1207166-24-2Relevant academic research and scientific papers
Reaction prospecting by 31P NMR: enantioselective rhodium-DuPhos catalysed addition of ZnMe2 to diphenylphosphinoylimines
Crampton, Rosemary H.,Hajjaji, Samir El,Fox, Martin E.,Woodward, Simon
scheme or table, p. 2497 - 2503 (2010/04/05)
Chiral shift 31P NMR spectroscopy allows the identification of ligand leads in asymmetric catalyst systems for ZnMe2 addition to ArCH{double bond, long}NP(O)Ph2. Subsequent GC-based optimisation shows [RhCl(CH2{double bond, long}CH2)2]2 and (R,R)-MeDuPhos to be the optimal pre-catalyst combination (product in 78-93% ee). Transmetallation of [(MeDuPhos)Rh{N(P(O)Ph2-CHMeAr}] with ZnMe2 appears to be the rate limiting step of the catalytic cycle as competing coordination by the imine starting material leads to Ph2P(O)NHCH2Ar via MVP hydrogen-transfer. This limitation can largely be overcome by the slow addition of the imine.
