Silver-Catalyzed Cascade Cyclization of Amino-NH-1,2,3-Triazoles with 2-Alkynylbenzaldehydes: An Access to Pentacyclic Fused Triazoles

Abstract

An operationally simple Ag(I)-catalyzed approach for the synthesis of isoquinoline and quinazoline fused 1,2,3-triazoles was developed by a condensation and amination cyclization cascade of amino-NH-1,2,3-triazoles with 2-alkynylbenzaldehydes involving three new C-N bond formations in one manipulation, in which the group of -NH of the triazole ring serves as a nucleophile to form the quinazoline skeleton. The efficient protocol can be applied to a variety of substrates containing a range of functional groups, delivering novel pentacyclic fused 1,2,3-triazoles in good-to-excellent yields.

Silver-catalyzed synthesis of nitrogen heterocycles: recent advancements

“…In 2022, an operationally simple cascade strategy for the synthesis of pentacyclic fused triazoles using silver catalysis was introduced by Jiang and co-workers. 88 and this delivered the expected quinazoline and isoquinoline fused 1,2,3-triazoles 132 in high to excellent yields (Scheme 49). The protocol shows wide substrate scope and excellent functional group tolerance.…”

“…In 2022, an operationally simple cascade strategy for the synthesis of pentacyclic fused triazoles using silver catalysis was introduced by Jiang and co-workers. 88 This tandem condensation/amination cyclization was done by reacting 2-alkynylbenzaldehydes 131 with amino-NH-1,2,3-triazoles 130 in the presence of 10 mol% AgNO 3 63 in DMF at 80 °C for 2 h, and this delivered the expected quinazoline and isoquinoline fused 1,2,3-triazoles 132 in high to excellent yields (Scheme 49). The protocol shows wide substrate scope and excellent functional group tolerance.…”