Abstract
Cyclopropanes are important building blocks that are used widely in the pharmaceutical and agrochemical industries. However, synthesizing highly substituted cyclopropanes has proven to be challenging. Herein, we disclose a new strategy to prepare borylated cyclopropanes through the use of a boron-enabled cycloisomerization reaction. The method relies on the generation of a triplet biradical through an energy transfer process. Subsequent 1,2-boron shift leads to the formation of a triplet 1,3-biradical, which is poised to undergo radical recombination in concert with intersystem crossing. The generated borylated cyclopropanes are useful intermediates, as a variety of highly substituted cyclopropanes can be easily prepared.