92-07-9Relevant articles and documents
Use of highly reactive, versatile and air-stable palladium-phosphinous acid complex [(t-Bu)2P(OH)]2PdCl2 (POPd) as a catalyst for the optimized Suzuki-Miyaura cross-coupling of less reactive heteroaryl chlorides and arylboronic acids
Khanapure, Subhash P.,Garvey, David S.
, p. 5283 - 5286 (2004)
Using highly reactive air-stable palladium-phosphinous acid complex [(t-Bu)2P(OH)]2PdCl2 (POPd) as a catalyst, synthesis of heteroaryl-aryl cross-coupled products via palladium-catalyzed Suzuki-Miyaura coupling of less reactive substituted 3-chloropyridines with arylboronic acids was achieved in high yields.
Selective Synthesis of Substituted Pyridines and Pyrimidines through Cascade Annulation of Isopropene Derivatives
Chen, Lu,He, Runfa,Huang, Yubing,Li, Jiaming,Li, Jian,Li, Yibiao,Liu, Jiasheng,Liu, Yang
supporting information, p. 1620 - 1625 (2022/03/14)
Diverse substituted pyridines and pyrimidines with high selectivity were obtained using a concise and efficient protocol developed herein. The reaction proceeds via metal-free cascade annulation of isopropene derivatives. Using isopropene derivatives as C3 synthons, NH4I as the “N” source, and formaldehyde or dimethyl sulfoxide as the carbon source, this reaction realizes the efficient formation of intermolecular C-N and C-C bonds.
Pd Reaction Intermediates in Suzuki-Miyaura Cross-Coupling Characterized by Mass Spectrometry
Chen, Xingshuo,Wei, Zhenwei,Huang, Kai-Hung,Uehling, Mycah,Wleklinski, Michael,Krska, Shane,Makarov, Alexey A.,Nowak, Timothy,Cooks, R. Graham
, (2022/02/09)
Palladium-catalyzed Suzuki-Miyaura (SM) coupling is widely utilized in the construction of carbon-carbon bonds. In this study, nanoelectrospray ionization mass spectrometry (nanoESI-MS) is applied to simultaneously monitor precatalysts, catalytic intermediates, reagents, and products of the SM cross-coupling reaction of 3-Br-5-Ph-pyridine and phenylboronic acid. A set of Pd cluster ions related to the monoligated Pd (0) active catalyst is detected, and its deconvoluted isotopic distribution reveals contributions from two neutral molecules. One is assigned to the generally accepted Pd(0) active catalyst, seen in MS as the protonated molecule, while the other is tentatively assigned to an oxidized catalyst which was found to increase as the reaction proceeds. Oxidative stress testing of a synthetic model catalyst 1,5-cyclooctadiene Pd XPhos (COD?Pd-XPhos) performed using FeCl3 supported this assignment. The formation and conversion of the oxidative addition intermediate during the catalytic cycle was monitored to provide information on the progress of the transmetalation step.
Base-promoted one-pot synthesis of pyridine derivatives via aromatic alkyne annulation using benzamides as nitrogen source
Ashiq, Muhammad Naeem,Hua, Ruimao,Iqbal, Muhammad Asif,Mehmood, Hina
supporting information, (2021/11/08)
In the presence of Cs2CO3, the first simple, efficient, and one-pot procedure for the synthesis of 3,5-diaryl pyridines via a variety of aromatic terminal alkynes with benzamides as the nitrogen source in sulfolane is described. The formation of pyridine derivatives accompanies the outcome of 1,3-diaryl propenes, which are also useful intermediates in organic synthesis. Thus, pyridine ring results from a formal [2+2+1+1] cyclocondensation of three alkynes with benzamides, and one of the alkynes provides one carbon, whilst benzamides provide a nitrogen source only. A new transformation of alkynes as well as new utility of benzamide are found in this work.
Two C=C Bond Participation in Annulation to Pyridines Based on DMF as the Nonadjacent N and C Atom Donors
Su, Miao-Dong,Liu, Hai-Ping,Cao, Zhong-Zhong,Liu, Yufeng,Li, Hui,Nie, Zhi-Wen,Yang, Tong-Lin,Luo, Wei-Ping,Liu, Qiang,Guo, Can-Cheng
, p. 13446 - 13453 (2021/10/12)
Two C=C bond participation in annulation to pyridines using N,N-dimethylformamide (DMF) as the N1 and C4 synthons has been carried out. In this reaction, DMF contributed one N atom and one C atom to two disconnected positions of pyridine ring, with no need for an additional nitrogen source. Two C=C bonds in two molecules of substituted styrenes offered four carbon atoms in the presence of iodine and persulfate. With the optimized conditions in hand, both symmetric and unsymmetric diaryl-substituted pyridines were obtained in useful yields. On the basis of relevant literature and a series of control experimental results, a possible mechanism was proposed in this work, which may demonstrate how DMF provides both N1 and C4 sources.
Method for constructing 3,5-disubstituted pyridine from aryl ethylene and N,N-dimethylformamide through cyclization reaction
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Paragraph 0084; 0085; 0086; 0087; 0088, (2020/09/09)
The invention discloses a method for constructing 3,5-disubstituted pyridine from aryl ethylene and N,N-dimethylformamide through a cyclization reaction. The method comprises carrying out cyclizationon the aryl ethylene, the N,N-dimethylformamide and peroxydisulfate under the catalytic action of iodized salt to obtain the 3,5-disubstituted pyridine. According to the method, iodine salt is utilized to catalyze one-step oxidative cyclization of the aryl ethylene and DMF to synthesize 3,5-disubstituted pyridine, and the method has the advantages of low cost of raw materials and catalysts, mild reaction conditions, capability of obtaining symmetric 3,5-disubstituted pyridine with high selectivity and high yield and the like.
Method for constructing 3,5-disubstituted pyridine by utilizing mixed styrene derivative and N,N-dimethylformamide
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Paragraph 0101-0107, (2020/08/27)
The invention discloses a method for constructing 3,5-disubstituted pyridine by utilizing mixed styrene derivative and N,N-dimethylformamide. The method comprises the following step: subjecting the mixed styrene derivative, N,N-dimethylformamide and peroxydisulfate to a cyclization reaction under the catalytic action of iodized salt so as to obtain symmetrical and asymmetrical mixed 3,5-disubstituted pyridine products at the same time. According to the method, 3,5-disubstituted pyridine is synthesized from the mixed styrene derivative and DMF through one-step oxidative cyclization under the catalysis of iodate; and the method has the advantages of low raw material and catalyst cost, mild reaction conditions, capability of realizing high-yield preparation of the symmetrical and asymmetrical3,5-disubstituted pyridine products at the same time and the like.
Pd-Catalyzed Decarboxylation and Dual C(sp3)-H Functionalization Protocols for the Synthesis of 2,4-Diarylpyridines
Gujjarappa, Raghuram,Vodnala, Nagaraju,Kumar, Mohan,Malakar, Chandi C.
, p. 5005 - 5020 (2019/04/25)
The Pd-catalyzed decarboxylation and dual C(sp3)-H bond functionalization approaches have been described for the preparation of symmetrical and unsymmetrical 2,4-diarylpyridines. The developed transformations were realized using nonactivated aromatic ketones and amino acids as C-N sources. The efficacy of the catalyst and reagent combination drives the transformation toward the formation of desired products with high yields and selectivity. The described reaction conditions have seduced the self-reaction of phenylalanine via [2 + 2 + 2] cycloaddition and minimized the formation of 3,5-phenylpyridine as a side product, whereas using glycine as a C-N source, the corresponding 2,6-diarylpyridines were formed as minor products.
Photoredox C-F Quaternary Annulation Catalyzed by a Strongly Reducing Iridium Species
Dai, Peng,Ma, Junyu,Huang, Wenhao,Chen, Wenxin,Wu, Na,Wu, Shengfu,Li, Ying,Cheng, Xu,Tan, Renxiang
, p. 802 - 806 (2018/02/14)
We report a fac-Ir(ppy)3?-IrII-IrIII photocatalytic cycle involving t-BuOK as the terminal reductant in a visible-light-induced sp2 C-F quaternary annulation reaction that proceeds in yields up to 98%. Because of the high activity of the IrII(ppy)3 catalyst, even at a loading of 50 ppm, the annulation reaction was able to compete with an uncatalyzed nucleophilic aromatic substitution reaction. The annulation reaction was stereoconvergent, and an annulated product was synthesized with complete retention of enantiomeric excess.
Olefin Cyclopropanation by Radical Carbene Transfer Reactions Promoted by Cobalt(II)/Porphyrinates: Active-Metal-Template Synthesis of [2]Rotaxanes
Alcantara, Arthur F. P.,Fontana, Liniquer A.,Rigolin, Vitor H.,Andrade, Yuri F. S.,Ribeiro, Marcos A.,Barros, Wdeson P.,Ornelas, Catia,Megiatto, Jackson D.
supporting information, p. 8979 - 8983 (2018/07/24)
A CoII/porphyrinate-based macrocycle in the presence of a 3,5-diphenylpyridine axial ligand functions as an endotopic ligand to direct the assembly of [2]rotaxanes from diazo and styrene half-threads, by radical-carbene-transfer reactions, in excellent 95 % yield. The method reported herein applies the active-metal-template strategy to include radical-type activation of ligands by the metal-template ion during the organometallic process which ultimately yields the mechanical bond. A careful quantitative analysis of the product distribution afforded from the rotaxane self-assembly reaction shows that the CoII/porphyrinate subunit is still active after formation of the mechanical bond and, upon coordination of an additional diazo half-thread derivative, promotes a novel intercomponent C?H insertion reaction to yield a new rotaxane-like species. This unexpected intercomponent C?H insertion illustrates the distinct reactivity brought to the CoII/porphyrinate catalyst by the mechanical bond.
