Z-Selective and Syndioselective Ring-Opening Metathesis Polymerization (ROMP) Initiated by MonoAryloxidePyrrolide (MAP) Catalysts.
Z-Selective and Syndioselective Ring-Opening Metathesis Polymerization (ROMP) Initiated by MonoAryloxidePyrrolide (MAP) Catalysts.
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DOI：
10.1021/ma101375v
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发表时间：
2010-09-28
期刊：
影响因子：
5.5
通讯作者：
Schrock RR
中科院分区：
文献类型：
--
作者：
Flook MM;Gerber LC;Debelouchina GT;Schrock RR
本文报道了以钼为催化剂的单芳氧吡咯烷亚胺烷叉（MAP）催化2，3-双（三氟甲基）双环[2.2.1]庚-2，5-二烯（NBDF 6）和3-甲基-3-苯基环丙烯（MPCP）的Z-选择性和间位选择性聚合。以顺式Mo（NAd）（CHCMe_2Ph）（Pyr）（OHIPT）（1; Ad = 1-金刚烷基，OHIPT = O-2，6-（2，4，6-i-Pr_3C_6 H_2）_2C_6H_3）为引发剂的聚合反应机理是单体加成到顺式引发剂中，生成顺式第一插入产物，并通过顺式插入产物进行聚合。相比之下，在-78 °C下以顺式Mo（NAr）（CHCMe 2 Ph）（Pyr）（OTPP）（4; Ar = 2，6-i-Pr 2C 6 H3，OTPP = 2，3，5，6-Ph 4C 6 H）作为引发剂的聚合反应机理包括向顺式引发剂中加入单体以产生反第一插入产物和通过反插入产物的增长。4引发的NBDF 6和MPCP在室温下的聚合导致聚合物没有规则的结构。我们提出顺式聚合物的间同立构规整度是每次插入单体时金属中心所需的反转的结果，即，聚合物结构的立体金属控制。我们还提出，形成顺式，间同立构聚合物的两种机制出现作为一个后果的相对空间体积的酰亚胺和酚盐配体。
We report the Z-selective and syndioselective polymerization of 2,3-bis(trifluoromethyl)bicyclo[2.2.1]hepta-2,5-diene (NBDF6) and 3-methyl-3-phenylcyclopropene (MPCP) by monoaryloxide monopyrrolide imido alkylidene (MAP) catalysts of Mo. The mechanism of polymerization with syn-Mo(NAd)(CHCMe2Ph)(Pyr)(OHIPT) (1; Ad = 1-adamantyl, OHIPT = O-2,6-(2,4,6-i-Pr3C6H2)2C6H3) as the initiator is proposed to consist of addition of monomer to the syn initiator to yield a syn first insertion product and propagation via syn insertion products. In contrast, the mechanism of polymerization with syn-Mo(NAr)(CHCMe2Ph)(Pyr)(OTPP) (4; Ar = 2,6-i-Pr2C6H3, OTPP = 2,3,5,6-Ph4C6H) as the initiator at −78 °C consists of addition of monomer to the syn initiator to yield an anti first insertion product and propagation via anti insertion products. Polymerizations of NBDF6 and MPCP at room temperature initiated by 4 led to polymers without a regular structure. We propose that the syndiotacticity of cis polymers is the consequence of the required inversion at the metal center with each insertion of monomer, i.e., stereogenic metal control of the polymer structure. We also propose that the two mechanisms for forming cis,syndiotactic polymers arise as a consequence of the relative steric bulk of the imido and phenoxide ligands.
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影响因子：
15
作者：
Flook, Margaret M.;Jiang, Annie J.;Schrock, Richard R.;Mueller, Peter;Hoveyda, Amir H.
通讯作者：
Hoveyda, Amir H.
影响因子：
5.5
作者：
Binder, Wolfgang H.;Kurzhals, Steffen;Buchmeiser, Michael R.
通讯作者：
Buchmeiser, Michael R.
影响因子：
4.9
作者：
Broeders, J;Feast, WJ;Khosravi, E
通讯作者：
Khosravi, E
影响因子：
4.6
作者：
DAVIES, GR;HUBBARD, HVS;MARSHALL, EL
通讯作者：
MARSHALL, EL
影响因子：
15
作者：
Jiang, Annie J.;Simpson, Jeffrey H.;Schrock, Richard R.
通讯作者：
Schrock, Richard R.