Lewis Acid Catalyzed trans-Allylsilylation of Unactivated Alkynes
Lewis Acid Catalyzed trans-Allylsilylation of Unactivated Alkynes
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路易斯酸催化未活化炔烃的反式烯丙基甲硅烷基化
DOI：
10.1021/ja970443b
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发表时间：
1997
影响因子：
15
通讯作者：
Yoshinori Yamamoto
中科院分区：
文献类型：
--
作者：
Eiji Yoshikawa;V. Gevorgyan;N. Asao;Yoshinori Yamamoto
在催化量的HfCl 4或EtAlCl 2-TMSCl催化剂体系存在下，将不同取代的烯丙基硅烷2加成到未活化的炔1上，以高产率区域和立体选择性地产生甲硅烷基化的1，4-二烯3。通过用1H NMR和毛细管GLC方法分析粗反应混合物证实了排他性的反式加成方式。各种烯丙基硅烷2a-e在HfCl 4存在下与苯乙炔（1a）反应的相对反应性与2a-e与碳正离子的相对反应速率的良好一致性支持阳离子物种11作为反应中间体的参与。提出了HfCl 4和EtAlCl 2 −TMS催化炔的反式烯丙基硅烷化反应的机理。
The addition of different substituted allylsilanes 2 to unactivated alkynes 1 in the presence of catalytic amounts of HfCl4 or the EtAlCl2−TMSCl catalyst system produced in high yields the silylated 1,4-dienes 3 regio- and stereoselectively. The exclusive trans manner of addition was confirmed by analysis of crude reaction mixtures by 1H NMR and capillary GLC methods. Good agreement of relative reactivities of reaction of various allylsilanes 2a−e toward phenylacetylene (1a) in the presence of HfCl4 with the relative reaction rates of 2a−e with carbenium ions supported the involvement of cationic species 11 as a reaction intermediate. The mechanisms for the HfCl4 and EtAlCl2−TMS catalyzed trans-allylsilylation of alkynes are proposed.