Mechanistic Studies of Ethylene and α-Olefin Co-oligomerization Catalyzed by Chromium-PNP Complexes.
Mechanistic Studies of Ethylene and α-Olefin Co-oligomerization Catalyzed by Chromium-PNP Complexes.
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DOI：
10.1021/om300492r
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发表时间：
2012-07-23
期刊：
影响因子：
2.8
通讯作者：
Bercaw JE
中科院分区：
文献类型：
--
作者：
Do LH;Labinger JA;Bercaw JE
为了探索由乙烯作为化学原料生产窄分布的中长链烃的可能性，研究了乙烯和线性α-烯烃（LAO）的共齐聚，使用先前报道的铬络合物[CrCl 3（PNPOMe）]（1，其中PNPOMe = N，N-双（双（邻甲氧基苯基）膦基）甲胺）。在乙烯和1-己烯的存在下，通过用改性的甲基铝氧烷（MMAO）处理来活化1，主要得到C6和C10烯烃产物。的C10异构体的身份，分配详细的气相色谱和质谱分析，强烈支持的机制，涉及五元和七元metallacyclic中间体，包括乙烯和LAO单位。使用1-庚烯作为机理探针，确定了从乙烯形成1-己烯与乙烯/LAO共三聚体的形成是竞争性的，并且还产生了衍生自一个乙烯和两个LAO分子的共三聚体。复合物1/MMAO也能够将1-己烯转化为C12二聚体和C18三聚体，尽管效率很低。这些研究的机制的影响进行了讨论，并与以前的报告烯烃共三聚。
To explore the possibility of producing a narrow distribution of mid- to long-chain hydrocarbons from ethylene as a chemical feedstock, co-oligomerization of ethylene and linear α-olefins (LAOs) was investigated, using a previously reported chromium complex, [CrCl3(PNPOMe)] (1, where PNPOMe = N,N-bis(bis(o-methoxyphenyl)phosphino)methylamine). Activation of 1 by treatment with modified methylaluminoxane (MMAO) in the presence of ethylene and 1-hexene afforded mostly C6 and C10 alkene products. The identities of the C10 isomers, assigned by detailed gas chromatographic and mass spectrometric analyses, strongly support a mechanism that involves five- and seven-membered metallacyclic intermediates comprising of ethylene and LAO units. Using 1-heptene as a mechanistic probe, it was established that 1-hexene formation from ethylene is competitive with formation of ethylene/LAO co-trimers, and that co-trimers derived from one ethylene and two LAO molecules are also generated. Complex 1/MMAO is also capable of converting 1-hexene to C12 dimers and C18 trimers, albeit with poor efficiency. The mechanistic implications of these studies are discussed and compared to previous reports of olefin co-trimerization.
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影响因子：
15
作者：
Agapie, T;Schofer, SJ;Bercaw, JE
通讯作者：
Bercaw, JE
影响因子：
4.9
作者：
Carter, A;Cohen, SA;Wass, DF
通讯作者：
Wass, DF
DOI：
10.1039/c39890000674
发表时间：
1989-06-01
影响因子：
--
作者：
BRIGGS, JR
通讯作者：
BRIGGS, JR
影响因子：
2.8
作者：
Elowe, Paul R.;McCann, Cassandra;Bercaw, John E.
通讯作者：
Bercaw, John E.
影响因子：
4.9
作者：
Blann, K;Bollmann, A;Overett, MJ
通讯作者：
Overett, MJ