Stereoselective thia-Michael 1,4-Addition to Acyclic 2,4-Dienones and 2-En-4-ynones
作者:Rafał Kowalczyk、Przemysław J. Boratyński
DOI:10.1002/adsc.201501138
日期:2016.4.14
AbstractOrganocatalyzed highly stereoselective 1,4‐thia‐Michael addition of mercaptans to linear 2,4‐dienones and 2‐en‐4‐ynones was developed using Cinchona alkaloid‐based squaramides. Application of only 0.5–1 mol % loading afforded products in up to 98:2 e.r. and above 99:1 after a single recrystallization. The adducts of allyl mercaptan can be conveniently further transformed to new chiral 2‐substituted 2,5‐dihydrothiophenes by ring‐closing metathesis.magnified image
Über die Reaktionen von Guanidin bzw. Thioharnstoff mit α,β,γ,δ-ungesättigten Ketonen