Triphenyl borate catalyzed synthesis of amides from carboxylic acids and amines
作者:Seema A. Ghorpade、Dinesh N. Sawant、Nagaiyan Sekar
DOI:10.1016/j.tet.2018.10.030
日期:2018.11
Herein we report triphenyl borate as a new catalyst for synthesis of amides by catalytic condensation of carboxylic acids and amines. Our protocol is applicable for synthesis of wide range of amides furnishing excellent yields up to 92%. In addition developed method requires low catalyst loading, short time, less amount of solvent, works under air atmosphere and notably no need of azeotropic reflux
The Ketene-Surrogate Coupling: Catalytic Conversion of Aryl Iodides into Aryl Ketenes through Ynol Ethers
作者:Wenhan Zhang、Joseph M. Ready
DOI:10.1002/anie.201405036
日期:2014.8.18
tert‐Butoxyacetylene is shown to undergo Sonogashira coupling with aryliodides to yield aryl‐substituted tert‐butyl ynol ethers. These intermediates participate in a [1,5]‐hydride shift, which results in the extrusion of isobutylene and the generation of aryl ketenes. The ketenes are trapped in situ with multiple nucleophiles or undergo electrocyclic ring closure to yield hydroxynaphthalenes and quinolines
General Synthesis of Fully Substituted 4-Aminooxazoles from Amides and 1,4,2-Dioxazol-5-ones Based on Amide Activation and Umpolung Process
作者:Yunxiang Weng、Lin Min、Lidong Shan、Hongchen Li、Xinyan Wang、Yuefei Hu
DOI:10.1021/acs.joc.0c02015
日期:2021.1.1
A general and efficientsynthesis of fully substituted 4-aminodixazoles was developed based on the strategies of amide activation and umpolung reaction. In this method, 1,4,2-dioxazol-5-ones were introduced as a rare type of umpolung reagent bearing a nucleophilic N-atom that could be used well together with the activating agent Tf2O. Because 1,4,2-dioxazol-5-ones played triple roles as an umpolung
We have developed an organocatalyticasymmetricMichaelreaction of acylsilane through the selection of acylsilane substrates and organocatalysts, thus creating a rare example of acylsilane α-alkylation with a chiral guanidine catalyst, which afforded products in good yields and high stereoselectivity. The corresponding adducts described here have also been demonstrated to be useful in the synthesis