Bromine Radical Catalysis by Energy Transfer Photosensitization
Dian‐Feng Chen, Cameron H. Chrisman, Garret M. Miyake
Abstract
We report here a mild, safe, and user-friendly bromine radical catalysis system that enables efficient [3 + 2] cycloaddition of diversely substituted vinyl- and ethynylcyclopropanes with a broad range of alkenes, including drug-like molecules and pharmaceuticals. Key to the success is the use of photosensitizing triplet-state β-fragmentation of a judiciously selected precatalyst, cinnamyl bromide, to generate bromine radicals in a controlled manner using parts per million-level photocatalyst (i.e., 4CzIPN) loading.
Topics & Concepts
BromineRadicalCycloadditionCatalysisChemistryBromidePhotochemistryVinyl bromideCombinatorial chemistryPhotoredox catalysisPhotocatalysisOrganic chemistryRadical Photochemical ReactionsCatalytic C–H Functionalization MethodsSulfur-Based Synthesis Techniques