Highly Diastereoselective Synthesis of Methylenecyclobutanes by Merging Boron‐Homologation and Boron‐Allylation Strategies

Abstract

A highly diastereoselective synthesis of methylenecyclobutanes possessing a quaternary stereocenter is reported, in which boron homologation of an easily-generated cyclobutenylmetal species is performed, followed by an allylation reaction. Combining three steps in a one-pot process further optimized the method, which afforded the expected adducts in excellent yields and stereoselectivity, starting from commercially available 4-bromobutyne.