Complexes of Borane and N-Heterocyclic Carbenes: A New Class of Radical Hydrogen Atom Donor
作者:Shau-Hua Ueng、Malika Makhlouf Brahmi、Étienne Derat、Louis Fensterbank、Emmanuel Lacôte、Max Malacria、Dennis P. Curran
DOI:10.1021/ja804150k
日期:2008.8.1
Calculations suggest that complexes of borane with N-heterocyclic carbenes (NHC) have B-H bond dissocation energies more then 20 Kcal/mol less than free borane, diborane, borane-THF, and related complexes. Values are in the range of popular radical hydrogen atom donors like tin hydrides (70-80 Kcal/mol). The resulting prediction that NHC borane complexes could be used as radical hydrogen atom donors was verified by radical deoxygenations of xanthates by using either AIBN or triethylborane as initiator.