Cationic 1,2,3-Triazolium Alkynes: Components To Enhance 1,4-Regioselective Azide–Alkyne Cycloaddition Reactions
作者:Zaira Monasterio、Maialen Sagartzazu-Aizpurua、José I. Miranda、Yuri Reyes、Jesus M. Aizpurua
DOI:10.1021/acs.orglett.6b00055
日期:2016.2.19
thermal [3 + 2] cycloaddition reactions with azides roughly 50- to 100-fold faster than comparable noncharged alkynes. Further, the reaction is highly 1,4-regioselective (dr up to 99:1) owing to the selective stabilization of 1,4-TS transition states via conjugative π-acceptor assistance of the alkyne triazolium ring. The novel cationic triazolium alkynes also accelerate the CuAAC reaction to provide bis(1
4-炔基-1,2,3-三唑鎓阳离子经历热[3 + 2]环加成反应,叠氮化物的速度比不带电的炔烃快50到100倍。此外,由于经由炔三唑环的共轭π-受体辅助的1,4-TS过渡态的选择性稳定,该反应是高度1,4-区域选择性的(dr高达99:1)。新型阳离子三唑鎓炔烃还可以加速CuAAC反应,以“超快”方式(<5分钟)提供双(1,2,3-三唑)。