COUPLING OF ARYL CHLORIDES BY NICKEL AND REDUCING METALS
COUPLING OF ARYL CHLORIDES BY NICKEL AND REDUCING METALS
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DOI：
10.1021/jo00364a002
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发表时间：
1986-07-11
影响因子：
3.6
通讯作者：
KELSEY, DR
中科院分区：
文献类型：
--
作者：
COLON, I;KELSEY, DR
研究了一种由芳酰氯高效合成双芳基（二芳烃）的方法。偶联剂是无水镍盐和三苯基膦在还原性金属（Zn、Mg或Mn）存在下的催化混合物。该反应在温和条件下迅速发生，可耐受多种官能团，采用空气稳定的起始材料，并可在普通实验室玻璃器皿中方便地运行。过量的还原金属驱动偶联过程，甚至允许芳酰氯偶联到高产量，这是比以前使用化学计量零价镍试剂的偶联过程的显著优势。该反应为伪零级萘酰氯，由2,2 '-联吡啶和卤化物盐（F< Cl< Br< I）促进。研究了一些反应变量，并讨论了它们对动力学和产率的影响。三苯基膦的还原和芳基转移是主要的副反应，在大多数情况下可以最小化。提出了一种符合观察到的动力学和反应参数的耦合机制，其中关键步骤是锌将芳基镍还原为芳基镍(I)配合物。
An efficient synthesis of biaryls (diarenes) from aryl chlorides has been developed and investigated. The coupling reagent is a catalytic mixture of anhydrous nickel salt and triphenylphosphine in the presence of a reducing metal (Zn, Mg, or Mn). The reaction occurs rapidly under mild conditions, tolerates a variety of functional groups, employs air-stable starting materials, and can be run conveniently in ordinary laboratory glassware. Excess reducing metal drives the coupling process and allows even aryl chloridesto be coupled to high yields, a distinguishing advantage over previous coupling processes which employed stoichiometric zero-valent nickel reagents. The reaction is pseudo-zero-order inaryl chloride and is promoted by 2, 2'-bipyridine and by halide salts (F< Cl< Br< I). A number of reaction variableshave been examined and their effects on the kinetics and yields are discussed. Reduction and aryl transfer from triphenylphosphine, the major side reactions, can be minimized in most cases. A coupling mechanism consistent with theobserved kinetics and reaction parameters is proposed in which the key step is reduction of an arylnickel species by zinc to an arylnickel (I) complex.