byproduct. Treatment of 2 with EtAlCl2 did not yield an active catalyst. The reaction of CrCl2(THF)2 with [(t-Bu)NP(Ph)2N(t-Bu)]−Li+, containing pentavalent phosphorus, afforded the Cr(II) derivative [(t-Bu)NP(Ph)2N(t-Bu)]Cr(μ-Cl)2Li(THF)2 (4). Its alkylation with EtLi gave the ethyl-bridged dimer [(t-Bu)NP(Ph)2N(t-Bu)]Cr(μ-Et)}2 (5), which, upon thermolysis, afforded [(t-Bu)NP(Ph)2N(t-Bu)]2Cr (6). The structures
比较了两种分别具有三价和五价
磷,基于具有N
PN结构基序的阴离子
配体的催化体系,并比较了它们选择性
乙烯三聚的能力。在三价
磷配体的情况下,Cr(II)催化剂前体[(t -Bu)N
PN(t -Bu)] 2 Cr(1)与2当量的MeLi反应得到Cr(III)物种[[ t -Bu)NP(Me)N(t -Bu )] 2 CrLi(OEt 2)(2)。与3当量的MeLi进行的相同反应产生了Cr(II)物种[(t- Bu)NP(Me)N(t -Bu)] Cr(μ-Me)} 2 Li(THF)}2(3)。2和3的P原子均已被甲基化。用MAO活化2和3产生寡聚物的SF分布。相反,用EtAlCl 2活化3只能得到
1-己烯以及少量副产物。的治疗2与EtAlCl 2没有产生活性催化剂。CrCl 2(THF)2与[(t- Bu)NP(Ph)2 N(t -Bu)] - Li +的反应含有五价
磷,得到Cr(II)衍
生物[(t-