1033618-36-8Relevant articles and documents
C2 symmetric chiral NHC ligand for asymmetric quaternary carbon constructing copper-catalyzed conjugate addition of Grignard reagents to 3-substituted cyclohexenones
Matsumoto, Yasumasa,Yamada, Ken-Ichi,Tomioka, Kiyoshi
, p. 4578 - 4581 (2008/09/21)
(Chemical Equation Presented) The asymmetric construction of quaternary carbon centers by conjugate addition of Grignard reagents to 3-methyl- and 3-ethylcyclohexenones was realized in a maximum enantioselectivity of 80% by using a C2 symmetric chiral N-heterocyclic carbene (NHC)-copper catalyst, generated from (4S,5S)-1,3-bis(2-methoxyphenyl)-4,5-diphenyl-4,5- dihydro-1H-imidazol-3-ium tetrafluoroborate and copper(II) triflate. The stereostructures of the NHC-Au complexes were analyzed by X-ray crystallography, which rationalized the good stereocontrolling ability of N-aryl NHCs.