Tetrahedron: Asymmetry

Reaction prospecting by 31 P NMR: enantioselective rhodium-DuPhos catalysed addition of ZnMe 2 to diphenylphosphinoylimines

RH Crampton, S El Hajjaji, ME Fox, S Woodward

文献索引：Crampton, Rosemary H.; Hajjaji, Samir El; Fox, Martin E.; Woodward, Simon Tetrahedron Asymmetry, 2009 , vol. 20, # 21 p. 2497 - 2503

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被引用次数: 18

摘要

Chiral shift 31P NMR spectroscopy allows the identification of ligand leads in asymmetric catalyst systems for ZnMe2 addition to ArCHNP (O) Ph2. Subsequent GC-based optimisation shows [RhCl (CH2CH2) 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 ...