Microwave-Promoted Three-Component Coupling of Aldehyde, Alkyne, and Amine via C−H Activation Catalyzed by Copper in Water

Abstract

[reaction: see text] An efficient three-component coupling of aldehyde, alkyne, and amine to generate propargylamines has been effected under microwave irradiation in water using only CuI catalyst without the noble metal cocatalyst. This method has proved to be applicable to a wide range of substrates. In addition, the preliminary experiment using (S)-proline methyl ester as a chiral source demonstrated that it could be developed to be a direct and highly diastereoselective method for construction of chiral propargylamines.

Asymmetric Multicomponent Reactions (AMCRs): The New Frontier

“…[79] The diastereoselective version of this MCR reaction with chiral amines did not have any advantage. [79,80] Different allylamines have been obtained by the MCR of 1-phenylpropyne, triethylborane, and N-methyl aryl imines catalyzed by substoichiometric amounts of a nickel complex and the chiral phosphane 51.…”

Catalyzed Reactions of Alkynes in Water

“…[78] An ultrasound-assisted version of A 3 coupling also has been shown to be highly effective in the presence of CuI as the catalyst in water at an ambient temperature. [79] Formaldehyde as substrates for CuI-catalyzed A 3 coupling in an aqueous solution has been reported recently.…”

One-pot multicomponent route to propargylamines using ferric hydrogensulfate

“…On the basis of several literature publications [30][31][32], it is believed that the coupling reaction mechanism proceeds by terminal alkyne C-H bond activation by ferric hydrogensulfate catalyst (Figure 2). The Fe-alkenyl (acetylide) intermediate would attack on iminium ion, which is prepared in situ from the aldehyde and secondary amine, to obtain the corresponding propargylamine and regenerated the catalyst for further reactions.…”