22440-29-5Relevant academic research and scientific papers
Cobalt complexes of redox noninnocent azo-aromatic pincers. Isolation, characterization, and application as catalysts for the synthesis of quinazolin-4(3: H)-ones
Das, Siuli,Mandal, Sutanuva,Mondal, Rakesh,Paul, Nanda D.,Sinha, Suman
, p. 8448 - 8459 (2020)
Herein we report the synthesis, characterization and catalytic application of three new cobalt(ii)-complexes of redox noninnocent arylazo ligands, 2-(phenylazo)-1,10-phenanthroline (L1a), 2-(4-chlorophenylazo)-1,10-phenanthroline (L1b) and 2,9-bis(phenyldiazo)-1,10-phenanthroline (L2) respectively. The reaction of L1a with CoIICl2·6H2O produced a μ-dichloro bridged binuclear cobalt(ii)-complex [CoII2(L1a)2Cl2] (1a) while the same reaction when carried out with 2-(4-chlorophenyl)azo-1,10-phenanthroline (L1b) and 2,9-bis(phenyldiazo)-1,10-phenanthroline (L2) ligands produced two new mononuclear five-coordinate cobalt(ii)-complexes 1b and 2 respectively. In complex 1a and 1b, the ligands L1a and L1b are coordinated to the cobalt(ii)-center in a tridentate mode utilizing all of its nitrogen donor sites while in complex 2 one of the azo-donor sites of the ligand L2 remain pendant. All these complexes were characterized using available spectroscopic techniques and DFT studies. We further explored the potential of these complexes as catalysts for the synthesis of pharmaceutically important organic compounds via the functionalization of alcohols. A variety of substituted quinazolin-4(3H)-ones were synthesized under aerobic conditions via the coupling of alcohols and 2-aminobenzamide using 1b as the catalyst. Mechanistic investigations revealed that both cobalt and the arylazo scaffold act synergistically during catalysis. This journal is
Ortho -Naphthoquinone-catalyzed aerobic oxidation of amines to fused pyrimidin-4(3 H)-ones: A convergent synthetic route to bouchardatine and sildenafil
Kim, Hun Young,Kim, Kyeongha,Oh, Kyungsoo
, p. 31101 - 31105 (2020/09/23)
A facile access to fused pyrimidin-4(3H)-one derivatives has been established by using the metal-free ortho-naphthoquinone-catalyzed aerobic cross-coupling reactions of amines. The utilization of two readily available amines allowed a direct coupling strategy to quinazolinone natural product, bouchardatine, as well as sildenafil (Viagra) in a highly convergent manner. This journal is
One-Pot Cascade Synthesis of Quinazolin-4(3H)-ones via Nickel-Catalyzed Dehydrogenative Coupling of o-Aminobenzamides with Alcohols
Parua, Seuli,Das, Siuli,Sikari, Rina,Sinha, Suman,Paul, Nanda D.
, p. 7165 - 7175 (2017/07/26)
In this paper, we report a general, efficient, and environmentally benign method for the one-pot cascade synthesis of quinazolin-4(3H)-ones via acceptorless dehydrogenative coupling of o-aminobenzamide with alcohols catalyzed by a simple Ni(II) catalyst, [Ni(MeTAA)], featuring a tetraaza macrocyclic ligand (tetramethyltetraaza[14]annulene (MeTAA)). A wide variety of substituted quinazolin-4(3H)-ones were synthesized in high yields starting from readily available benzyl alcohols and o-aminobenzamides. Several controlled reactions along with deuterium labeling studies were carried out to establish the acceptorless dehydrogenative nature of the reactions.
