Ytterbium(III) triflate-catalyzed asymmetric nucleophilic addition of functionalized lithium (alpha-carbalkoxyvinyl)cuprates to chiral p-toluenesulfinimines (thiooxime S-oxides)

Authors
Li, GG Wei, HX Hook, JD
Citation
Gg. Li et al., Ytterbium(III) triflate-catalyzed asymmetric nucleophilic addition of functionalized lithium (alpha-carbalkoxyvinyl)cuprates to chiral p-toluenesulfinimines (thiooxime S-oxides), TETRAHEDR L, 40(25), 1999, pp. 4611-4614
Citations number
24
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON LETTERS
ISSN journal
00404039 → ACNP
Volume
40
Issue
25
Year of publication
1999
Pages
4611 - 4614
Database
ISI
SICI code
0040-4039(19990618)40:25<4611:YTANAO>2.0.ZU;2-X
Abstract
Ytterbium(III) triflate has been found to catalyze anionic additions of fun ctionalized lithium (alpha-carbalkoxyvinyl)cuprates to chiral p-toluenesulf inimines (thiooxime S-oxides) in a cosolvent system (Et2O-CH2Cl2). This new system has made it possible to utilize those p-toluenesulfinimines of low solubility in Et2O as the electrophiles to react with anionic (alpha-carbal koxyvinyl)cuprates for the asymmetric synthesis of the corresponding beta-m ono and beta,beta-disubstituted Baylis-Hillman adducts. Modest yields (51.0 -64.4% yield) and good to excellent diastereoselectivities (>90% de) were o btained. (C) 1999 Elsevier Science Ltd. All rights reserved.