A Highly Stereoselective Synthesis of α-Carbethoxy-α,β-unsaturated Phosphonates Mediated by Tri-n-Butylarsine
摘要:
A highly stereoselective synthesis of alpha-carbethoxy-alpha,beta-unsaturated phosphonates in 71-92% yield mediated by tri-n-butylarsine under neutral condition is described.
A Catalytic Michael/Horner-Wadsworth-Emmons Cascade Reaction for Enantioselective Synthesis of Thiochromenes
作者:Abhijnan Ray Choudhury、Santanu Mukherjee
DOI:10.1002/adsc.201300281
日期:2013.7.8
A catalyticenantioselective sulfa‐Michael/Horner–Wadsworth–Emmonsreactioncascade has been developed, taking advantage of phosphonate as an electrophilic activator and a traceless binding site. Using a chiral bifunctional urea derivative as the catalyst, a variety of aryl and heteroaryl substituted thiochromenes was obtained in excellent yield with a high level of enantioselectivity.
Treatment of aromatic α-phosphorylacrylate derivatives 1a-h with Mg turnings in the presence of trimethylsilyl chloride brought about facile and regioselective C-silylation to give the corresponding β-silylated phosphonates 2a-h in excellent yields. The reaction took place smoothly for activated olefins possessing appropriate reduction potentials and may be initiated by electron transfer from Mg to 1a-h.
A Highly Stereoselective Synthesis of α-Carbethoxy-α,β-unsaturated Phosphonates Mediated by Tri-n-Butylarsine
作者:Yanchang Shen、Baozhen Yang
DOI:10.1080/00397919308011152
日期:1993.12
A highly stereoselective synthesis of alpha-carbethoxy-alpha,beta-unsaturated phosphonates in 71-92% yield mediated by tri-n-butylarsine under neutral condition is described.