Nucleophilic displacement in 2-chloro(trifluoromethyl)pyridines with amines and ammonia
摘要:
The activating effect of trifluoromethyl groups in 2-chloro(trifluoromethyl)pyridines was investigated by comparing reactions of these compounds and of 2-chloropyridine with secondary cyclic amines. The ammonolysis of 2-chloro-3-trifluoromethylpyridine and 2-chloro-4-trifluoromethylpyridine is also reported and shown to proceed, in contrast to the reported behaviour of 2-chloro-5-trifluoromethylpyridine, without hydrolysis of the trifluoromethyl function. Both 2-amino-3-trifluoromethylpyridine and 2-amino-4-trifluoromethylpyridine were converted (via the corresponding pyridones) to 3-trifluoromethylpyridin-2(1H)-thione and 4-trifluoromethylpyridin-2(1H)-thione, and a number of S-alkyl derivatives of the latter compounds were prepared. (C) 1999 Elsevier Science S.A. All rights reserved.
Nucleophilic displacement in 2-chloro(trifluoromethyl)pyridines with amines and ammonia
作者:A.D Dunn
DOI:10.1016/s0022-1139(98)00308-x
日期:1999.2
The activating effect of trifluoromethyl groups in 2-chloro(trifluoromethyl)pyridines was investigated by comparing reactions of these compounds and of 2-chloropyridine with secondary cyclic amines. The ammonolysis of 2-chloro-3-trifluoromethylpyridine and 2-chloro-4-trifluoromethylpyridine is also reported and shown to proceed, in contrast to the reported behaviour of 2-chloro-5-trifluoromethylpyridine, without hydrolysis of the trifluoromethyl function. Both 2-amino-3-trifluoromethylpyridine and 2-amino-4-trifluoromethylpyridine were converted (via the corresponding pyridones) to 3-trifluoromethylpyridin-2(1H)-thione and 4-trifluoromethylpyridin-2(1H)-thione, and a number of S-alkyl derivatives of the latter compounds were prepared. (C) 1999 Elsevier Science S.A. All rights reserved.
First selective direct mono-arylation of piperidines using ruthenium-catalyzed C–H activation
作者:Maria C. Schwarz、Navid Dastbaravardeh、Karl Kirchner、Michael Schnürch、Marko D. Mihovilovic
DOI:10.1007/s00706-013-0947-1
日期:2013.4
A Ru-catalyzed mono-arylation in alpha-position of saturated cyclic amines is reported employing a C-H activation protocol. Substitution of the pyridine directing group with a bulky group, e.g., trifluoromethyl in the 3-position, proved to be crucial to avoid bis-arylation. This highly selective transformation can be performed with different amines and arylboronate esters. Additionally, the directing group can be cleaved, taking advantage of an unprecedented detrifluoromethylation reaction.