Stereoselective Synthesis of Cyclobutanes by Contraction of Pyrrolidines

Here we report a contractive synthesis of multisubstituted cyclobutanes containing multiple stereocenters from readily accessible pyrrolidines using iodonitrene chemistry. Mediated by a nitrogen extrusion process, the stereospecific synthesis of cyclobutanes involves a radical pathway. Unprecedented unsymmetrical spirocyclobutanes were prepared successfully, and a concise, formal synthesis of the cytotoxic natural product piperarborenine B is reported.

Automated summary

This report presents a contractive synthesis of multisubstituted cyclobutanes from readily accessible pyrrolidines using iodonitrene chemistry. The stereospecific synthesis of cyclobutanes through a radical pathway mediated by a nitrogen extrusion process is described, resulting in the successful preparation of unprecedented unsymmetrical spirocyclobutanes, as well as a concise, formal synthesis of the cytotoxic natural product Piperarborenine B.