Quality Control of 3-CyanopyridineIn 2021, Wang, Chang-Sheng;Sun, Qiao;Garcia, Felipe;Wang, Chen;Yoshikai, Naohiko published 《Cobalt-catalyzed intermolecular [2 + 2 + 2] cycloaddition of nitriles and alkynes: facile synthesis of polyarylpyridines and their mechanochemical cyclodehydrogenation to nitrogen-containing polyaromatics》. 《Angewandte Chemie, International Edition》published the findings. The article contains the following contents:
The transition-metal-catalyzed [2+2+2] cycloaddition of nitriles and alkynes is an established synthetic approach to pyridines; however, these cycloadditions often rely on the use of tethered diynes or cyanoalkynes as one of the reactants. Thus, examples of efficient, fully intermol. catalytic [2+2+2] pyridine synthesis, especially those employing unactivated nitriles and internal alkynes leading to pentasubstituted pyridines, remain scarce. Herein, we report on simple and inexpensive catalytic systems based on cobalt(II) iodide, 1,3-bis(diphenylphosphino)propane, and Zn that promote [2+2+2] cycloaddition of various nitriles and diarylacetylenes for the synthesis of a broad range of polyarylated pyridines. DFT studies support a reaction pathway involving oxidative coupling of two alkynes, insertion of the nitrile into a cobaltacyclopentadiene, and C-N reductive elimination. The resulting tetra- and pentaarylpyridines serve as precursors to hitherto unprecedented nitrogen-containing polycyclic aromatic hydrocarbons via mechanochem. assisted multifold reductive cyclodehydrogenation. Transition metal-catalyzed [2 + 2 + 2] cycloaddition of nitriles and alkynes has been extensively developed as a straightforward and atom-economical synthetic approach to pyridines over the last several decades using various transition metal catalysts, both precious and non-precious. Despite this long history, cycloadditions of this type have often relied on the use of tethered diyne or cyanoalkyne as one of the reactants. Thus, examples of efficient, fully intermol. catalytic [2 + 2 + 2] pyridine synthesis, especially those employing unactivated nitriles and internal alkynes leading to pentasubstituted pyridines, remain scarce. Herein, we report on simple and inexpensive catalytic systems based on cobalt(II) iodide, 1,3-bis(diphenylphosphino)propane, and Zn that promote [2 + 2 + 2] cycloaddition of various nitriles and diarylacetylenes without using a large excess of the nitrile. The present systems allow for the synthesis of broad range of polyarylated pyridines, many of which have not been previously accessed by the [2 + 2 + 2] manifold. Computational studies have supported a reaction pathway involving oxidative coupling of two alkynes, insertion of the nitrile into cobaltacyclopentadiene, and C-N reductive elimination, while shedding light on stepwise nature of the oxidative coupling and insertion processes. We also demonstrate that tetra- and pentaarylpyridines can serve as precursors to hitherto unprecedented nitrogen-containing polycyclic aromatic hydrocarbons via mechanochem. assisted multifold reductive cyclodehydrogenation. And 3-Cyanopyridine (cas: 100-54-9) was used in the research process.
3-Cyanopyridine(cas: 100-54-9) has been shown to have a number of pharmacological effects: it inhibits the production of prostaglandin E2 and nitric oxide in congestive heart failure patients; it prevents the formation of diazonium salt from benzene and nitrogen dioxide; it inhibits the growth of tumor cell lines; and it protects mice from radiation injury by scavenging reactive oxygen species. Quality Control of 3-Cyanopyridine