Versatile Chiral Bidentate Ligands Derived from α-Amino Acids: Synthetic Applications and Mechanistic Considerations in the Palladium-Mediated Asymmetric Allylic Substitutions
to other amino groups in the amidine skeleton and the production of other types of ligands, are possible using the precursor compounds of 7a. Thus, novel chiral ligands 7c,d, 8, 11, and 13, which provide sterically and electronically different chiral circumstances, were prepared and used for the palladium-mediated asymmetric allylic substitutions of both acyclic and cyclic compounds. In these reactions
New, Optically Active Phosphine Oxazoline (JM-Phos) Ligands: Syntheses and Applications in Allylation Reactions
作者:Duen-Ren Hou、Joseph H. Reibenspies、Kevin Burgess
DOI:10.1021/jo001333h
日期:2001.1.1
palladium-mediated allylation reactions. They proved to be most useful for asymmetric alkylation of 3-acetoxy-1,3-diphenylpropene and less suitable/effective for the more challenging substrates (a pentenyl derivative and a cyclohexenyl system). X-ray crystallographic analysis of the complex [(eta 3-PhCHCHCHPh)Pd(1a)][PF6] led to the conclusion that the origins of asymmetric induction in these systems
Newmonodentatechiralphosphines, (+)- and (−)-2,6-dimethyl-9-phenyl-9-phosphabicyclo[3.3.1]nonanes ((+)- and (−)-9-PBNs), were prepared from 1,5-dimethyl-1,5-cyclooctadiene, and their application to the asymmetricallylicsubstitutionreaction proved the utility of 9-PBNs as chiralphosphine ligands.
JM-PHOS Ligands: Second-Generation Phosphine Oxazolines for Asymmetric Catalysis
作者:Duen-Ren Hou、Kevin Burgess
DOI:10.1021/ol991008k
日期:1999.12.1
[GRAPHICS]A small library of phosphine oxazoline ligands 2 was prepared and tested in palladium mediated allylation processes (reactions 1 and 2). They were found to be superior to the first generation ligands 1 and as effective as the well known phosphine oxazolines 3.
HIYAMA, TAMEJIRO;WAKASA, NORIKO, TETRAHEDRON LETT., 1985, 26, N 27, 3259-3262