Stereoselective preparation of Z-trisubstituted alkylidene cyclic carbonates via palladium-catalyzed carboncarbon bond formation
摘要:
Alkylidene cyclic carbonates bearing a Z-trisubstituted exocyclic double bond have been stereoselectively prepared in good yields for the first time from methylene cyclic carbonates, resistant to the classical Heck reaction, on treatment with aryl iodides, CF3CO2Ag and palladium catalyst, under conditions which tolerate (sp(2))C-Br bonds. (C) 2000 Elsevier Science Ltd. All rights reserved.
Palladium-Catalyzed Arylcarboxylation of Propargylic Alcohols with CO<sub>2</sub> and Aryl Halides: Access to Functionalized α-Alkylidene Cyclic Carbonates
trans-oxopalladation of the C≡Cbond by an ArPdX species, and a reductive elimination procedure afforded a series of functionalized α-alkylidene cyclic carbonates in moderate to excellent yields. Notably, the configuration of these tetrasubstituted olefins was dominated by the trans-oxopalladation step where the aryl group derived from ArX is located trans to the oxygen attached in the doublebond. This protocol
Effective Guanidine-Catalyzed Synthesis of Carbonate and Carbamate Derivatives from Propargyl Alcohols in Supercritical Carbon Dioxide
作者:Nicola Della Ca'、Bartolo Gabriele、Giuseppe Ruffolo、Lucia Veltri、Tito Zanetta、Mirco Costa
DOI:10.1002/adsc.201000607
日期:2011.1.10
The reactions of propargyl alcohols with carbondioxide in supercriticalcarbondioxide or in acetonitrile with gaseous carbondioxide in the presence of organic bases as catalysts have been examined. Bicyclic guanidines are effective catalysts for the formation of α‐methylene cyclic carbonates under mild reaction conditions. Oxoalkyl carbonates, oxoalkyl carbamates or α‐methyleneoxazolidinones are
Alkoxide-functionalized imidazolium betaines for CO<sub>2</sub> activation and catalytic transformation
作者:Yan-Bo Wang、Dong-Sheng Sun、Hui Zhou、Wen-Zhen Zhang、Xiao-Bing Lu
DOI:10.1039/c3gc42346h
日期:——
Alkoxide-functionalized imidazolium betaines (AFIBs) functioned as organocatalysts for the coupling of CO2 with propargylic alcohols to give valuable cyclic carbonates via AFIB-CO2 adducts.
ne, copper iodide could efficiently catalyze the coupling of internal propargylicalcohols with carbondioxide to afford the corresponding α‐alkylidene cyclic carbonates in moderate to excellent yields. Moreover, we have developed a new and versatile protocol for the chemo‐ and stereoselective synthesis of a wide range of (E)‐α‐iodoalkylidene cyclic carbonates from carbondioxide, propargylic alcohols
A Bifunctional Tungstate Catalyst for Chemical Fixation of CO<sub>2</sub>at Atmospheric Pressure
作者:Toshihiro Kimura、Keigo Kamata、Noritaka Mizuno
DOI:10.1002/anie.201203189
日期:2012.7.2
No pressure: A simple monomeric tungstate, [WO4]2−, serves as a highly efficient homogeneous catalyst for various transformations of CO2 at atmosphericpressure. The tungsten‐oxo moiety activates CO2 and the substrate simultaneously. The catalyst system is high yielding and applicable to a wide range of substrates such as amines (see scheme), 2‐aminobenzonitriles, and propargylic alcohols.