The control of the regioselectivity of metal‐catalyzed α‐olefins polymerization is of everlasting interest. Most nickel and palladium catalysts show high regioselectivity involving 2,1‐insertion of α‐olefins and 1,ω‐enchainment chain‐straightening, especially α‐diimine nickel catalysts. In this contribution, we report extremely rare regioselective chain‐straightening polymerization of α‐olefins through 2,ω‐enchainment using unsymmetrical amine–imine nickel catalysts. The polymerizations of α‐olefins (1‐hexene, 1‐octene, and 1‐decene) were studied in detail, and the effects of catalyst structure, reaction temperature, and monomer concentration on the polymerization activity and the regioselectivity were examined. The unsymmetrical N‐substituents of the amine–imine nickel catalysts play a crucial role in the regioselectivity. High regioselectivity involving 80.4% 1,2‐insertion and 84.5% 2,ω‐enchainment is realized to produce amorphous polyolefins without melting temperatures.

中文翻译：

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使用胺-亚胺镍催化剂通过 2,ω-链进行 α-烯烃的区域选择性链矫直聚合

金属催化α-烯烃聚合的区域选择性的控制一直受到人们的关注。大多数镍和钯催化剂表现出高区域选择性，涉及α-烯烃的2,1-插入和1,ω-链矫直，特别是α-二亚胺镍催化剂。在这篇文章中，我们报道了使用不对称胺-亚胺镍催化剂通过 2,ω-链链进行极其罕见的 α-烯烃区域选择性链拉直聚合。详细研究了α-烯烃（1-己烯、1-辛烯和1-癸烯）的聚合，并考察了催化剂结构、反应温度和单体浓度对聚合活性和区域选择性的影响。不对称的氮胺-亚胺镍催化剂的取代基在区域选择性中起着至关重要的作用。实现了 80.4% 1,2-插入和 84.5% 2,ω-链链的高区域选择性，无需熔融温度即可生产无定形聚烯烃。