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Updated: Jun 13, 2026

Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
A formal [4 + 4] complementary ambiphile pairing reaction: a new cyclization pathway for ortho-quinone methides
Thiwanka B Samarakoon1, Moon Y Hur, Ryan D Kurtz
1Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045-7582, USA.
None:
A formal, one-pot [4 + 4] cyclization pathway for the generation of eight-membered sultams via in situ generation of an ortho-quinone methide (o-QM) is reported. The pairing of ambiphilic synthons in a complementary fashion is examined whereby o-fluorobenzenesulfonamides are merged with in situ generated o-QM in a formal [4 + 4] cyclization pathway to afford 5,2,1-dibenzooxathiazocine-2,2-dioxide scaffolds under microwave (mW) conditions. The method reported represents the first use of an o-QM in a formal hetero [4 + 4] cyclization.
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Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
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