Electronic Effect Rate Enhancement in the Stereoselective Living Coordinative Polymerization of α-Olefins by α,α,α-Trifluoroacetamidinate-Modified Group 4 Metal CPAM<sup>CF3</sup> Initiators
作者:Rick R. Thompson、Peter Y. Zavalij、Lawrence R. Sita
DOI:10.1021/acs.organomet.8b00839
日期:2019.1.28
The C1-symmetric cyclopentadienyl, α,α,α-trifluoroacetamidinate (CPAMCF3) group 4 metal dimethyl complexes, Cp*[N(Et)C(CF3)N(tBu)]M(Me)2 (Cp* = η5-C5Me5) for M = Zr (3) and Hf (4), serve as initiators for the stereoselective (isotactic) living coordination polymerization (LCP) of α-olefins upon in situ “activation” using one equiv of the borate co-initiator, [PhNMe2H][B(C6F5)4]. For the LCP of 1-hexene
所述Ç 1 -对称环戊二烯基,α,α,α-trifluoroacetamidinate(CPAM CF3)4个族金属配合物二甲酯中,Cp * [N(ET)C(CF 3)N(吨丁基)] M(Me)的2(CP * =η 5 -C 5我5)为M = Zr的(3)和HF(4),充当用于立体选择性引发剂(全同立构使用一个当量)在原位“激活”活α烯烃的配位聚合(LCP)硼酸盐共引发剂[PhNMe 2 H] [B(C 6 F 5)4 ]的组成。对于1-己烯的LCP,使用4在聚合中,速率的6倍的增强- [R p,相对于该相同的α烯烃时,非氟化CPAM的LCP观察到CH3结构类似物中,Cp * [N(ET)C(CH 3)N(吨Bu)Hf(Me)2 ](2)用作预引发剂。对于丙烯的LCP,在8倍- [R p使用CPAM CF3 preinitiator 4现在允许生产的反应条件下是高度立体和区域规整的等规聚丙