Three‐Component [3 + 3] Heterocyclizations for Flexible Synthesis of Bicyclic Fused Pyridines Under Microwave Irradiation

Abstract

in Wiley Online Library (wileyonlinelibrary.com). Three-component [3 + 3] heterocyclizations have been established under microwave irradiation, providing a flexible synthetic approach toward bicyclic fused pyridines. 3,5-Dibenzylidenedihydro-2H-pyran-4(3H)ones were subject with malononitrile and aromatic amines in cosolvent of HOAc and N,Ndimethylformamide, affording 10 examples of pyrano[4,3-b]pyridine derivatives in good to excellent yields. Similarly, seven examples of thiopyrano[4,3-b]pyridine derivatives were obtained using sulfur-tethered heterocyclones as a reaction partner. a Isolated yields. Scheme 1. Synthesis of pyrano[4,3-b]pyridines 4 under MW.