Wang, Jing, Gao, Zhi‐Jian, Xie, Jian‐Wu
Format: Article
Language:English
Subjects:
[4+1] Annulations
Chemical reactions
Coumarins
Dihydrothieno[3,4-c]coumarins
Dihydrothiophenes
Organic chemistry
Stereoselectivity
Steric hindrance
Substitution reactions
Substrates
Sulfur
Thioamides
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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 2H‐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.
ISSN:1615-4150
1615-4169
DOI:10.1002/adsc.201801104