Transition-metal-free selective pyrimidines and pyridines formation from aromatic ketones, aldehydes and ammonium salts
作者:Jinjin Chen、Huanxin Meng、Feng Zhang、Fuhong Xiao、Guo-Jun Deng
DOI:10.1039/c9gc02077b
日期:——
An efficient synthesis of pyrimidines and pyridines has been developed from readily available aromaticketones, aldehydes and ammonium salts under transition-metal-free conditions. In this strategy, ammonium salts were used as nitrogen sources and only water was generated as a nontoxic byproduct. A catalytic amount of NaIO4 played an important role in the selectivity control, whereas substituted pyridines
Direct synthesis of 2,4,5-trisubstituted imidazoles and di/tri-substituted pyrimidines via cycloadditions of α,β-unsaturated ketones/aldehydes and N′-hydroxyl imidamides
作者:Ping Wu、Xueguo Zhang、Baohua Chen
DOI:10.1016/j.tetlet.2019.03.025
日期:2019.4
di/trisubstituted pyrimidines via iron-catalyzed cross-dehydrogenative coupling (CDC), with excellent tolerance and yields, has been developed. In this report, α,β-unsaturatedaldehydes/ketones and N′-hydroxyl imidamides undergo [3+2] and [3+3] cycloadditions in two processes, involving iron-mediated Michael reaction, Robinson Annulation and 1,5-electrocyclization.
Secondary amines immobilized inside magnetic mesoporous materials as a recyclable basic and oxidative heterogeneous nanocatalyst for the synthesis of trisubstituted pyrimidine derivatives
A novel magnetic MCM-41 nanocomposite-based catalyst is reported for the first time in the multicomponent synthesis of trisubstituted pyrimidines in which piperazine is immobilized inside the mesochannels of magnetic MCM-41 as an organic base (α-Fe2O3-MCM-41-piperazine). This nanocatalyst was thoroughly characterized by various techniques such as FT-IR, XRD, SEM, TEM, EDX and N2-adsorption isotherms. Very uniform dispersion and ordered mesopores of α-Fe2O3-MCM-41 causes piperazine molecules to be distributed very finely on the internal surface of the pores, resulting in a very useful and robust magnetically recyclable amine-based heterogeneous nanocatalyst. This catalytic system showed remarkable activity in the solvent-free synthesis of 2,4,6-trisubstituted pyrimidine derivatives.