Electrophilic chemistry of propargylic alcohols in imidazolium ionic liquids: Propargylation of arenes and synthesis of propargylic ethers catalyzed by metallic triflates [Bi(OTf)3, Sc(OTf)3, Yb(OTf)3], TfOH, or B(C6F5)3
作者:Gopalakrishnan Aridoss、Viorel D. Sarca、James F. Ponder Jr、Jessica Crowe、Kenneth K. Laali
DOI:10.1039/c0ob00872a
日期:——
formed. Steric influence of the propargylic moiety on substrate selectivity is reflected in the lack of ortho propargylation for phenol and ethylbenzene by using propargylic alcohol Ia, and notable formation of the ortho isomer employing alcohol Ib. In the later case para selectivity could be increased by running the reaction at r. t. for 10 h. The Bi(OTf)3-catalyzed reaction of 1,3-dimethoxybenzene with
固定在咪唑鎓离子液体[BMIM] [BF 4 ],[BMIM] [PF 6 ]和[BMIM] [OTf]中的金属三氟甲磺酸M(OTf)3(M = Bi,Sc,Yb)是有效的系统,炔丙醇1,3-二苯基-2-丙炔-1-醇Ia的罐反应,1-甲基-3-苯基-2-丙炔-1-醇 Ib和2-戊炔-1-醇 在温和条件下,IC具有广泛的带有活化取代基的芳烃。[BMIM] [PF 6 ] / B(C 6 F 5)3和[BMIM] [PF 6 ] / TfOH体系在与Ib和Ic的炔丙基化反应中表现优异,而与3-苯基-2-丙炔-1-醇 与活化的芳族化合物同上导致代替地形成二芳基-丙烷。炔丙基化苯甲醚用磅中号下(OTF)3个催化是高度对位选择性,但是具有三氟乙酸或作为催化剂的B(C 6 F 5)3,也形成了邻位异构体。炔丙基部分对底物选择性的立体影响反映为缺乏邻炔丙基化。苯酚 和 乙苯通过使用炔丙醇Ia,并显着形成