A new method to access triazole-fused spiro-guanidines from the reaction of isothiocyanates tethered N-sulfonyl-1,2,3-triazoles and amines

Abstract

The reaction of isothiocyanate tethered N-sulfonyl-1,2,3-triazoles and amines afforded asymmetrical guanidines in fair to excellent yields through a two-component tandem reaction process.

Progress in the Synthesis of Fused 1,2,3‐Triazoles

“…A novel base assisted access to triazole‐fused spiro‐guanidine derivatives 324 from isothiocyanate tethered N ‐sulfonyl‐1,2,3‐triazoles 322 and amines 323 was revealed by Shi and coworkers (Scheme 102). [102] Good yields were procured from substrate bearing different N ‐protecting groups (Methyl, allyl, benzyl, phenyl and naphthalene‐2‐ylmethyl). Primary amines (aliphatic and aromatic) underwent the reaction very well but secondary amines displayed lower yields due to steric hindrance.…”

Base-Induced Highly Regioselective Synthesis of N2-Substituted 1,2,3-Triazoles under Mild Conditions in Air

“…The resulting enhanced reactivity at N -2 enables an efficient synthesis of 2,4-disubstituted 1,2,3-triazoles. Shi and co-workers have also reported a highly regioselective base-induced synthesis of N 2 -substituted triazoles from N -sulfonyl-1,2,3-triazoles and bis­(dialkylamino)­methane at 100 °C (Scheme b) . High regioselectivity was dictated by the 4-phenyl-2 H -1,2,3-triazoles intermediate ( 4a ), which was generated from the hydrolysis of N -sulfonyl-1,2,3-triazole as a more stable tautomer than the other one (4-phenyl-1 H -1,2,3-triazoles, 4a′ ) at a high temperature .…”