scholarly journals N-Methylphthalimide-substituted benzimidazolium salts and PEPPSI Pd–NHC complexes: synthesis, characterization and catalytic activity in carbon–carbon bond-forming reactions

2016 ◽  
Vol 12 ◽  
pp. 81-88 ◽  
Author(s):  
Senem Akkoç ◽  
Yetkin Gök ◽  
İlhan Özer İlhan ◽  
Veysel Kayser

A series of novel benzimidazolium salts (1–4) and their pyridine enhanced precatalyst preparation stabilization and initiation (PEPPSI) themed palladium N-heterocyclic carbene complexes [PdCl2(NHC)(Py)] (5–8), where NHC = 1-(N-methylphthalimide)-3-alkylbenzimidazolin-2-ylidene and Py = 3-chloropyridine, were synthesized and characterized by means of 1H and 13C{1H} NMR, UV–vis (for 5–8), ESI-FTICR-MS (for 2, 4, 6–8) and FTIR spectroscopic methods and elemental analysis. The synthesized compounds were tested in Suzuki–Miyaura cross-coupling (for 1–8) and arylation (for 5–8) reactions. As catalysts, they demonstrated a highly efficient route for the formation of asymmetric biaryl compounds even though they were used in very low loading. For example, all compounds displayed good catalytic activity for the C–C bond formation of 4-tert-butylphenylboronic acid with 4-chlorotoluene.

2020 ◽  
Vol 7 (1) ◽  
pp. 23-39 ◽  
Author(s):  
Kantharaju Kamanna ◽  
Santosh Y. Khatavi

Multi-Component Reactions (MCRs) have emerged as an excellent tool in organic chemistry for the synthesis of various bioactive molecules. Among these, one-pot MCRs are included, in which organic reactants react with domino in a single-step process. This has become an alternative platform for the organic chemists, because of their simple operation, less purification methods, no side product and faster reaction time. One of the important applications of the MCRs can be drawn in carbon- carbon (C-C) and carbon-heteroatom (C-X; X = N, O, S) bond formation, which is extensively used by the organic chemists to generate bioactive or useful material synthesis. Some of the key carbon- carbon bond forming reactions are Grignard, Wittig, Enolate alkylation, Aldol, Claisen condensation, Michael and more organic reactions. Alternatively, carbon-heteroatoms containing C-N, C-O, and C-S bond are also found more important and present in various heterocyclic compounds, which are of biological, pharmaceutical, and material interest. Thus, there is a clear scope for the discovery and development of cleaner reaction, faster reaction rate, atom economy and efficient one-pot synthesis for sustainable production of diverse and structurally complex organic molecules. Reactions that required hours to run completely in a conventional method can now be carried out within minutes. Thus, the application of microwave (MW) radiation in organic synthesis has become more promising considerable amount in resource-friendly and eco-friendly processes. The technique of microwaveassisted organic synthesis (MAOS) has successfully been employed in various material syntheses, such as transition metal-catalyzed cross-coupling, dipolar cycloaddition reaction, biomolecule synthesis, polymer formation, and the nanoparticle synthesis. The application of the microwave-technique in carbon-carbon and carbon-heteroatom bond formations via MCRs with major reported literature examples are discussed in this review.


2015 ◽  
Vol 39 (7) ◽  
pp. 5350-5353 ◽  
Author(s):  
Subhash Banerjee

A simple and efficient protocol for selective bis-Michael addition and mono-allylation of active methylene compounds has been demonstrated using ultra-small size (∼5 nm) uncapped cerium oxide nanoparticles (free-CeO2 NPs) as a reusable catalyst in water at room temperature.


RSC Advances ◽  
2015 ◽  
Vol 5 (22) ◽  
pp. 16801-16814 ◽  
Author(s):  
Zhi Guan ◽  
Ling-Yu Li ◽  
Yan-Hong He

This article reviews the hydrolase-catalyzed asymmetric carbon–carbon bond-forming reactions for the preparation of enantiomerically enriched compounds in organic synthesis.


2019 ◽  
Vol 6 (1) ◽  
pp. 69-76
Author(s):  
Km N. Shivhare ◽  
Ibadur R. Siddiqui

Background: A green, recyclable and reusable chitosan catalyst has been utilized for the synthesis of 5-amino-2,3-dihydrobenzo[d]thiazole-4,6-dicarbonitrile and its derivatives. Methods and Results: Three-component reaction protocol incorporates the reaction of aldehydes, malononitrile and rhodanine derivatives. This is examined as an efficient route for the synthesis of dicarbonitriles utilizing a green, biodegradable, environmentally benign, and easily available chitosan catalyst. In the reported protocol, catalyst can be recycled and not any substantial dropping in its catalytic activity during the recycling steps was obtained. Conclusion: A green and environmentally benign, one pot three-component protocol has been illustrated for the synthesis of 5-amino-2,3-dihydrobenzo[d]thiazole-4,6-dicarbonitrile derivatives. Adequately yield products were gained via the natural catalytic approach with the recyclability of the catalyst. The use of chitosan represents this procedure as an attractive substitute for the synthesis of biaryls complex by multicomponent reaction condition.


ChemInform ◽  
1990 ◽  
Vol 21 (43) ◽  
Author(s):  
G. ERKER ◽  
M. AULBACH ◽  
M. MENA ◽  
R. PFAFF ◽  
F. SOSNA

2020 ◽  
Vol 11 (17) ◽  
pp. 4305-4311 ◽  
Author(s):  
Yoshitaka Aramaki ◽  
Naoki Imaizumi ◽  
Mao Hotta ◽  
Jun Kumagai ◽  
Takashi Ooi

Radical–ion pair generation from common Lewis pairs and its application to catalytic carbon–carbon bond formation.


RSC Advances ◽  
2015 ◽  
Vol 5 (76) ◽  
pp. 62179-62193 ◽  
Author(s):  
Amrutha P. Thankachan ◽  
S. Asha ◽  
K. S. Sindhu ◽  
Gopinathan Anilkumar

Enantioselective zinc-catalyzed aldol reactions provide an efficient route for the construction of a wide range of carbon–carbon bond-formation, which are described here.


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