Concise Synthesis of Functionalized Benzocyclobutenones.

Autor: Chen PH; Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States., Savage NA; Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States., Dong G; Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.
Jazyk: angličtina
Zdroj: Tetrahedron [Tetrahedron] 2014 Jul 08; Vol. 70 (27-28), pp. 4135-4146.
DOI: 10.1016/j.tet.2014.03.080
Abstrakt: A concise approach to access functionalized benzocyclobutenones from 3-halophenol derivatives is described. This modified synthesis employs a [2+2] cycloaddition between benzynes generated from dehydrohalogenation of aryl halides using LiTMP and acetaldehyde enolate generated from n -BuLi and THF, followed by oxidation of the benzocyclobutenol intermediates to provide benzocyclobutenones. The [2+2] reaction can be run on a 10-gram scale with an increased yield. A number of functional groups including alkenes and alkynes are tolerated. Coupling of benzynes with ketene silyl acetals to give 8-substituted benzocyclobutenones is also demonstrated.
Databáze: MEDLINE
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