Rapid Mechanochemical Ring-Opening and 1,3-Bisfunctionalization of Donor–Acceptor Cyclopropanes: Regioselective C(sp²)–H Alkylation of Coumaran and Chromane

Regioselective alkylation of 2,3-dihydrobenzofuran (coumaran) and chromane was accomplished through the ring-opening of donor-acceptor cyclopropanes (DACs) under mechanochemical conditions. The developed mechanochemical protocol efficiently promotes the ring-opening of DACs. Importantly, it enabled the first mechanochemical 1,3-bisfunctionalization of DACs using a range of electrophiles, furnishing the target products in high yields and significantly reducing reaction times.