Department of Chemistry, University College London, Christopher Ingold Laboratories, 20 Gordon Street, London, WC1H 0AJ, UK.
J Am Chem Soc. 2010 May 5;132(17):5968-9. doi: 10.1021/ja102129c.
A new method for enolate generation via the gold-catalyzed addition of boronic acids to alkynes is reported. The formation of boron enolates from readily accessible ortho-alkynylbenzeneboronic acids proceeds rapidly with 2 mol % PPh(3)AuNTf(2) at ambient temperature. The enolates undergo aldol reaction with an aldehyde present in the reaction mixture to give cyclic boronate esters, which can be subsequently transformed into phenols, biaryls, or dihydrobenzofurans via oxidation, Suzuki-Miyaura, or intramolecular Chan-Lam coupling, respectively. A combined gold/boronic acid catalyzed aldol condensation reaction of an alkynyl aldehyde was also successfully achieved.
本文报道了一种通过金催化硼酸与炔烃加成生成烯醇化物的新方法。邻炔基苯硼酸易于制备，在室温下用 2 mol% PPh(3)AuNTf(2)反应迅速生成硼烯醇化物。烯醇化物与反应混合物中存在的醛发生Aldol 反应，生成环状硼酸酯，随后通过氧化、Suzuki-Miyaura 或分子内 Chan-Lam 偶联反应，分别转化为苯酚、联苯或二氢苯并呋喃。还成功地实现了炔基醛的金/硼酸协同催化Aldol 缩合反应。
