Efficient 1-Hexene Trimerization with Triazacyclohexane Chromium Catalysts and Detailed Product Analysis by <sup>13</sup>C NMR
作者:Alexander G. N. Coxon、Randolf D. Köhn
DOI:10.1021/acscatal.6b00542
日期:2016.5.6
1-hexene, and 1-octene with unprecedented activity, reaching nearly 5000 turnovers in 1 h. The isomer distribution of the trimers has been analyzed in detail by application of quantitative 13C NMR spectroscopy to 13C labeled samples. All endocyclic elimination products predicted by the metallacyclic mechanism have been characterized, and many have been confirmed by their independent syntheses. Significant
描述了三氮杂环己烷铬预催化剂,该催化剂以前所未有的活性催化1-戊烯,1-己烯和1-辛烯的选择性三聚,在1小时内达到了近5000次营业额。三聚体的异构体分布已通过将13 C NMR定量光谱应用于13C标记的样品。已经表征了通过金属环机理预测的所有环内消除产物,并且许多产物已经通过其独立的合成得到了证实。在配体体积变化时观察到异构体分布的显着变化。定量分析对金属环中间体的相对丰度给出了可观的见解,其中1,3-取代的色环戊烷是迄今为止最丰富的静止状态。环的扩展选择性有利于1,2-插入受阻较少的Cr-C键,但是也发现了一些2,1-插入的产物。