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

✍ Scribed by Guigen Li; Han-Xun Wei; Jason D. Hook

• Book ID: 104261539
• Publisher: Elsevier Science
• Year: 1999
• Tongue: French
• Weight: 293 KB
• Volume: 40
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(99)00756-x

✦ Synopsis

Ytterbium(II1)

triflate has been found to catalyze anionic additions of functionalized lithium (CXcarbalkoxyvinyl)cuprates to chiral p-toluenesulfinimines (thiooxime S-oxides) in a cosolvent system (Et#-CH2C12). This new system has made it possible to utilize those p-toluenesulfinimines of low solubility in Et20 as the electrophiles to react with anionic (et-carbalkoxyvinyl)cuprates for the asymmetric synthesis of the corresponding B-mono and B,b-disubstituted Baylis-Hillman adducts. Modest yields (51.0-64.4% yield) and good to excellent diastereoselectivities (>90% de) were obtained.