A novel one-pot synthesis of polysubstituted oxa(thia)zolidin-2-imines has been developed. It employs A(3)-coupling of aldehyde and amine with alkyne to form propargyl amine, which on (thio) amidation with iso(thio)cyanate produces N-propargyl(thio)urea, and a cyclization reaction. A 5-exo-dig iodocyclization of N-propargylurea constructs 5-iodomethyleneoxazolidin-2-imine, while cycloisomerization of the thio analogue provides 5-methylenethiazolidin-2-imine. In this process, CuI catalysis has been found to be crucial, and the cyclization occurs through oxygen/sulfur (not nitrogen) nucleophilic attack to alkyne.
Facile and diverse microwave-assisted synthesis of secondary propargylamines in water using CuCl/CuCl<sub>2</sub>
作者:Tran Thi Thu Trang、Denis S. Ermolat'ev、Erik V. Van der Eycken
DOI:10.1039/c4ra16005c
日期:——
A highly efficient microwave-assisted three-component reaction between an aldehyde, a primary amine and an alkyne was developed using an inexpensive Cu(i)/Cu(ii) catalytic system and water as solvent.