Erbium(III) triflate is a powerfulcatalyst for the acylation of alcohols and phenols. The reaction works well for a large variety of simple and functionalized substrates by using different kinds of acidicanhydrides Ac2O, (EtCO)2O, [(CH3)3CO]2O, Bz2O, and (CF3CO)2O} without isomerisation of chiral centres. Moreover, the catalyst can be easily recycled and reused without significant loss of activity
(2-Fluoroallyl)pyridinium tetrafluoroborates: novel fluorinated electrophiles for Pd-catalyzed allylic substitution
作者:Angelina Yu. Bobrova、Maxim A. Novikov、Yury V. Tomilov
DOI:10.1039/d1ob00567g
日期:——
An efficient two-step approach to 2-fluoroallyl amines was developed that involves the synthesis of (2-fluoroallyl)pyridinium tetrafluoroborates from readily available gem-bromofluorocyclopropanes and the application of the former as novel and stable 2-fluoroallyl electrophiles for Pd-catalyzed allylic substitution.
Hydrogen-bond-assisted transition-metal-free catalytic transformation of amides to esters
作者:Changyu Huang、Jinpeng Li、Jiaquan Wang、Qingshu Zheng、Zhenhua Li、Tao Tu
DOI:10.1007/s11426-020-9883-3
日期:2021.1
interest in synthetic chemistry, biological process and pharmaceutical industry. Transition-metal, luxury ligand or excess base were always vital to the transformation. Here, we developed a transition-metal-free hydrogen-bond-assisted esterification of amides with only catalytic amount of base. The proposed crucial role of hydrogen bonding for assisting esterification was supported by control experiments
[EN] METHOD OF CONVERTING ALCOHOL TO HALIDE<br/>[FR] PROCÉDÉ DE CONVERSION D'UN ALCOOL EN HALOGÉNURE
申请人:UNIV SAARLAND
公开号:WO2016202894A1
公开(公告)日:2016-12-22
The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.
Solvent-Free Esterification of Carboxylic Acids and Alcohols in the Presence of Silphos [PCl<sub>3-n</sub>(SiO<sub>2</sub>)<sub>n</sub>] as a Heterogeneous Phosphine Reagent
Abstract An efficient solvent-free method for the preparation of esters from various aromatic and aliphatic acids with primary, secondary, and tertiary alcohols using a heterogeneous phosphinereagent, silphos [PCl3-n(SiO2)n], in good yields is reported. GRAPHICAL ABSTRACT