title: Concise Synthesis of Functionalized Benzocyclobutenones.
abstract: 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 fromn-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.
authors.affiliation: Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.
authors.forename: Peng-Hao
authors.initials: PH
authors.lastname: Chen
authors.affiliation: Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.
authors.forename: Nikolas A
authors.initials: NA
authors.lastname: Savage
authors.affiliation: Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.
authors.forename: Guangbin
authors.initials: G
authors.lastname: Dong
keywords: benzocyclobutenol; benzocyclobutenone; benzyne; cycloaddition; dehydrohalogenation