palladium-catalyzed allylicsubstitutions of a wide range of substrate types and nucleophiles using a bidentate ligand composed of oxazoline and chirally flexible biaryl phosphite elements. This unusually wide substrate scope is shown by experimental and theoretical studies of its η3-allyl and η2-olefin complexes not to be a result of configurational interconversion of the biaryl unit, since the ligand
Palladium–(S,pR)-FerroNPS-Catalyzed Asymmetric Allylic Etherification: Electronic Effect of Nonconjugated Substituents on Benzylic Alcohols on Enantioselectivity
作者:Fuk Loi Lam、Terry Tin-Lok Au-Yeung、Fuk Yee Kwong、Zhongyuan Zhou、Kwok Yin Wong、Albert S. C. Chan
DOI:10.1002/anie.200703955
日期:2008.2.1
Ionic-salt-tagged ferrocenyl diphosphine–imine ligands and their application to palladium-catalyzed asymmetric allylic etherification
A new type of ferrocenyl diphosphine-imine ligands that contains an ionic salt group has been prepared, and successfully applied to asymmetric C*-O bond formation. In the Pd-catalyzed asymmetric allylic etherification of 1,3-diphenyl-2-propenyl acetate, high enantioselectivity was obtained (up to 91.0% ee). The potential of the catalysts to be recycled and reused has also been demonstrated. (C) 2011 Elsevier Ltd. All rights reserved.
Chiral SO/P hybrid ligands: an enantioselective switch in palladium-catalyzed asymmetric allylic etherifications
作者:Junwei Xing、Peng Cao、Jian Liao
DOI:10.1016/j.tetasy.2012.03.022
日期:2012.4
A variety of chiral tert-butanesulfinylphosphine ligands were prepared and applied to the palladium-catalyzed asymmetric allylic etherification of 1,3-diphenylpropenyl acetate with alcohols. Excellent yields and moderate enantioselectivities were obtained. The absolute configuration of the etherification products was evidently switched only through the position change of the substituent on the P-aryl groups. (C) 2012 Elsevier Ltd. All rights reserved.