Light-Induced and Strain-Releasing Reactions of Bicyclo[1.1.0]butanes with Alkenes as a Route to Spirocyclobutanes

A photochemical approach to biologically active spirocyclobutyl oxindoles involving a cyclization/alkylation reaction sequence of bicyclo[1.1.0]butane (BCB)-containing o-iodoanilides with alkenes is reported. A broad range of alkenes, including styrenes, vinylpyridines and dienes, can participate effectively in such sequences that provide a complement to existing means for the synthesis of functionalized spirocyclobutyl oxindoles. Certain products so-formed inhibit the growth of the SiHa, H1975, and MDA-MB-123 cancer cell lines.