Capture–Collapse Heterocyclization: 1,3-Diazepanes by C–N Reductive Elimination from Rhodacyclopentanones

Abstract

Rhodacyclopentanones derived from carbonylative C-C activation of cyclopropyl ureas can be "captured" by pendant nucleophiles prior to "collapse" to 1,3-diazepanes. The choice of N-substituent on the cyclopropane unit controls the oxidation level of the product, such that C4-C5 unsaturated or saturated systems can be accessed selectively.