Synthesis of Trisubstituted Chromanes by Lewis-Base-Catalyzed Three-Component Electrophilic Thiofunctionalization of Cyclopropene with Phenols via a Formal [3+3] Annulation

A Lewis-base-catalyzed three-component electrophilic thiofunctionalization of cyclopropene with phenol is developed to furnish various trisubstituted chromanes in high trans-diasteroselectivity. This metal-free protocol is easy to scaleup, offers a unique 2,2,3-substitution pattern, and delivers chromanes with diversified core substitution patterns. The unprecedented tolerance of strong electron-withdrawing substituents at the phenol renders the protocol indispensable to access the otherwise inaccessible chromane chemical space that is important for medicinal chemistry campaigns.

Automated summary

In this study, a Lewis-base-catalyzed three-component electrophilic thiofunctionalization was developed for the synthesis of trisubstituted chromanes. This metal-free protocol offers high trans-diasteroselectivity and a unique substitution pattern, enabling access to the otherwise inaccessible chromane chemical space that is important for medicinal chemistry campaigns.