Homo- and Heterocoupling of Terminal Conjugated Enynes: One-Pot Synthesis of Alka-1,7-diene-3,5-diynes and Alk-1-ene-3,5-diynes via Two Types of Coupling Reaction
作者:Masayuki Hoshi、Mitsuhiro Okimoto、Shingo Nakamura、Shinya Takahashi
DOI:10.1055/s-0030-1260253
日期:2011.12
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.
已制备具有确定几何构型的共轭二烯二炔和烯二炔,采用一种一步法。这一方法涉及两种类型的偶联反应,即铃木偶联(Suzuki-type coupling)和海偶联(Hay coupling)或卡迪奥-乔德基维奇偶联(Cadiot-Chodkiewicz coupling)。因此,(E)-烯-1-烯基二异戊基硼酸((E)-alk-1-enyldisiamylborane)与(烷基三甲基硅基)乙炔溴化物((trimethylsilyl)ethynyl bromide)的铜介导交叉偶联反应在1 M NaOMe的存在下进行,从而生成(E)-烷-3-烯-1-炔((E)-alk-3-en-1-yne),然后在单一反应瓶中在DABCO的存在下进行钯/铜催化的自偶联反应,或在TBD或吡咯烷的存在下进行铜催化的异偶联反应,而不需要分离(E)-烷-3-烯-1-炔。自偶联反应实现了(1E,7E)-烷-1,7-二烯-3,5-二炔的立体选择性合成,而异偶联反应则形成了(E)-烷-1-烯-3,5-二炔。此外,若以(Z)-烯-1-烯基二异戊基硼酸((Z)-alk-1-enyldisiamylborane)替代E异构体,这系列反应也能形成(1Z,7Z)-烷-1,7-二烯-3,5-二炔和(Z)-烷-1-烯-3,5-二炔,尽管底物的范围受限。