Reaction of Diphenylcarbene with Amines and the Question of Triplet-Singlet Equilibration

Article abstract of DOI:10.1021/ja00302a002

The optical absorption spectrum of triplet diphenylcarbene in solution is quenched by substrates such as methanol and amines to give the respective O-H and N-H insertion products.Is this a direct reaction of the triplet carbene with the substrates which runs counter to the rules of spin selection, or does it involve thermal population of the singlet state of the carbene which then reacts with the substrates? These Questions are addressed through kinetic, isotopic, and product studies of the reaction between diphenylcarbene and butylamines.