Synergy or Competition between Palladium-Catalysis and KF/Alumina-Mediation for the Allylic Substitution of the Acetates of Baylis–Hillman Adducts by Phenols
作者:Olivier Roy、Abdelkhalek Riahi、Françoise Hénin、Jacques Muzart
DOI:10.1016/s0040-4020(00)00727-4
日期:2000.10
The addition of various substituted phenols [XC6H4OH, X=H, o-CHO, o-CO2Me, o-CO2CH2Ph, o-CN, m-NHCOMe, m-OMe, p-OMe, p-CHO, p-Cl] to allylic acetates obtained from Baylis–Hillman adducts [RCH(OAc)C(CH2)CO2Et, R=H, n-Pr] has been studied in the presence of a Pd(0) catalyst and/or KF/alumina. In some cases, the use of one of these two reagents was sufficient to promote the OAc/OAr exchange but in general
添加各种取代的苯酚[XC 6 H 4 OH,X = H,o -CHO,o -CO 2 Me,o -CO 2 CH 2 Ph,o -CN,m -NHCOMe,m -OMe,p -OMe ,p -CHO,p -Cl]从的Baylis-希尔曼加合物得到烯丙基乙酸酯[RCH(OAC)C(CH 2)CO 2的Et,R = H,ñ-Pr]已在Pd(0)催化剂和/或KF /氧化铝的存在下进行了研究。在某些情况下,使用这两种试剂中的一种足以促进OAc / OAr交换,但通常,将两种试剂一起使用时,反应更快,产率更高。证据两条路线,η 3 π-烯丙基中间体和迈克尔加成/消除,然后获得同时的Heck型反应可以在中性条件下参与。