28489-52-3Relevant academic research and scientific papers
Syntheses of Pyrroles, Pyridines, and Ketonitriles via Catalytic Carbopalladation of Dinitriles
Qi, Linjun,Li, Renhao,Yao, Xinrong,Zhen, Qianqian,Ye, Pengqing,Shao, Yinlin,Chen, Jiuxi
, p. 1097 - 1108 (2020/01/22)
The first example of the Pd-catalyzed addition of organoboron reagents to dinitriles, as an efficient means of preparing 2,5-diarylpyrroles and 2,6-diarylpyridines, has been discussed here. Furthermore, the highly selective carbopalladation of dinitriles with organoboron reagents to give long-chain ketonitriles has been developed as well. Based on the broad scope of substrates, excellent functional group tolerance, and use of commercially available substrates, the Pd-catalyzed addition reaction of arylboronic acid and dinitriles is expected to be significant in future synthetic procedures.
NNN-Ruthenium Catalysts for the Synthesis of Pyridines, Quinolines, and Pyrroles by Acceptorless Dehydrogenative Condensation
Deng, Danfeng,Hu, Bowen,Yang, Min,Chen, Dafa
, p. 2386 - 2394 (2018/07/31)
The bidentate ruthenium complex (HO-C5H3N-CO-C5H3N-C5H4N)Ru(CO)2Cl2 (2) could transform to a tridentate product (HO-C5H3N-CO-C5H3N-C5H4N)Ru(CO)Cl2 (3), which further reacted with CH3ONa in the presence of PPh3 to convert to two complexes [(OC5H3N-CO-C5H3N-C5H4N)Ru(PPh3)2(CO)]Cl- (4) and [(OC5H3N-CO-C5H3N-C5H4N)Ru(PPh3)(CO)Cl] (5), via -OH deprotonation. The catalytic coupling cyclizations of secondary alcohols with amino alcohols were investigated, and complex 3 exhibited the highest activity. The coupling reactions proceeded in air with only 0.2 mol % catalyst loading and had a broad scope for the synthesis of pyridines, quinolones, and pyrroles.
Ruthenium-catalyzed decarboxylative and dehydrogenative formation of highly substituted pyridines from alkene-tethered isoxazol-5(4H)-ones
Okamoto, Kazuhiro,Sasakura, Kohei,Shimbayashi, Takuya,Ohe, Kouichi
supporting information, p. 988 - 990 (2016/08/13)
A ruthenium-catalyzed reaction of alkene-tethered isoxazol-5(4H)-ones affording pyridines has been developed. Di-, tri-, and tetrasubstituted pyridines were obtained from various isoxazolones in good yields.
One-pot synthesis of symmetrical 2,6-diarylpyridines via palladium/copper-catalyzed sequential decarboxylative and direct C-H arylation
Ma, Zhiyong,Liu, Hailong,Zhang, Chunchun,Zheng, Xueli,Yuan, Maolian,Fu, Haiyan,Li, Ruixiang,Chen, Hua
supporting information, p. 1143 - 1148 (2015/04/22)
A palladium(II)/copper oxide (Cu2O)-catalyzed one-pot decarboxylative and direct C-H arylation of 2-picolinic acid with aryl bromides has been developed. Various aryl bromides have been shown to be efficient coupling partners in the presence of dimethyl sulfate, furnishing symmetrical 2,6-diarylpyridines in moderate to good yields.
Heteroaromatic synthesis via olefin cross-metathesis: Entry to polysubstituted pyridines
Donohoe, Timothy J.,Basutto, Jose A.,Bower, John F.,Rathi, Akshat
, p. 1036 - 1039 (2011/04/27)
The olefin cross-metathesis reaction provides a rapid and efficient method for the synthesis of α,β-unsaturated 1,5-dicarbonyl derivatives which then serve as effective precursors to mono-tetrasubstituted pyridines. Manipulation of the key 1,5-dicarbonyl intermediate allows access to pyridines with a wide range of substitution patterns. An extension of this methodology facilitates the preparation of pyridines embedded within macrocycles, as exemplified by an efficient synthesis of (R)-(+)-muscopyridine. High levels of regiocontrol, short reaction sequences, and facile substituent variation are all notable aspects of this methodology.(Figure Presented)
Mn(III)-mediated formal [3+3]-annulation of vinyl azides and cyclopropanols: A divergent synthesis of azaheterocycles
Wang, Yi-Feng,Toh, Kah Kah,Ng, Eileen Pei Jian,Chiba, Shunsuke
supporting information; experimental part, p. 6411 - 6421 (2011/06/19)
Mn(III)-mediated formal [3+3]-annulation has been developed using readily available vinyl azides and cyclopropanols with a wide range of substituents. Vinyl azides were successfully applied as a three-atom unit including one nitrogen to prepare pyridines and σ-lactams by the reactions with monocyclic cyclopropanols as well as to construct 2-azabicyclo[3.3.1] and 2-azabicyclo[4.3.1] frameworks with bicyclic cyclopropanols, bicyclo[3.1.0]hexan-1-ols, and bicyclo[4.1.0]heptan-1-ols. These reactions were initiated by a radical addition of β-carbonyl radicals, generated by the one-electron oxidation of cyclopropanols with Mn(III), to vinyl azides to give iminyl radicals, which cyclized with the intramolecular carbonyl groups. In addition, application of the present methodology to a synthesis of the quaternary indole alkaloid, melinonine-E, was accomplished.
Mn(III)-mediated reactions of cyclopropanols with vinyl azides: Synthesis of pyridine and 2-azabicyclo[3.3.1]non-2-en-1-ol derivatives
Wang, Yi-Feng,Chiba, Shunsuke
supporting information; experimental part, p. 12570 - 12572 (2010/01/30)
(Chemical Equation Presented) A Mn(III)-mediated divergent synthesis of substituted pyridines and 2-azabicyclo[3.3.1]non-2-en-1-ol derivatives was exploited using readily available vinyl azides and cyclopropanols with a wide range of substituents. In short, the reactions of vinyl azides with monocyclic cyclopropanol provided pyridines in the presence of Mn(acac)3 (1.7 equiv), whereas those with bicyclic cyclopropanols led to the formation of 2-azabicyclo[3.3.1]non-2-en-1-ol derivatives using a catalytic amount of Mn(acac)3. These reactions may be initiated by a radical addition of β-keto radicals, generated by the one-electron oxidation of cyclopropanols, to vinyl azides to give iminyl radicals, which would cyclize with the intramolecular carbonyl groups. In addition, versatile transformations of 2-azabicyclo[3.3.1] non-2-en-1-ol to 2-azabicyclo[3.3.1]nonane or -non-2-nen frameworks were developed.
A kinetic study of the thermolysis of n-crotyl substituted 1,2,4-triazoles
Carlsen,Jorgensen
, p. 1135 - 1139 (2007/10/03)
A kinetic study of the thermolysis of 4-crotyl-3,5-diphenyl-4H-1,2,4-triazole (1) in a melt of the neat compound was performed at temperatures in the range of 260-350 °C. The main products formed were 1-crotyl-3,5-dipheny1-1H-1,2,4-triazole (3) and 1-(1-methylallyl)-3,5-diphenyl-1H-1,2,4-triazole (4) together with 3-methyl-2,6-diphenylpyridine (2) and 3,5-diphenyl-1,2,4-triazole (5). Products 2 and 5 were both formed preferentially from 3 and 4. In the melt was observed first order kinetics. Activation parameters for formation of 3 and 4 were determined. Product 3: E(a) = 95 kJ/mole. Product 4: E(a) = 145 kJ/mole.
Thermolyses of 1,1-dimethyl-2-pyrazolinium fluoborates - Evidence for spiro--1-aza-1,4,6-octatrienyl cation
Subramaniam, Girija,Fishel, Derry L
, p. 172 - 176 (2007/10/02)
Thermolyses of 3-aryl-1,1-dimethyl-2-pyrazolinium fluoborates give an isomeric mixture of 3-aryl-1-methylpyrazole and 5-aryl-1-methylpyrazole as major products in complete contrast to the corresponding acyclic analogs. 2,6-Diaryl-3-methylpyridines were isolated only in trace quantities.The probable reasons for this unique behaviour was explored using semi-empirical calculations, non-kinetic methods and radiolabelling experiments.A pathway was proposed.
