Zhou Tao, Zuo Jing, Xie Haojie, Zhao Xing, Zhao Mei-Xin, Zhang Jun
Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.
Dalton Trans. 2024 Aug 20;53(33):14011-14017. doi: 10.1039/d4dt01521e.
A series of novel diphosphinoamine (PNP) ligands bearing a -alkenyl group were synthesized and applied in chromium-catalyzed selective ethylene tri-/tetramerization by combination of Cr(acac) and modified methylalumoxane (MMAO-3A). The ligand substitution and oligomerization conditions have a remarkable influence on the catalytic activity and controllable selectivity. Most of these PNP ligands are highly active for ethylene tri-/tetramerization with considerable selectivity. An asymmetric diisopropenylphosphanyl ligand with an -cyclohexyl group achieved the highest activity of 2036 kg (g Cr h) with a high total selectivity of 81.1 wt% toward valuable 1-hexene (43.0 wt%) and 1-octene (38.1 wt%) at 40 bar ethylene and 60 °C. An asymmetric mixed isopropenyl/ethylphosphanyl ligand with an -isopropyl group exhibited a high 1-octene selectivity of 65.5 wt% and a high total 1-hexene/1-octene selectivity (91.5 wt%) with a high activity of 1256 kg (g Cr h).
合成了一系列带有α-烯基的新型二膦基胺（PNP）配体，并通过将Cr(acac)与改性甲基铝氧烷（MMAO-3A）结合，将其应用于铬催化的乙烯选择性三聚/四聚反应中。配体取代和齐聚条件对催化活性和可控选择性有显著影响。这些PNP配体中的大多数对乙烯三聚/四聚反应具有高活性和相当高的选择性。一种带有α-环己基的不对称二异丙烯基膦基配体在40 bar乙烯和60°C条件下实现了最高活性2036 kg/(g Cr h)，对有价值的1-己烯（43.0 wt%）和1-辛烯（38.1 wt%）的总选择性高达81.1 wt%。一种带有α-异丙基的不对称混合异丙烯基/乙基膦基配体表现出65.5 wt%的高1-辛烯选择性和91.5 wt%的高1-己烯/1-辛烯总选择性，活性为1256 kg/(g Cr h)。
