Alkene Transfer Hydrogenation with Alkaline-Earth Metal Catalysts
Alkene Transfer Hydrogenation with Alkaline-Earth Metal Catalysts
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DOI：
10.1002/anie.201813910
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发表时间：
2019-03-22
影响因子：
16.6
通讯作者：
Harder, Sjoerd
中科院分区：
文献类型：
--
作者：
Bauer, Heiko;Thum, Katharina;Harder, Sjoerd
利用简单的AeN(2)催化剂[Ae=Ca, Sr, Ba; N=N(SiMe3)(2)]，使用1,4-环己二烯(1,4-CHD)作为H源。 1,4-CHD 与 AeN(2) 反应生成苯、NH 和金属氢化物 NAeH（或其聚集体），后者是烯烃加氢的催化剂。 BaN2 是迄今为止最活跃的催化剂。活化的 C=C 键（例如苯乙烯）的氢化在室温下进行，没有聚合物形成。未活化（孤立的）C=C 键（例如 1-己烯）需要更高的温度（120 摄氏度），但不会发生双键异构化。配体完全控制催化反应的过程，可以是：1）烯烃TH，2）1,4-CHD脱氢，或3）烯烃聚合。 DFT 计算支持通过 1,4-CHD 去质子化随后进行 H 转移来形成金属氢化物物质。方便地获得大量 BaN2、其高活性和选择性以及 TH 的许多优点使其成为一种简单但有吸引力的烯烃加氢过程。
The alkene transfer hydrogenation (TH) of a variety of alkenes has been achieved with simple AeN(2) catalysts [Ae=Ca, Sr, Ba; N=N(SiMe3)(2)] using 1,4-cyclohexadiene (1,4-CHD) as a H source. Reaction of 1,4-CHD with AeN(2) gave benzene, NH, and the metal hydride species NAeH (or aggregates thereof), which is a catalyst for alkene hydrogenation. BaN2 is by far the most active catalyst. Hydrogenation of activated C=C bonds (e.g. styrene) proceeded at room temperature without polymer formation. Unactivated (isolated) C=C bonds (e.g. 1-hexene) needed a higher temperature (120 degrees C) but proceeded without double-bond isomerization. The ligands fully control the course of the catalytic reaction, which can be: 1)alkene TH, 2)1,4-CHD dehydrogenation, or 3)alkene polymerization. DFT calculations support formation of a metal hydride species by deprotonation of 1,4-CHD followed by H transfer. Convenient access to larger quantities of BaN2, its high activity and selectivity, and the many advantages of TH make this a simple but attractive procedure for alkene hydrogenation.