Straightforward Synthesis of Dihydrobenzo[<i>a</i>]fluorenes through Au(I)-Catalyzed Formal [3 + 3] Cycloadditions
作者:Patricia García-García、Muhammad A. Rashid、Ana M. Sanjuán、Manuel A. Fernández-Rodríguez、Roberto Sanz
DOI:10.1021/ol3020682
日期:2012.9.21
Dihydrobenzo[a]fluorene derivatives have been prepared by a formal intramolecular [3 + 3] cycloaddition of o-alkynylstyrenes bearing a secondary alkyl group at the β-position of the styrene moiety. The process, catalyzed by a cationic gold(I) complex, involves a 1,2-hydride migration as the key step. 6,11-Dihydro-5H-benzo[a]fluorenes could be obtained from the initially generated 6,6a-dihydro-5H-benzo[a]fluorenes
二氢苯并[ α ]芴衍生物是通过在苯乙烯部分的β位带有仲烷基的邻炔基苯乙烯的分子内[3 + 3]环式加成反应制备的。该过程由阳离子金(I)络合物催化,涉及1,2-氢化物迁移为关键步骤。通过随后在金(I)或布朗斯台德酸下加热反应混合物,可以从最初生成的6,6a-二氢-5 H-苯并[ a ]芴获得6,11-二氢-5 H-苯并[ a ]芴。催化或直接在高温下进行反应。