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[摘要]：Conjugated dienediynes and enediynes with definite geometry have been prepared in a one-pot manner. This protocol involves two types of coupling reaction, a Suzuki-type coupling and either a Hay coupling or a Cadiot-Chodkiewicz coupling. Thus, the copper-mediated cross-coupling reaction of (E)-alk-1-enyldisiamylborane with (trimethylsilyl) ethynyl bromide is carried out in the presence of 1 M NaOMe to generate (E)-alk-3-en-1-yne, which is subjected to either palladium/copper-catalyzed homocoupling in the presence of DABCO or copper-catalyzed heterocoupling with 1-iodoalk-1-yne in the presence of TBD or pyrrolidine in a single reaction pot without isolating (E)-alk-3-en-1-yne. The homocoupling has realized the stereoselective construction of (1E,7E)-alka-1,7-diene-3,5-diynes, and the heterocoupling has achieved the formation of (E)-alk-1-ene-3,5-diynes. In addition, starting from (Z)-alk-1-enyldisiamylborane instead of the E-isomer, this series of reactions has led to the formation of (1Z,7Z)-alka-1,7-diene-3,5-diynes and (Z)-alk-1-ene-3,5-diynes, albeit limiting the scope of the substrate. |
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