Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg (Germany) http://www.hashmi.de.
Angew Chem Int Ed Engl. 2014 Jan 20;53(4):1148-51. doi: 10.1002/anie.201307685. Epub 2013 Dec 11.
The reaction of an α-ketoaldehyde and a terminal alkyne in the presence of piperidine and a catalytic amount of AuCl delivers 1,2-dicarbonyl-3-enes, products of the formal hydroacylation of the triple bond. The scope of the method is broad; different aryl substituents on the dicarbonyl unit and on the alkyne are well tolerated. The products can be transformed selectively into vinylquinoxalines. Mechanistic studies, including isotope-labeling experiments, indicate that after an initial A(3) -type conversion to propargylic amines, a subsequent base-mediated alkyne-to-allene isomerization and a hydrolysis of the enamine substructure during the workup deliver the formal hydroacylation products.
在哌啶和催化量的 AuCl 的存在下，α-酮醛和末端炔烃的反应生成 1,2-二羰基-3-烯，这是三键的形式氢甲酰化产物。该方法的适用范围很广；二羰基单元和炔烃上的不同芳基取代基都能很好地耐受。产物可以选择性地转化为乙烯基喹喔啉。包括同位素标记实验在内的机理研究表明，在初始 A(3)型转化为炔丙胺后，随后的碱介导的炔烃至丙二烯异构化以及在后处理过程中烯胺亚结构的水解，生成了形式氢甲酰化产物。
