Ammonium iodide-promoted cyclization of ketones with DMSO and ammonium acetate for synthesis of substituted pyridines
作者:Xiaojun Pan、Qiao Liu、Liming Chang、Gaoqing Yuan
DOI:10.1039/c5ra07584j
日期:——
A simple and efficient method has been developed for the synthesis of symmetrical and unsymmetrical pyridines via NH4I-promoted cyclization of ketones with DMSO and NH4OAc. It was found that methyl ketones always gave selective formation of the unsymmetrical pyridine, while non-methyl ketones gave unpredictable results (symmetrical or non-symmetrical product only, or a mixture of the two). In addition
has been developed for the preparation of substituted pyridines from ketones. In this transformation, the co‐product formic acid was formed from ammonium formate, which acted as an important catalyst for the reaction. Notably, this transformation exhibited a broad substrate scope towards a wide variety of different ketones to give the corresponding substituted pyridines in high yields. Mechanistic
Triarylbismuthanes as Threefold Aryl-Transfer Reagents in Regioselective Cross-Coupling Reactions with Bromopyridines and Quinolines
作者:Maddali L. N. Rao、Ritesh J. Dhanorkar
DOI:10.1002/ejoc.201402455
日期:2014.8
Cross-coupling studies using bromopyridines and bromoquinolines with triarylbismuths as threefold coupling reagents in substoichiometric amounts under Pd-catalysed conditions are disclosed. The reactivity was high with both mono- and dibromopyridyl substrates, and mono- and bis-couplings were carried out regioselectively. A library of monoaryl and diaryl pyridines was formed in high yields. A one-pot
Pd-Catalyzed Decarboxylation and Dual C(sp<sup>3</sup>)–H Functionalization Protocols for the Synthesis of 2,4-Diarylpyridines
作者:Raghuram Gujjarappa、Nagaraju Vodnala、Mohan Kumar、Chandi C. Malakar
DOI:10.1021/acs.joc.8b02971
日期:2019.5.3
The Pd-catalyzed decarboxylation and dualC(sp3)–Hbondfunctionalization approaches have been described for the preparation of symmetrical and unsymmetrical 2,4-diarylpyridines. The developed transformations were realized using nonactivated aromatic ketones and amino acids as C–N sources. The efficacy of the catalyst and reagent combination drives the transformation toward the formation of desired