Metastable phosphorus neutral monoradical: a key intermediate in the bicyclic cage formation

摘要

A key intermediate in the formation of a bicyclic cage formed between a biradical (LCP)(2) (L = carbene) and an unsaturated substrate via a [2 + 2] cycloaddition reaction has been isolated and fully characterized including by X-ray diffraction analysis. The isolation of this intermediate proves that this cycloaddition reaction proceeds stepwise which is preferred over a concerted mechanism.