One-shot double elimination process: a practical and concise protocol for diaryl acetylenes.
One-shot double elimination process: a practical and concise protocol for diaryl acetylenes.
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DOI：
10.1002/asia.200600073
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发表时间：
2006-09
期刊：
影响因子：
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通讯作者：
A. Orita;Hisataka Taniguchi;J. Otera*
中科院分区：
文献类型：
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作者：
A. Orita;Hisataka Taniguchi;J. Otera*
在芳甲基砜、芳醛和氯代磷酸二乙酯的THF溶液中加入六甲基二硅基氨基锂，可以得到多种二芳基乙炔，产率较高。在这种一步法中，连续进行许多转化，如羟醛缩合反应、羟醛酸酯的磷酸化和所得β-取代砜的双消除，以提供所需的乙炔。通过取代苯基上的卤素原子加速了一步反应过程，得到了不对称取代的二芳基乙炔，而不污染脱卤产物。具有其他取代基如CF 3、乙氧羰基、二甲氨基、TMS-乙炔基以及吡啶基和噻吩基部分的二芳基乙炔也可用该方法获得。然而，在相同条件下，以中等产率获得了甲氧基取代的化合物，但当使用二异丙基氨基锂时，产率增加。
A variety of diaryl acetylenes were obtained in good yields when lithium hexamethyldisilazide was added to a solution of arylmethyl sulfone, aryl aldehyde, and chlorodiethylphosphate in THF. In this one-shot process, a number of transformations such as aldol reaction, phosphorylation of aldolate, and double elimination of the resulting beta-substituted sulfone proceeded successively to afford the desired acetylenes. The one-shot process was accelerated by the substitution of halogen atoms on the phenyl groups, and unsymmetrically substituted diaryl acetylenes were obtained without contamination of the dehalogenated products. Diaryl acetylenes with other substituents such as CF3, ethoxycarbonyl, dimethylamino, TMS-acetylene groups, as well as pyridinyl and thienyl moieties were also accessible with this method. However, methoxy-substituted compounds were obtained in moderate yields under the same conditions, but the yields were increased when lithium diisopropylamide was used instead.