Simple and efficient cleavage of the N-(1-phenylethyl) unit of carboxamides with methanesulfonic acid
摘要:
Cleavage of the N-(1-phenylethyl) unit of carboxamides using less than 1 equiv of MsOH in refluxing toluene was found to be simple and very efficient leading to the desired amides in good to excellent yields, and also proved to be more effective compared with reductive methods using hydrogen Sources, or acid hydrolysis reagents Such as TFA and TsOH. The method selectively cleaved only the N-(1-phenylethyl) group of N-benzyl-N-(1-phenylethyl)amides. (c) 2006 Elsevier Ltd. All rights reserved.
The formation of amides through the in situactivation of carboxylicacids with [Et2NSF2]BF4 is presented. A wide range of carboxylicacids and amines were used to produce the corresponding amides in up to 99 % yield. The reaction of hindered amines was also possible in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) under slightly modified conditions. An enantiopure carboxylicacid and amine
Direct conversion of esters to secondary amides using tin(II) reagents
作者:Wei-Bo Wang、José A. Restituyo、Eric J. Roskamp
DOI:10.1016/s0040-4039(00)79291-4
日期:1993.11
We have developed two new procedures for the direct conversion of esters to secondary amides. In our first procedure, secondary amides can be prepared in 83–98% yield starting from glycol esters. Addition of Sn[N(TMS)2]2 and a primary amine to the glycol ester generates an intermediate tin(II) alkoxy amide, which delivers the amino group intramolecularly to give the amide. A second general procedure
Air-stable Bis(pentamethylcyclopentadienyl) Zirconium Perfluorooctanesulfonate as an Efficient and Recyclable Catalyst for the Synthesis of N-substituted Amides
Bis(pentamethylcyclopentadienyl) zirconium perfluorooctanesulfonate is an air‐stable and water‐tolerant Lewis acid. This complex exhibited good thermal stability and high solubility in polar organic solvents. The compound showed relatively strong acidity, with an acid strength of 0.8
Ammonium Nitrate: A Biodegradable and Efficient Catalyst for the Direct Amidation of Esters under Solvent-free Conditions
作者:Perla Ramesh、Nitin W. Fadnavis
DOI:10.1246/cl.140846
日期:2015.2.5
A simple, metal-free, and environment-friendly procedure is developed for the direct conversion of esters to amides using ammonium nitrate as a catalystundersolvent-freeconditions. Aryls, hetero...
Aminolysis of esters by using the organocatalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) is reported. Secondary and tertiary amides were synthesized from alkyl or aryl esters with a variety of primary and secondaryamines in good to excellent yields (60–94%) under solvent-free conditions (SFC).