N-Heterocyclic carbene copper-catalyzed direct alkylation of terminal alkynes with non-activated alkyl triflates

2017 ◽  
Vol 53 (29) ◽  
pp. 4124-4127 ◽  
Author(s):  
Liqun Jin ◽  
Wangfang Hao ◽  
Jianeng Xu ◽  
Nan Sun ◽  
Baoxiang Hu ◽  
...  

(NHC)-Cu-catalyzed C(sp)–C(sp3) bond formation has been successfully achieved under mild conditions.

2017 ◽  
Vol 53 (44) ◽  
pp. 6013-6016 ◽  
Author(s):  
Gang Xiong ◽  
Bing Yu ◽  
Jie Dong ◽  
Ying Shi ◽  
Bin Zhao ◽  
...  

We report here two cluster-based MOFs I and II as excellent heterogeneous catalysts in the carboxylation reactions of CO2 and terminal alkynes under 1 atm and mild conditions. This is the first time for MOFs materials to catalyze this type of reactions.


2020 ◽  
Vol 02 (03) ◽  
pp. e128-e132
Author(s):  
Shao-Zheng Guo ◽  
Zhi-Qun Yu ◽  
Wei-Ke Su

AbstractThe development of highly efficient C–C bond formation methods for the synthesis of ethyl 2-(2,4-dichloro-5-fluorobenzoyl)-3-(dimethylamino)acrylate 1 in continuous flow processes has been described, which is based on the concept of rapid and efficient activation of carboxylic acid. 2,4-Dichloro-5-fluorobenzoic acid is rapidly converted into highly reactive 2,4-dichloro-5-fluorobenzoyl chloride by treating with inexpensive and less-toxic solid bis(trichloromethyl)carbonate. And then it rapidly reacts with ethyl 3-(dimethylamino)acrylate to afford the desired 1. This process can be performed under mild conditions. Compared with the traditional tank reactor process, less raw material consumption, higher product yield, less reaction time, higher operation safety ensured by more the environmentally friendly procedure, and process continuity are achieved in the continuous-flow system.


2021 ◽  
pp. 174751982110325
Author(s):  
Yan Xiao ◽  
Jiyu Gao ◽  
Peng Chen ◽  
Guangliang Chen ◽  
Zicheng Li ◽  
...  

A series of symmetrical 1,4-disubstituted buta-1,3-diynes is prepared with excellent yields (up to 95%) through homocoupling of terminal alkynes catalyzed by a copper salt under solvent-free conditions. This method provides an environmentally friendly process to prepare 1,3-diynes in short reaction times under mild conditions. Furthermore, the method is suitable for a wide substrate scope and has excellent functional group compatibility. The reaction can also be scaled up to gram level.


Reactions of nucleophiles with triosmium carbonyl clusters, especially those containing unsaturated hydrocarbon ligands, are discussed. Attack may be at CO, the metal atoms, at carbon of the organic ligand, or, where there are acidic metal-bound hydrogen atoms, deprotonation to give anionic clusters may occur. New results on the reactions of LiBHEt3 with p3-alkyne clusters of type Os3(CO)10 (RC2R') are considered in the light of the range of possible sites of attack. Protonation of anionic species that are formed gives hydrogenation products with or without the loss of CO. Os3H2(CO)9(RC2R') is usually a minor product, while C-C coupling leads to Os3H(CO)9(CRCR'COH) (in general the major product) and to Os3H(CO)9- (CRCR'CH). With terminal alkynes RC2H H-atom transfer accompanies C-C coupling to give Os3H(CO)9(RC—C =C H 2) in substantial amounts. The initial site of hydride attack (CO, alkyne or metal) is considered in the context of low-temperature 1H n.m.r. results.


Author(s):  
Xingjie Zhang ◽  
Di Qi ◽  
Chenchen Jiao ◽  
Zhiguo Zhang ◽  
Xiaopan Liu ◽  
...  

The direct iminoalkynylation of unactivated olefins with terminal alkynes is achieved for the first time by nickel-catalyzed cascade iminyl-radical cyclization/Sonogashira-type coupling of γ,δ-unsaturated oxime esters under mild conditions. This transformation...


2011 ◽  
Vol 7 ◽  
pp. 338-345 ◽  
Author(s):  
Dhilli Rao Gorja ◽  
K Shiva Kumar ◽  
K Mukkanti ◽  
Manojit Pal

The Pd/C–CuI–PPh3 catalytic system facilitated C–C bond formation between 4-chlorothieno[2,3-d]pyrimidines and terminal alkynes in methanol with high selectivity without generating any significant side products arising from C–O bond formation between the chloro compounds and methanol. A variety of novel 4-alkynylthieno[2,3- d]pyrimidines were prepared via alkynylation of 4-chlorothieno[2,3-d]pyrimidines in good to excellent yields. Some of the compounds synthesized were tested for cytotoxic activity in vitro.


2013 ◽  
Vol 9 ◽  
pp. 1969-1976 ◽  
Author(s):  
Yin-wei Sun ◽  
Qin Xu ◽  
Min Shi

Oxabicyclic alkenes can react with electron-deficient terminal alkynes in the presence of a gold catalyst under mild conditions, affording the corresponding addition products in moderate yields. When using alkynyl esters as substrates, the (Z)-acrylate derivatives are obtained. Using but-3-yn-2-one (ethynyl ketone) as a substrate, the corresponding addition product is obtained with (E)-configuration. The proposed mechanism of these reactions is also discussed.


ChemInform ◽  
2015 ◽  
Vol 46 (7) ◽  
pp. no-no
Author(s):  
Mengru Li ◽  
Yueju Li ◽  
Baozhong Zhao ◽  
Fushun Liang ◽  
Long-Yi Jin

Synthesis ◽  
2018 ◽  
Vol 50 (05) ◽  
pp. 1123-1132 ◽  
Author(s):  
Jürgen Martens ◽  
Torben Schlüter ◽  
Nils Frerichs ◽  
Marc Schmidtmann

This work describes the synthesis of compounds containing thiazolidine and propargylamidic motifs. Their preparation follows a synthetic route containing two multicomponent reactions. First, the Asinger four-component reaction is used to prepare 3-thiazolines and 3-oxazolines. Secondly, these heterocyclic imines are converted into propargylamides by a copper-catalyzed three-component reaction using acyl chlorides and terminal alkynes. The synthetic route is characterized by mild conditions and many functional groups are tolerated. The formation of an unexpected α-alkynoxyamide is also presented.


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