Visible‐Light‐Mediated Heterocycle Functionalization via Geometrically Interrupted [2+2] Cycloaddition
作者:Mihai V. Popescu、Aroonroj Mekereeya、Juan V. Alegre‐Requena、Robert S. Paton、Martin D. Smith
DOI:10.1002/anie.202009704
日期:2020.12.14
cyclization in the triplet excited state to yield a 1,4‐diradical; intersystem crossing leads preferentially to the closed shell singlet zwitterion. This is geometrically restricted from undergoing recombination to yield a cyclobutane by the planarity of the amide substituent. A prototropic shift leads to the observed bicyclic products in what can be viewed as an interrupted [2+2] cycloaddition.