OSMIUM-PROMOTED ELECTROPHILIC SUBSTITUTION OF ANISOLES - A VERSATILE NEW METHOD FOR THE INCORPORATION OF CARBON SUBSTITUENTS

A structurally and electronically diverse set of anisoles are dihapto- coordinated to the pi-base pentaammineosmium(II) and treated with a va riety of carbon electrophiles (e.g. Michael accepters, acetals). After deprotonation of a 4H-anisolium intermediate with a tertiary amine ba se, C(4)-substituted anisole complexes are isolated. The functionalize d arenes are removed from the metal center either by mild heating or t reatment with an oxidant (e.g. AgOTf, DDQ, CAN). The resulting substit uted anisoles are isolated with yields ranging from 55-95%.