Alternative formation of amides and β-enaminones from aroyl chlorides using the TiCl4-trialkylamine reagent system
The TiCl4/NR3 reagent system has been successfully employed for the synthesis of amides and β-enaminones. The reaction of variously substituted benzoyl chlorides with the TiCl4/NR3 reagent system, by using two different experimental procedures (Method A and Method B), afforded alternatively the corresponding amides and β-enaminones as unique or major products. The two developed protocols were investigated with a series of tertiary amines. The reactions, modulated by the presence of TiCl4, provided the corresponding amides or β-enaminones with satisfactory yields. This paper reports a new method for carbon-carbon bond formation via the reaction of aroyl chlorides with the TiCl4/NR3 reagent system.
Copper-catalyzed amidation of benzoic acids using tetraalkylthiuram disulfides as amine sources
A facile method for the copper-catalyzed synthesis of N-substituted benzamides was explored. In the presence of CuBr and di-tert-butyl peroxide, various N-substituted benzamides were prepared through amidation of benzoic acid by using commercially available and cheap tetraalkylthiuram disulfides as amine sources. With this protocol, a series of 14 N-substituted benzamides were furnished in good to excellent yields. The broad substrate scope and good to excellent yield show its practical synthetic value in organic synthesis.
Pd(ii)-catalyzed decarboxylative cross-coupling of oxamic acids with potassium phenyltrifluoroborates under mild conditions
A novel Pd-catalyzed decarboxylative cross-coupling of oxamic acids with potassium phenyltrifluoroborates has been realized under mild reaction conditions. This method provides an efficient access to N-mono- or N,N-disubstituted benzamides and benzoates.
Li, Mingzong,Wang, Cong,Fang, Ping,Ge, Haibo
supporting information; experimental part
p. 6587 - 6589
(2011/06/25)
Utility of dysprosium as a reductant in coupling reactions of acyl chlorides: The synthesis of amides and diaryl-substituted acetylenes
Reduction of acyl chlorides with dysprosium metal has been studied. The reducing ability of dysprosium metal is solvent-dependent. Dysprosium metal, which requires neither any additive nor pretreatment, can promote the cross-coupling of acyl chlorides in DMF or DEF to give amides in good yields. When the reaction was performed in N,N-dimethylacetamide, the reductive self-coupling reaction of aroyl chloride took place smoothly and afforded the diaryl-substituted acetylenes in moderate to good yield.