Palladium-catalyzed dehydrogenation of dihydro-heterocycles using isoprene as the hydrogen acceptor without oxidants
作者:Xiao-Jun Liu、Wen-Peng Wang、Cong-De Huo、Xi-Cun Wang、Zheng-Jun Quan
DOI:10.1039/c6cy02038k
日期:——
efficient and general method for Pd-catalyzed dehydrogenative aromatization of dihydro-heteroatom compounds without external O2 and H2 is first described. The protocol firstly uses isoprene as a hydrogenacceptor. Various dihydro-heterocycles including dihydropyrimidinones, dihydropyrimidines and dihydropyridines can be dehydrogenated to produce the corresponding aromatic heterocyclic compounds.
An oxidation system to synthesize pyridine derivatives has been developed by oxidation of 1,4-dihydropyridines and polyhydroquinoline derivatives in good yields.
已开发出一种氧化系统,通过氧化1,4-二氢吡啶和多羟基喹啉衍生物,可以高产率合成吡啶衍生物。
One-Pot Synthesis and Aromatization of 1,4-Dihydropyridines in Refluxing Water
作者:Guan-Wu Wang、Jing-Jing Xia
DOI:10.1055/s-2005-870022
日期:——
A series of 1,4-dihydropyridines were synthesized in an environmentally benign method, by reacting aldehydes with acetoacetate esters or acetylacetone and ammonium acetate in refluxing water. The thus formed 1,4-dihydropyridines was subsequently oxidized in one-pot to the corresponding pyridine derivatives by either ferric chloride or potassium permanganate.
Triton-X-100 catalyzed synthesis of 1,4-dihydropyridines and their aromatization to pyridines and a new one pot synthesis of pyridines using visible light in aqueous media
作者:Partha Pratim Ghosh、Prasun Mukherjee、Asish R. Das
DOI:10.1039/c3ra40706c
日期:——
temperature. A greener method to synthesize pyridine derivatives has also been developed by the oxidation of 1,4-dihydropyridine derivatives with almost 100% yields and also in a one pot synthesis, employing an aldehyde, ethyl acetoacetate and ammonium acetate in an aqueous micellar medium by irradiation with potassium persulphate in the presence of visiblelight. The one pot protocol offered excellent
CAN Mediated Mechanochemical Synthesis of Substituted Pyridine Derivatives
作者:Radhika Khanna、Aarti Dalal、Kulbir Kadyan、Ramesh Kumar、Parvin Kumar、Ramesh C. Kamboj
DOI:10.2174/1570178615666180102153707
日期:2018.7.2
A simple, green and cost-effective protocol has been devised for the synthesis of
4-substituted-2,6-dimethyl-3,5-pyridinecarboxylates from Hantzsch-type 1,4-dihydropyridines via
rapid oxidation in excellent yields using 1.5 equivalent of ceric ammonium nitrate within 15 minutes in
solvent-free conditions. The method was able to furnish the products in excellent yields. The products
obtained were characterized by their NMR and melting points data.