Year: 2009
Type: editorial
Abstract: Significance Looper and co-workers described a three-step synthesis of highly substituted 2-aminoimidazoles. The first step consists of the preparation of propargyl cyanamides by copper(I)-catalyzed addition of an iminium generated from condensation of aldehydes (R ² = alkyl or aryl) with secondary amines. Without further purification, the resulting tertiary amines are subjected to a von Braun reaction. The use of 4-methoxybenzyl-, 2,4- and 3,4-dimethoxybenzyl-substituted propargyl amines lead to the propargyl cyanamides in good yields whereas symmetric N , N -dialkylpropargyl amines give exclusively propargyl bromide. Screening of catalysts led to the use of La(OTf) 3 for the final addition-hydroamination step. Both acyclic and cyclic secondary amines generated guanidine intermediates which underwent cyclization to the alkyne to afford 2-aminoimidazoles in good yields.
Source: Synfacts
Authors: R. L. Giles, J. D. Sullivan, A. M. Steiner, R. E. Looper
Institution: University of Utah
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1983464912