Categories: C-N Bond Formation >
Synthesis of guanidines
Recent Literature
Simple lanthanide amides are highly efficient catalysts for the guanylation of
both aromatic and secondary amines with a high activity under mild conditions.
These catalysts are compatible with a wide range of solvents and substrates.
Q. Li, S. Wang, S. Zhou, G. Yang, X. Zhu, Y. Liu, J. Org. Chem.,
2007,
72, 6763-6767.
Q. Li, S. Wang, S. Zhou, G. Yang, X. Zhu, Y. Liu, J. Org. Chem.,
2007,
72, 6763-6767.
Ytterbium triflate is an efficient catalyst for the addition of a wide scope of
amines to carbodiimides under solvent-free condition to provide N,N',N''-trisubstituted
guanidines in good yields.
X. Zhu, Z. Du, F. Xu, Q. Shen, J. Org. Chem., 2009,
74, 6347-6349.
The use of cyanuric chloride (TCT) instead of classical HgCl2 as
activating reagent for di-Boc-thiourea provides an alternative route for the
guanylation of amines and eliminates the environmental hazard of
heavy-metal waste without appreciable loss of yield or reactivity.
A. Porcheddu, L. De Luca, G. Giacomelli, Synlett, 2009,
3368-3372.
Two new guanidinylation reagents, N,N′-bis(ortho-chloro-Cbz)-S-methylisothiourea
and N,N′-bis(ortho-bromo-Cbz)-S-methylisothiourea,
proved to be superior to already known reagents. The guanidinylations of
amines with all reagents were accelerated by addition of DMAP.
T. Gers, D. Kunce, P. Markowski, J. Izdebski, Synthesis, 2004,
37-42.
A convenient one-step transformation of primary and secondary amines into
the corresponding unprotected guanidines using 4-benzyl-3,5-dimethyl-1H-pyrazole-1-carboxamidine
and its polymer-bound variant is described. The scopes and limitations of
the method, the microwave-assistance of amidination as well as a recycling
protocol are examined.
W. Solodenko, P. Bröker, J. Messinger, U. Schön, A. Kirschning,
Synthesis, 2006, 461-466.
The synthesis of 3,5-dimethyl-N-nitro-1-pyrazole-1-carboxamidine (DMNPC) has been optimised. A detailed protocol for the preparation of a range of guanidines via nitroguanidines
is described using DMNPC as guanidinylating reagent.
J. A. Castillo-Meléndez, B. T. Golding, Synthesis,
2004,
1655-1663.
Primary amines are converted to protected NG-hydroxyguanidines
in a one-pot procedure using readily prepared materials. A high-yielding
preparation of NG-hydroxy-L-arginine, the intermediate in
the enzymatic conversion of L-arginine to nitric oxide and L-citrulline by
nitric oxide synthase, is described.
N. I. Martin, J. J. Woodward, M. A. Marletta, Org. Lett.,
2006,
8, 4035-4038.
