Room Temperature Metal-Catalyzed Oxidative Acylation of Electron-Deficient Heteroarenes with Alkynes, Its Mechanism, and Application Studies
作者:Shweta Sharma、Mukesh Kumar、Ram A. Vishwakarma、Mahendra K. Verma、Parvinder Pal Singh
DOI:10.1021/acs.joc.8b01475
日期:2018.10.19
room-temperature, regioselective Minisci reaction for the acylation of electron-deficient heteroarenes with alkynes. The method has broad functional group compatibility and gives exclusively monoacylated products in good to excellent yields. The mechanistic pathway was analyzed based on a series of experiments confirming the involvement of a radical pathway. The 18O-labeling experiment suggested that water
A facile synthetic route for 2-pyridyl derivatives: direct preparation of a stable 2-pyridylzinc bromide and its copper-free and pd-catalyzed coupling reactions
作者:Seung-Hoi Kim、Reuben D. Rieke
DOI:10.1016/j.tetlet.2009.07.004
日期:2009.9
Direct preparation of 2-pyridylzinc bromide has been developed. Interestingly, the subsequent coupling reactions with acid chlorides have been carried out without any transition metal catalyst. 2-Pyridylaryl compounds, symmetrical and unsymmetrical 2,2′-bipyridines were also successfully obtained from palladium-catalyzed coupling reactions of 2-pyridylzinc bromide under mild conditions.
2-Pyridyl and 3-pyridylzinc bromides: direct preparation and coupling reaction
作者:Seung-Hoi Kim、Reuben D. Rieke
DOI:10.1016/j.tet.2010.02.061
日期:2010.4
A facile synthetic approach to the direct preparation of 2-pyridyl and 3-pyridylzinc bromides has been demonstrated usingRieke zinc with 2-bromopyridine and 3-bromopyridine, respectively. A variety of different electrophiles have been coupled with the resulting organozinc reagents to give the corresponding cross-coupling products in moderate to good yields.
Ketone Synthesis under Neutral Conditions. Cu(I) Diphenylphosphinate-Mediated, Palladium-Catalyzed Coupling of Thiol Esters and Organostannanes
作者:Rüdiger Wittenberg、Jiri Srogl、Masahiro Egi、Lanny S. Liebeskind
DOI:10.1021/ol034962x
日期:2003.8.1
[reaction: see text] A versatile approach to ketone synthesis is described. The reaction relies on the palladium-catalyzed, copper diphenylphosphinate-mediated coupling of thiol esters with organostannanes under neutral reaction conditions. This reaction complements the previously described coupling of thiol esters with boronic acids that used dual thiophilic-borophilic activation methodology.
allowed us to rationalize both the thermal and photochemical reaction mechanisms of the designed hydrazones. Whereas introducing an electron-withdrawing pyridyl moiety in benzoylpyridine hydrazones leads to thermal stabilities exceeding 200 years, extended π-conjugation in naphthoylquinoline hydrazones pushes the absorption maxima toward the visible spectral region. In either case, the compounds retain
具有数百年亚稳态热稳定性的 P 型光开关的设计可以使用 350 nm 以上的激发波长进行有效转换,这仍然是光致变色领域的一个挑战。在这方面,我们设计并合成了一组扩展的 13 种吡啶/喹啉腙,并系统地研究了结构-性质关系,定义了它们的动力学和光开关参数。我们表明,吡啶腙结构基序的工作波长可以有效地向可见光区域转移,而不会同时丧失其高热稳定性。此外,我们用量子化学计算和超快瞬态吸收光谱表征了基态和激发态势能表面,这使我们能够合理化设计腙的热和光化学反应机制。虽然在苯甲酰基吡啶腙中引入吸电子吡啶基部分导致热稳定性超过 200 年,但萘酰基喹啉腙中的扩展 π 共轭将吸收最大值推向可见光谱区域。在任何一种情况下,这些化合物都保留了高效的光开关特性。我们的研究结果为合理设计新型基于腙的 P 型光开关系列开辟了道路,在光子学或光药理学中具有很高的应用潜力。萘酰喹啉腙中的扩展 π 共轭将吸收最大值推向可见