Si-directed regiocontrol in asymmetric Pd-catalyzed allylic alkylations using C1-ammonium enolate nucleophiles

TETRAHEDRON

卷:74

Article

Fyfe, James W. B.¹  Kabia, Omaru M.¹  Pearson, Colin M.¹  Snaddon, Thomas N.¹ 

[1] Indiana Univ, Dept Chem, 800 E Kirkwood Ave, Bloomington, IN 47405 USA

关键词: Cooperative catalysis;    Allylic alkylation;    Silicon;    Palladium;    Ammonium enolate;   

DOI  :  10.1016/j.tet.2018.04.021

来源: Elsevier

【 摘 要 】

Cooperative catalysis enables the direct enantioselective alpha-allylation of linear prochiral esters using Si-substituted allyl electrophiles. The Si-substituent directs the regioselectivity of enantioselective bond formation and provides products containing synthetically versatile pentafluorophenyl ester and vinylsilane moieties. Critical to the efficacy of this process was the recognition that the ancillary ligand on palladium could be altered to prevent formation of a deleterious ether by-product, whilst retaining enantioselectivity through the Lewis base catalyst. Flexibility such as this is unique to cooperative catalysis events and provides efficient access to an array of enantioenriched products that are orthogonally functionalized and easily modified. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

Free