Novel electron-rich bulky phosphine ligands facilitate the palladium-catalyzed preparation of diaryl ethers
Novel electron-rich bulky phosphine ligands facilitate the palladium-catalyzed preparation of diaryl ethers
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DOI：
10.1021/ja990324r
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发表时间：
1999-05-12
影响因子：
15
通讯作者：
Buchwald, SL
中科院分区：
文献类型：
--
作者：
Aranyos, A;Old, DW;Buchwald, SL
描述了钯催化形成二芳基醚的一般方法。富电子的、大体积的芳基二烷基膦配体（其中两个烷基是叔丁基或1-金刚烷基）是转化成功的关键。在100 ℃的甲苯中，使用氢化钠或磷酸钾作为碱，可以将各种缺电子、电中性和富电子的芳基溴化物、氯化物和三氟甲磺酸酯与各种酚化合。膦配体的大体积但碱性的性质被认为是增加二芳基醚从钯还原消除的速率的原因。
A general method for the palladium-catalyzed formation of diaryl ethers is described. Electron-rich, bulky aryldialkylphosphine ligands, in which the two alkyl groups are either tert-butyl or 1-adamantyl, are the key to the success of the transformation. A wide range of electron-deficient, electronically neutral and electron-rich aryl bromides, chlorides, and triflates can be combined with a variety of phenols with the use of sodium hydride or potassium phosphate as base in toluene at 100 degrees C. The bulky yet basic nature of the phosphine ligand is thought to be responsible for increasing the rate of reductive elimination of the diaryl ether from palladium.