Complexes of borane and N-heterocyclic carbenes: a new class of radical hydrogen atom donor.
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.
Ueng
Shau-Hua
SH
Institut de chimie moléculaire (FR 2769), Laboratoire de chimie organique (UMR CNRS 7611), UPMC Univ Paris 06, C. 229, 4 place Jussieu, 75005 Paris, France.
Brahmi
Malika Makhlouf
MM
Derat
Etienne
E
Fensterbank
Louis
L
Lacôte
Emmanuel
E
Malacria
Max
M
Curran
Dennis P
DP