title: Effect of theortho-hydroxy group of salicylaldehyde in the A3coupling reaction: A metal-catalyst-free synthesis of propargylamine.
abstract: The synthesis of propargylamines via A3coupling mostly under metal-catalyzed procedures is well known. This work invented an unprecedented effect of salicylaldehyde, one of the A3coupling partners, which could lead to the formation of propargylamine, an important pharmaceutical building block, in the absence of any metal catalyst and under mild conditions. The role of the hydroxy group inorthoposition of salicylaldehyde has been explored, which presumably activates the Csp-H bond of the terminal alkyne leading to the formation of propargylamines in good to excellent yields, thus negating the function of the metal catalyst. This observation is hitherto unknown, tested for a variety of salicylaldehyde, amine and acetylene, established as a general protocol, and is believed to be of interest for synthetic chemists from green chemistry.
authors.affiliation: Department of Chemistry, University of North Bengal, Darjeeling 734013, India.
authors.forename: Sujit
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Department of Chemistry, University of North Bengal, Darjeeling 734013, India.
authors.forename: Kinkar
authors.initials: K
authors.lastname: Biswas
authors.affiliation: Department of Chemistry, University of North Bengal, Darjeeling 734013, India.
authors.forename: Suchandra
authors.initials: S
authors.lastname: Bhattacharya
authors.affiliation: Department of Chemistry, University of North Bengal, Darjeeling 734013, India.
authors.forename: Pranab
authors.initials: P
authors.lastname: Ghosh
authors.affiliation: Department of Chemistry, University of North Bengal, Darjeeling 734013, India.
authors.forename: Basudeb
authors.initials: B
authors.lastname: Basu
keywords: A3 coupling; metal-catalyst-free; propargylamine; salicylaldehyde; terminal alkyne