受阻路易斯对与共轭二炔的加成反应：两性离子 1,2,3-丁三烯衍生物的形成。
Frustrated Lewis pair addition to conjugated diynes: formation of zwitterionic 1,2,3-butatriene derivatives.
机构信息
Organisch-Chemisches Institut der Westfälischen Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany.
出版信息
Dalton Trans. 2012 Aug 14;41(30):9135-42. doi: 10.1039/c2dt30321c. Epub 2012 May 31.
The frustrated Lewis pair B(C(6)F(5))(3)/P(o-tolyl)(3) (4a) reacts with 4,6-decadiyne to give the trans-1,2-addition product 5. In contrast, the B(C(6)F(5))(3)/P(t)Bu(3) FLP (4b) reacts with this substrate to give the trans-1,4-adduct trans-6. The cumulene trans-6 undergoes trans-/cis-isomerization upon photolysis to give a ca. 1:1 trans-6/cis-6 mixture. The FLP 4b reacts with 2,6-hexadiyne at r.t. to yield a ca. 4:1 mixture of their trans-1,2- and trans-1,4-addition products (7,8). DFT calculations showed that the zwitterionic 1,4-addition products are favored under thermodynamic control. Thermolysis of the kinetic trans-1,2-addition product (7) (80 °C, bromobenzene) does not lead to the thermodynamically favored 1,4-isomer (8), but instead elimination of isobutylene occurs to the formal trans-1,2-adduct (9) of the B(C(6)F(5))(3)/PH(t)Bu(2) pair. Compounds 5, 6, 7, 8, 9 were analyzed by X-ray diffraction.
受阻路易斯对 B(C(6)F(5))(3)/P(o-tolyl)(3) (4a) 与 4,6-癸二炔反应，生成顺式-1,2-加成产物 5。相比之下，B(C(6)F(5))(3)/P(t)Bu(3) FLP (4b) 与该底物反应，生成顺式-1,4-加合物顺式-6。累积二烯顺式-6 在光解下发生顺/反异构化，得到约 1:1 的顺式-6/反式-6 混合物。FLP 4b 在室温下与 2,6-己二炔反应，得到其顺式-1,2-和顺式-1,4-加成产物（7,8）的约 4:1 混合物。DFT 计算表明，在热力学控制下，两性离子 1,4-加成产物是有利的。动力学顺式-1,2-加成产物（7）（80°C，溴苯）的热解不会导致热力学上有利的 1,4-异构体（8），而是发生异丁烯消除，生成 B(C(6)F(5))(3)/PH(t)Bu(2) 对的形式顺式-1,2-加成产物（9）。化合物 5、6、7、8、9 通过 X 射线衍射进行了分析。
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