Simple Synthesis of Amides and Weinreb Amides Using PPh3 or Polymer-Supported PPh3 and Iodine
作者:Amit Kumar、Hari Kiran Akula、Mahesh K. Lakshman
DOI:10.1002/ejoc.200901420
日期:2010.5
range of carboxylic acids to 2 degrees , 3 degrees , and Weinrebamides. Simplification of the procedure was possible with the use of polymer-supported PPh3/I2. Weinrebamides produced via the use of polymer-supportedPPh3 could be filtered through a short silica gel plug and used in further transformations. Thus, use of polymer-supportedPPh3 offers potential applicability to diversity-oriented reactions
已经证明,PPh 3 / I 2的组合对于将一系列羧酸转化为2度,3度和Weinreb酰胺是有效的。使用聚合物负载的PPh3 / I2可以简化程序。通过使用聚合物负载的PPh3制备的Weinreb酰胺可以通过短硅胶塞过滤,并用于进一步的转化。因此,使用聚合物负载的PPh3可为面向多样性的反应提供潜在的适用性。通过使用这种酰胺形成方法,已经完成了载脂蛋白和普拉托恩的正式全部合成,以及脱水胆碱酮和马来帕定的合成。已尝试获得对该反应的了解。
New boron(III)-catalyzed amide and ester condensation reactions
meta- or para-position are highly effective catalysts for the amide condensation reaction in less-polar solvents. In this paper, we report that N-alkyl-4-boronopyridinium halides are more effective catalysts than the previous ones in more polar solvents. N-Alkyl-4-boronopyridinium halides are effective not only for amide condensation between equimolar mixtures of carboxylic acids and amines but also
N-Alkyl-4-boronopyridinium salts are highly effective and reusable catalysts for the dehydrative amide condensation reaction between equimolar mixtures of carboxylicacids and amines. N-Alkylboronopyridinium salts are thermally stabilized in the order N-alkyl-2-boronopyridinium salt << N-alkyl-3-boronopyridinium salt < N-alkyl-4-boronopyridinium salt. Homogeneous catalysts, such as 4-borono-N-methylpyridinium
The anticonvulsant activities of functionalized N-benzyl 2-acetamidoacetamides. The importance of the 2-acetamido substituent
作者:Daeock Choi、James P Stables、Harold Kohn
DOI:10.1016/s0968-0896(96)00225-8
日期:1996.12
Recent studies have demonstrated that substituted N-benzyl 2-acetamidoacetamides provide significant protection against maximal electroshock (MES)-induced seizures in mice and rats. In this study, we investigated whether the 2-acetamido moiety was necessary for anticonvulsant activity. Ten derivatives of the known anticonvulsant, N-benzyl 2-acetamido-2-phenyl acetamide were prepared in which the 2-acetamido group was replaced by hydrogen, methyl, oxygen, and halogen substituents. Evaluation of these compounds in the MES-induced seizure test demonstrated that both the hydroxy and the methoxy compounds provided full protection against MES-induced seizures in mice given ip at 100 mg/kg. Moreover, evaluation of the individual stereoisomers for the hydroxy compound showed that the principal activity resided in the (R)-isomer. These findings demonstrated that the 2-acetamido substituent is important but not obligatory for the prevention of MES-induced seizures. Further supporting evidence was provided by comparing the pharmacological activities of N-benzyl 2,3-dimethoxypropionamide with N-benzyl 2-acetamido-3-methoxypropionamide. The ED(50) value for the former in the MES test was 30 mg/kg (ip), which compared favorably with phenobarbital (ED(50) = 22 mg/kg), but the ED(50) value for N-benzyl 2-acetamido-3-methoxypropionamide was 8.3 mg/kg. Copyright (C) 1996 Elsevier Science Ltd
IRIUCHIJIMA SHINOBU; MANIWA KEIKO; TSUCHINASHI GEN-ICHI, AGR. AND BIOL. CHEM., 1976, 40, NO 12, 2389-2396