Remote ether groups-directed regioselective and chemoselective cycloaddition of azides and alkynes

Remote ether groups could be used as directing groups to prepare fully substituted 5-ether-1,2,3-triazoles with exclusive 1,5-regioselectivities and excellent chemoselectivities. Ether group could coordinate with iridium catalyst by lone-pair electron at a distance (up to four sigma bonds) away from alkyne to control the regioselectivity by weak coordination effect. The cycloaddition reaction chemoselectively occurred at the propargyl ether moiety of diyne to give unique fully substituted 4-alkynyl-triazole. (C) 2019 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

Remote ether groups can be utilized as directing groups to achieve exclusive 1,5-regioselectivities and excellent chemoselectivities in the synthesis of fully substituted 5-ether-1,2,3-triazoles. Coordination of ether group with iridium catalyst enables control of regioselectivity through weak coordination effect. The chemoselective cycloaddition reaction occurs at the propargyl ether moiety of diyne, yielding unique fully substituted 4-alkynyl-triazole.