进行了铜盐催化的芳香族化合物与元素硫属元素的反应,并以分子氧作为氧化剂。在CuTC(铜(I)噻吩羧酸盐)存在下,3-取代的咪唑并[1,5- a ]吡啶与元素硫的反应以良好的定量收率得到了相应的双咪唑并吡啶基硫化物。即使在有氧氧化条件下,反应也进行。极性溶剂的使用对于反应至关重要,尤其是DMSO(二甲基亚砜)会促进反应。该反应可应用于常见的芳族化合物,例如N-甲基吲哚和二烷基苯胺。吲哚的反应在亲核的C3位置进行,而不是在酸性的C2位置进行。另外,二烷基苯胺的反应以邻位,对位进行。咪唑并吡啶与元素硒在相似条件下的反应得到相应的双咪唑并吡啶二硒化物和双咪唑并吡啶单硒化物。在相同条件下,未反应的咪唑并吡啶易于将得到的二硒化物转化为相应的单硒化物。该反应可用于双官能双咪唑并吡啶和元素硫的共聚,以定量收率得到低聚物。
Synthesis of 2-Azaindolizines by Using an Iodine-Mediated Oxidative Desulfurization Promoted Cyclization of N-2-Pyridylmethyl Thioamides and an Investigation of Their Photophysical Properties
摘要:
Iodine-mediated, oxidative desulfurization promoted cyclization of N-2-pyridylmethyl thioamides serves as an efficient and versatile method for the preparation of 2-azaindolizines (imidazo[1,5-a]pyridines) and rare 2-azaindolizine sulfur-bridged dimers. The 2-azaindolizines prepared in this manner are readily converted to a variety of fluorescent compounds by using transition-metal-catalyzed cross-coupling reactions.
A one-pot synthesis of imidazo[1,5-a]pyridines starting from a carboxylic acid and 2-methylaminopyridines allowing introduction of various substituents at the 1- and 3-positions is achieved using propane phosphoric acid anhydride in ethyl or n-butyl acetate at reflux.
使用丙烷磷酸酐在乙基或正丁基中的一锅合成方法,是从羧酸和2-甲基氨基吡啶开始的咪唑并[1,5- a ]吡啶和2-甲基氨基吡啶,这些取代基允许在1-和3-位引入各种取代基。回流乙酸盐。
1-Alkynyl- and 1-Alkenyl-3-arylimidazo[1,5-<i>a</i>]pyridines: Synthesis, Photophysical Properties, and Observation of a Linear Correlation between the Fluorescent Wavelength and Hammett Substituent Constants
5-a]pyridines showed a good fit to the values predicted by TDDFT calculations at the B3LYP/6-311++G(d,p) level. In addition, the alkynylated imidazo[1,5-a]pyridines obtained showed linearcorrelations between the Hammett substituent constants of the substituents on the arylalkynyl group and their fluorescence wavelengths.
合成了1-炔基和1-烯基-3-芳基咪唑并[1,5- a ]吡啶。80°C下三乙胺中的3-芳基-1-碘咪唑并[1,5- a ]吡啶和各种末端炔与Pd(PPh 3)2 Cl 2(10 mol%)和CuI(10 mol%)的Sonogashira偶联持续12小时,以良好至优异的产率得到相应的1-烯基-3-芳基咪唑并[1,5- a ]吡啶。3-芳基-1-碘咪唑并[1,5- a ]吡啶与各种苯乙烯衍生物的Mizoroki-Heck反应在Pd(OAc)2(5 mol%),IMes·HCl(10 mol%)和Cs下顺利进行2一氧化碳3(2当量)在DMA中于130°C放置20 h,以中等至高收率得到烯基化的咪唑并[1,5- a ]吡啶。所述炔基化产物的荧光最大值和荧光量子产率分别为458-560纳米和Φ ˚F = 0.08-0.26的氯仿溶液中,并且那些链烯基的咪唑并吡啶的是479-537纳米,Φ ˚F =
A novel approach for the synthesis of imidazo and triazolopyridines from dithioesters
作者:Ajjahalli B. Ramesha、Nagarakere C. Sandhya、Chottanahalli S. Pavan Kumar、Mahanthawamy Hiremath、Kempegowda Mantelingu、Kanchugarakoppal S. Rangappa
DOI:10.1039/c6nj01038e
日期:——
Various imidazo- and triazolo-pyridines were synthesised by the intramolecular cyclization of pyridine 2-methylamine and dithioesters under mild conditions.
通过在温和条件下进行吡啶-2-甲胺和二硫酯的分子内环化,合成了各种咪唑和三唑吡啶。
Tandem approach for the synthesis of 3-sulfenylimidazo[1,5-a]pyridines from dithioesters
作者:Ajjahalli. B. Ramesha、Chottanahalli. S. Pavan Kumar、Nagarakere. C. Sandhya、Manikyanahalli. N. Kumara、Kempegowda Mantelingu、Kanchugarakoppal. S. Rangappa
DOI:10.1039/c6ra03771b
日期:——
Iodine-mediated synthesis of 3-sulfenylimidazo[1,5-a]pyridines via C–H functionalization has been achieved using dithioesters, 2-methylaminopyridines and sulfonyl hydrazides. A library of 3-sulfanylimidazopyridines and imidazopyridines with broad functionalities are synthesized under metal-free reaction conditions.
使用二硫酯,2-甲基氨基吡啶和磺酰肼,可以实现碘经C–H官能团介导的3-亚磺酰基咪唑并[1,5- a ]吡啶的合成。在无金属的反应条件下,合成了具有广泛功能的3-磺酰胺基咪唑并吡啶和咪唑并吡啶的文库。
Palladium-catalyzed Highly Regioselective C-3 Arylation of Imidazo[1,5-<i>a</i>]pyridine
A direct palladium-catalyzedhighly regioselective C-3 arylation of imidazo[1,5-a]pyridine with aryl bromides has been developed. This reaction is quite general with respect to the aryl or hetaryl bromide.