scholarly journals Highly efficient synthesis of 2-substituted benzo[b]furan derivatives from the cross-coupling reactions of 2-halobenzo[b]furans with organoalane reagents

Synthesis ◽  
2021 ◽  
Author(s):  
chang wen ◽  
Qing Han Li ◽  
Chuan Wu ◽  
ruiqiang Luo ◽  
Feng Chen

A highly efficient and simple route for the synthesis of 2-substituted benzo[b]furans has been developed by Palladium catalyzed the cross-coupling reaction of 2-halobenzo[b]furans with aryl, alkynyl and alkylaluminum reagents. Various 2-aryl, 2-alkynyl and 2-alkyl substituted benzo[b]furans derivatives can be obtained with 23-97% isolated yields using 2-3 mol% PdCl2/ 4-6 mol% XantPhos as the catalyst under mild reaction conditions. The aryls bearing electron-donating or electron-withdrawing groups in 2-halobenzo[b]furans gave products in 40-97% isolated yields. In addition, aluminum reagents containing thienyl, furanyl trimethylsilanyl and benzyl groups worked efficiently with 2-halobenzo[b]furans as well, and three bioactive molecules with 2-substituted benzo[b]furan skeleton were synthesized. Furthermore, the broad substrates scope and the typical maintenance of vigorous efficiency on gram scale make this protocol a potentially practical method to synthesize 2-substituted benzo[b]furans derivatives. On the basis of the experimental results, a possible catalytic cycle has been proposed.

Synthesis ◽  
2020 ◽  
Vol 52 (16) ◽  
pp. 2387-2394 ◽  
Author(s):  
Jorge A. Cabezas ◽  
Natasha Ferllini

A regiospecific palladium-catalyzed cross-coupling reaction using the operational equivalent of the dianion 1,3-dilithiopropyne, with aromatic iodides is reported. This reaction gives high yields of 1-propyn-1-yl-benzenes and 2-(propyn-1-yl)thiophenes in the presence of catalytic amounts of palladium(0) or (II) and stoichiometric amounts of copper iodide. No terminal alkyne or allene isomers were detected. Reaction conditions were very mild and several functional groups were tolerated.


RSC Advances ◽  
2016 ◽  
Vol 6 (111) ◽  
pp. 109296-109300 ◽  
Author(s):  
Xian Wang ◽  
Zhenhua Wang ◽  
Zunyuan Xie ◽  
Guofang Zhang ◽  
Weiqiang Zhang ◽  
...  

1,3-Yones as σ-, π-electron donating ligands significantly accelerated the cross-coupling reactions of aryl iodides with terminal alkynes, in which as low as 0.1 to 1 mol% of CuI were efficiently activated.


2017 ◽  
Vol 13 ◽  
pp. 2122-2127 ◽  
Author(s):  
James R Vyvyan ◽  
Courtney A Engles ◽  
Scott L Bray ◽  
Erik D Wold ◽  
Christopher L Porter ◽  
...  

Several Hiyama cross-coupling reactions of oxasilacycloalkenes and aryl iodides are described that produce trisubstituted Z-styrenes in moderate to excellent yields. Both electron-rich and electron-poor aryl iodides are tolerated in the cross-coupling reaction. The oxasilacycloalkene coupling partners were prepared by ruthenium-catalyzed intramolecular anti-hydrosilylation of alkynols. One of the cross-coupling products was converted to a 1-benzoxocane, albeit in low yield, using an intramolecular Buchwald–Hartwig etherification. The cyclic ether produced contains the carbon skeleton of heliannuol A.


2012 ◽  
Vol 8 ◽  
pp. 2004-2018 ◽  
Author(s):  
Rajendra Surasani ◽  
Dipak Kalita ◽  
A V Dhanunjaya Rao ◽  
K B Chandrasekhar

Simple and efficient procedures for palladium-catalyzed cross-coupling reactions of N-substituted 4-bromo-7-azaindole (1H-pyrrole[2,3-b]pyridine), with amides, amines, amino acid esters and phenols through C–N and C–O bond formation have been developed. The C–N cross-coupling reaction of amides, amines and amino acid esters takes place rapidly by using the combination of Xantphos, Cs2CO3, dioxane and palladium catalyst precursors Pd(OAc)2/Pd2(dba)3. The combination of Pd(OAc)2, Xantphos, K2CO3 and dioxane was found to be crucial for the C–O cross-coupling reaction. This is the first report on coupling of amides, amino acid esters and phenols with N-protected 4-bromo-7-azaindole derivatives.


Synlett ◽  
2017 ◽  
Vol 29 (03) ◽  
pp. 330-335 ◽  
Author(s):  
Zheng-Jun Quan ◽  
Xi-Cun Wang ◽  
Ming-Xia Liu ◽  
Hai-Peng Gong

Dihetaryl disulfides were used as electrophiles in a palladium-catalyzed carbon–carbon cross-coupling reaction with arylsilanes to ­realize a Hiyama-type reaction. This unique transformation shows high reactivity, excellent functional-group tolerance, and mild reaction conditions, making it an attractive alternative to conventional cross-coupling approaches for carbon−carbon bond construction.


2018 ◽  
Vol 2 (3) ◽  
pp. 591-596 ◽  
Author(s):  
Shuichi Suzuki ◽  
Fumiya Nakamura ◽  
Takeshi Naota

We have developed an efficient synthetic method for (nitronyl nitroxide)-substituted π-electronic compounds via palladium-catalyzed cross-coupling reactions with a zinc complex of the parent nitronyl nitroxide radical anion.


2020 ◽  
Author(s):  
Chet Tyrol ◽  
Nang Yone ◽  
Connor Gallin ◽  
Jeffery Byers

By using an iron-based catalyst, access to enantioenriched 1,1-diarylakanes was enabled through an enantioselective Suzuki-Miyaura crosscoupling reaction. The combination of a chiral cyanobis(oxazoline) ligand framework and 1,3,5-trimethoxybenzene additive were essential to afford high yields and enantioselectivities in cross-coupling reactions between unactivated aryl boronic esters and a variety of benzylic chlorides, including challenging ortho-substituted benzylic chloride substrates. Mechanistic investigations implicate a stereoconvergent pathway involving carbon-centered radical intermediates.


Author(s):  
Jonathon Moir

Pharmaceuticals and drugs have become an indispensable part of human life. Presently, a myriad of different drugs are available for a variety of mental and physical health concersn. The synthesis of these drugs, however, remains an elusive and often difficult aspect of the industry. The importance of chirality, or "handedness", in the synthesis of natural products is paramount, as any given pair of enantiomers can have widely differing physiological effects. As such, the ability to control the enantioselectivity of a reaction is of the utmost importance. One example of a facile method used to form carbon-carbon bonds is the Suzuki-Miyaura cross-coupling reaction. Not only is this reaction effective at coupling primary organoboronic esters with organohalides, but recent work in the Crudden group in the Department of Chemistry has revealed an effective method of also cross-couplingchiral secondary organoboronic esters with good retention of stereochemistry. This work, the first of its kind, is crucial in developing single-handed natural products for a wide array of applications, including applications in the pharmaceutical industry. The end result is safer and more effective drugs for distribution to the general public. To expand the scope of this project, new substrates are currently being synthesized for cross-coupling applications. The overall goal is to improve upon current methodologies, while helping to meet the industrial and academic needs of the future.  


Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 652 ◽  
Author(s):  
Monika Olesiejuk ◽  
Agnieszka Kudelko ◽  
Marcin Swiatkowski ◽  
Rafal Kruszynski

New derivatives of 4-alkyl-3,5-diaryl-4H-1,2,4-triazole were synthesized utilizing the Suzuki cross-coupling reaction. The presented methodology comprises of the preparation of bromine-containing 4-alkyl-4H-1,2,4-triazoles and their coupling with different commercially available boronic acids in the presence of ionic liquids or in conventional solvents. The obtained compounds were tested for their luminescence properties.


RSC Advances ◽  
2014 ◽  
Vol 4 (69) ◽  
pp. 36437-36443 ◽  
Author(s):  
Zhenhong Guan ◽  
Buyi Li ◽  
Guoliang Hai ◽  
Xinjia Yang ◽  
Tao Li ◽  
...  

Microporous polymers with built-in triphenylphosphine palladium exhibit highly efficient catalytic activity for cross-coupling reactions of benzyl chloride under mild conditions.


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