catalysed oxidative coupling reaction of formamides with β-keto esters and 2-carbonyl-substituted phenols successfully proceeded through directC–Hbondactivation of formamides. The corresponding carbamates were formed with high stereoselectivity under mild reaction conditions. This protocol was successfully applied to the synthesis of three novel halogenated carbamates and a carbaryl insecticide derivative
Copper-Catalyzed Oxidative CO Coupling by Direct CH Bond Activation of Formamides: Synthesis of Enol Carbamates and 2-Carbonyl-Substituted Phenol Carbamates
Formamide CH bondactivation has been achieved under oxidative conditions, using a copper catalyst and tert‐butyl hydroperoxide (TBHP) as the external oxidant (see scheme). This oxidative coupling of a range of dialkyl formamides provides an easy, phosgene‐free route for the selective synthesis of Z‐enol carbamates and 2‐carbonyl‐substituted phenol carbamates in high yields.
Anchoring of a Copper(II)–Schiff Base Complex onto Silica-Coated Ferrite Nanoparticles: A Magnetically Separable Catalyst for Oxidative C–O Coupling by Direct C(sp2)–H and C(sp3)–H Bond Activation
A novel catalyst consisting of a Schiff base-copper complex on surface-modified silica-coated ferrite nanoparticles was been prepared and used for oxidative C-O cross-coupling reactions of 1,3-dicarbonyl compounds with formamides for the synthesis of enol carbamates. The new catalyst has also been used for esterification of alkylbenzenes with cyclic ethers.
Copper nanoparticles on charcoal: an effective nanocatalyst for the synthesis of enol carbamates and amides via an oxidative coupling route
The catalytic activity of copper nanoparticles on charcoal (Cu/C) was investigated as an environmentally friendly heterogeneous catalyst for the synthesis of enol carbamates and amides via the oxidative coupling of N,N-dialkyl formamides with 1,3-dicarbonyl compounds and aromatic aldehydes with amine hydrochloride salts, respectively. Various enol carbamates and amides were synthesized in moderate to good yields using this method. Moreover, the catalyst could be recovered and subsequently reused in further reactions. (C) 2015 Elsevier Ltd. All rights reserved.
CuO nanoparticles supported on α-Fe2O3-modified CNTs: a magnetically separable catalyst for oxidative C–O coupling of formamides with 1,3-dicarbonyl compounds
作者:Dariush Saberi、Akbar Heydari
DOI:10.1016/j.tetlet.2013.05.113
日期:2013.8
Oxidative coupling of formamides with 1,3-dicarbonyl compounds to prepare enol carbamates was effected in the presence of CuO nanoparticles supported on alpha-Fe2O3-modified carbon nanotubes (CNTs@alpha-Fe2O3@CuO) as an environmentally friendly heterogeneous catalyst. The simple preparation, and the ability to be recycled and magnetically separated are salient features of this catalytic system. (C) 2013 Elsevier Ltd. All rights reserved.