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Updated: Sep 21, 2025

Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
Syntheses of 3-Aryl Tetrahydroisoquinolines via an Intermolecular [4 + 2] Cycloaddition of Sultines with Imines
Aurapat Ngamnithiporn1, Padon Chuentragool1, Poonsakdi Ploypradith1,2,3
1Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 54 Kamphaeng Phet 6 Road, Bangkok 10210, Thailand.
Abstract:
The development of an intermolecular aza-Diels-Alder (DA) cycloaddition of sultines and imines is reported. By exploiting sultines as o-quinodimethane precursors and aryl imines as dienophiles in the presence of Cu(OTf)2, an aza-DA reaction proceeds to provide a wide variety of 3-aryl tetrahydroisoquionlines in moderate to excellent yield (up to 89%). The synthetic utility of these products was demonstrated in the preparation of tetracyclic N-heterocycles, including a tetrahydroprotoberberine skeleton.
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