Metal-free [3+2] cycloaddition of azides with Tf2C
CH2 for the regioselective preparation of elusive 4-(trifluoromethylsulfonyl)-1,2,3-triazoles†
Abstract
1,2-Dipole Tf2CCH2 is generated in situ and immediately reacts at room temperature with an azide to afford previously unknown 4-trifluoromethanesulfonyl 1,2,3-triazoles through a stepwise [3+2] cycloaddition reaction. Noteworthily, this mild and powerful uncatalyzed protocol is highly regio- and chemoselective.