113709-60-7Relevant academic research and scientific papers
Gold(I)-catalyzed diastereoselective hydroacylation of terminal alkynes with glyoxals
Shi, Shuai,Wang, Tao,Weingand, Vanessa,Rudolph, Matthias,Hashmi, A. Stephen K.
, p. 1148 - 1151 (2014)
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 A3-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. The simple AuCl catalyst and piperidine convert terminal alkynes and α-ketoaldehydes into 1,2-dicarbonyl-3-enes, the products of a formal hydroacylation of the triple bond, with excellent regio- and diastereoselectivity. There is no evidence for classical A3 coupling products, which could be expected from such a gold-catalyzed reaction of an aldehyde, an amine, and a terminal alkyne. Copyright
