63797-37-5Relevant academic research and scientific papers
A new approach to pyridines through the reactions of methyl ketones with 1,2,4-triazines
Wang, Shu-Wen,Guo, Wei-Si,Wen, Li-Rong,Li, Ming
, p. 59218 - 59220 (2015/02/19)
A new route to prepare pyridine derivatives based on inverse electron demand Diels-Alder/retro-Diels-Alder reactions of ketones with 1,2,4-triazines is reported. It is the first time using methyl ketones directly as a dienophile to react with 1,2,4-triazines without enamine intermediates, which is complementary to the classical Boger reaction. This journal is
An efficient synthesis of 3-substituted isoquinoline and pyridine derivatives by gold catalyzed intramolecular cyclization from o-alkynyloximes
Subbarao,Reddy, G. Raveendra,Muralikrishna,Reddy
, p. 1045 - 1050 (2014/08/05)
A one-pot reaction was developed efficiently by AuCl3 catalyzed intramolecular cyclization of aromatic o-alkynyloximes and 2-alkynylcycloalkene- 1-carbaldoximes leading to the formation of isoquinoline and pyridine derivatives with high yields. This methodology has been applied for aromatic as well as aliphatic systems. Aromatic o-alkynyloximes are benzene and naphthalene, whereas electron-donating groups are 4-methoxybenzene, 4-methylbenzene, and 4-methoxy-5-methylbenzene. There are electron-withdrawing groups such as chloro and nitrobenzene o-alkynyl oximes, and the same methodology has been successfully applied to pyridine and piperonal, which is also extended to aliphatic rings such as five-member, six-member, seven-member, and eight-member 2-alkynylcycloalkene-1-carbaldoximes.
Diverse reactions of 1,4-dilithio-1,3-dienes with nitrites: Facile access to tricyclic Δ1-bipyrrolines, multiply substituted pyridines, siloles, and (Z,Z)-dienylsilanes by tuning of substituents on the butadienyl skeleton
Yu, Nan,Wang, Congyang,Zhao, Fei,Liu, Lantao,Zhang, Wen-Xiong,Xi, Zhenfeng
experimental part, p. 5670 - 5679 (2009/05/28)
Addition cyclization of 1,2,3,4-tetrasubstituted 1,4-dilithio-1,3-dienes (Type I) with four equivalents of various aromatic nitriles in the presence of hexamethylphosphoramide (HMPA) gives exclusively fully substituted pyridines in moderate to good yields. Similarly, trisubstituted pyridines can be prepared by the reaction of 2,3-dialkyl- or diaryl-substituted 1,4dilithio-1,3-dienes (Type II) with nitriles. However, five- or six-memberedring fused 2,3-disubstituted 1,4-dilithio1,3-dienes (Type III) reacted with various aromatic and aliphatic nitriles without a-hydrogen atoms to afford tricyclic Δ1- bipyrrolines in high yields. The reaction of six-membered-ring fused 2,3-disubstituted 1,4-dilithio-1,3-diene (Type III) with 2-cyanopyridine afforded the corresponding pyridine, and no tricyclic Δ1- bipyrroline was observed. Seven-membered-ring fused dilithiodienes reacted with PhCN or trimethylacetonitrile to afford the corresponding pyridines in good yield. When 1,2,3,4-tetrasubstituted dilithio reagents (Type I) were treated with Me3SiCN, a tandem silylation/intramolecular substitution process readily occurred to yield siloles, whereas the reaction of 2,3-disubstituted dilithio reagents (Types II and III) with Me3SiCN gave rise to (Z,Z)-dienylsilanes with high stereoselectivity. These results revealed that the formation of tricyclic Δ1-bipyrrolines, pyridines, siloles, and (Z,Z)-dienylsilanes are strongly dependent on the substitution patterns of the dilithio butadienes and the nature of the nitriles employed.
