Well‐Defined, Versatile and Recyclable Half‐Sandwich Nickelacarborane Catalyst for Selective Carbene‐Transfer Reactions
作者:Linghua Wang、Saima Perveen、Yizhao Ouyang、Shuai Zhang、Jiao Jiao、Gang He、Yong Nie、Pengfei Li
DOI:10.1002/chem.202005014
日期:2021.3.26
accessible nickel(II)‐based complexes have been rarely used. Herein, an air‐stable nickel(II)‐carborane complex is reported as a well‐defined, versatile and recyclable catalyst for selective carbene transfer reactions with low catalyst loading undermildconditions. This catalyst is effective for several types of reactions including diastereoselective cyclopropanation, epoxidation, selective X−H insertions
Silica-supported HClO<sub>4</sub> promotes catalytic solvent- and metal-free O–H insertion reactions with diazo compounds
作者:Rafael Douglas C. Gallo、Antonio C. B. Burtoloso
DOI:10.1039/c8gc02574f
日期:——
employing rhodium acetate dimer, this method uses eco-friendly silica-supported HClO4 as the catalyst. Only 0.3 mol% of this Brønsted acid catalyst, that can also be recycled several times, is necessary to guarantee very good yields (up to 97%) in the O–H insertion reactions. Reaction set-up is simple and permitted the preparation of forty-three α-hydroxy and α-alkoxy esters/ketones in just 1 h and at room
A facile synthesis of a wide variety of tert-butyl ethers and tert-butyl ester derivatives under mild conditions is described. Alcohols etherified with tert-butyl methylether as tert-butyl source and solvent, in the presence of sulfuric acid. Many amino acid tert-butyl esters have been synthesized by this procedure. The reaction is simple, inexpensive, easily scaled up, and proceeds without observable