Palladium-Catalyzed Cascade to Benzoxepins by Using Vinyl-Substituted Donor-Acceptor Cyclopropanes

A palladium-catalyzed intermolecular cascade (4+3) cyclocondensation of salicylaldehydes and vinylcyclopropanes is reported. A key feature of the reaction is the use of a phosphonate group as an acceptor moiety on the cyclopropane, exploiting its propensity to undergo olefination with aldehydes. Subsequent O-allylation enabled the formation of a range of substituted benzoxepinsWith a novel chiral ligand, the products were obtained in generally good yield and with reasonable enantioselectivity.

Automated summary

A palladium-catalyzed intermolecular cascade (4+3) cyclocondensation reaction using salicylaldehydes and vinylcyclopropanes as substrates is reported, with the utilization of a phosphonate group on the cyclopropane as an acceptor moiety. This reaction facilitated the formation of substituted benzoxepins through subsequent O-allylation, with good yield and reasonable enantioselectivity achieved using a novel chiral ligand.