Reactions of NHC‐Boranes with Dibenzoyl Peroxide and Benzoic Acid
Daniel A. Bolt, Dennis P. Curran
Abstract
Abstract NHC‐boranes (NHC−BH 3 ) react slowly under thermal conditions with dibenzoyl peroxide to make mixtures of NHC‐boryl mono‐ and dibenzoates [NHC−BH 2 OBz and NHC−BH(OBz) 2 ]. Reactions are much faster under radical conditions with AIBN of TBHN as initiators. The TBHN method is especially good to make the dibenzoate. These observations led directly to the discovery that NHC‐boranes also react with benzoic acid and related carboxylic acids under radical (but not thermal) conditions. Chain mechanisms for reactions with both reagents are suggested in which the key step is addition of an NHC‐boryl radical to the carbonyl oxygen of either the peroxide or the acid. magnified image
Topics & Concepts
ChemistryBoranesBenzoic acidPeroxideReagentOrganic chemistryMedicinal chemistryCombinatorial chemistryBoronOrganoboron and organosilicon chemistryRadical Photochemical ReactionsCatalytic Cross-Coupling Reactions