Categories: C-N Bond Formation >
Synthesis of guanidines
A modified Ullmann reaction allows the use of p-methoxybenzyl (PMB) guanidine as guanidinylation agent to give various aryl and heteroaryl guanidines in good yields.
H. Hammoud, M. Schmitt, F. Bihel, C. Antheaume, J.-J. Bourguignon, J. Org. Chem., 2012, 77, 417-423.
An operationally simple and rapid copper-catalyzed three-component synthesis of trisubstituted N-aryl guanidines involving cyanamides, arylboronic acids, and amines is performed in the presence of K2CO3, a catalytic amount of CuCl2·2H2O, bipyridine, and oxygen (1 atm).
J. Li, L. Neuville, Org. Lett., 2013, 15, 6124-6127.
Palladium-catalyzed alkene carboamination reactions between acyclic N-allyl guanidines and aryl or alkenyl halides provide substituted 5-membered cyclic guanidines in good yield. This method allows access to a number of different cyclic guanidine derivatives in only two steps from readily available allylic amines.
B. P. Zavesky, N. R. Babij, J. A. Fritz, J. P. Wolfe, Org. Lett., 2013, 15, 5420-5423.
A silver-catalyzed hydroamination of tosyl-protected N-allylguanidines provides substituted cyclic guanidines in high yields. The reactions can be used for construction of quaternary stereocenters as well as both monocyclic and bicyclic guanidine products.
Z. J. Garlets, M. Silvi, J. P. Wolfe, Org. Lett., 2016, 18, 2331-2334.
A novel electrophilic one-pot reaction of an olefin, a cyanimide, an amine, and N-bromosuccinimide enables the synthesis of a number of guanidine derivatives with very good yields - including an rTRTVI precursor.
L. Zhou, J. Chen, J. Zhou, Y.-Y. Yeung, Org. Lett., 2011, 13, 5804-5807.