Synthesis of Cyclo-2,2':4',4":2",2"':4"',4"":2"",2""':4""',4-sexipyridine.
Synthesis of Cyclo-2,2':4',4":2",2"':4"',4"":2"",2""':4""',4-sexipyridine.
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Cyclo-2,2:4,4":2",2":4",4"":2"",2"":4"",4-sexipyridine 的合成。
DOI：
10.1021/jo962236k
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发表时间：
1997
影响因子：
3.6
通讯作者：
R. Mears
中科院分区：
文献类型：
--
作者：
T. Kelly;Yean;R. Mears
描述了通过使用Stille偶联和Kröhnke吡啶合成制备标题化合物（2）。通过应用Stille偶联反应，实现了四吡啶和喹吡啶26、27和28的制备和功能化。将喹并吡啶27酯化为带有被保护的烯醛的吡啶鎓盐30，使得能够通过一锅脱保护/Kröhnke反应由4，4’-联吡啶以九个步骤合成2。使用Kröhnke吡啶合成已被应用于制备二溴化六吡啶19，但尝试通过金属介导的（Pd/Ni/Cu）芳基-芳基偶联程序诱导大环化被证明是不成功的。通过sp-sp（2）或sp-sp偶联方案证明了结合2，2 '-联吡啶单元的乙炔桥连的六吡啶3a和3b是不可接近的。
Preparation of the title compound (2) by use of Stille couplings and a Kröhnke pyridine synthesis is described. By application of the Stille coupling reaction, preparation and functionalization of quater- and quinquepyridines 26, 27, and 28 were achieved. Elaboration of quinquepyridine 27 to the pyridinium salt 30 bearing a protected enal allowed for the synthesis of 2 by a one-pot deprotection/Kröhnke reaction in nine steps from 4,4'-bipyridine. Use of the Kröhnke pyridine synthesis has been applied to prepare sexipyridine dibromide 19, but attempts to induce a macrocyclization via metal-mediated (Pd/Ni/Cu) aryl-aryl coupling procedures proved unsuccessful. Acetylene-bridged sexipyridines 3a and 3b incorporating 2,2'-bipyridine units proved to be inaccessible via sp-sp(2) or sp-sp coupling protocols.