A C2-Symmetric, Living α-Diimine Ni(II) Catalyst: Regioblock Copolymers from Propylene
摘要:
An isomerically pure, C2-symmetric Ni(II) complex was synthesized and found to be living for propylene polymerization. The regioselectivity of the catalyst varied greatly with reaction temperature, with regioregular, highly isotactic polypropylene (PP) produced at low temperatures, and regioirregular PP produced at high temperatures. Regioblock PP was formed by changing the reaction temperature during the polymerization.
Semi‐Crystalline Polar Polyethylene: Ester‐Functionalized Linear Polyolefins Enabled by a Functional‐Group‐Tolerant, Cationic Nickel Catalyst
作者:Brian K. Long、James M. Eagan、Michael Mulzer、Geoffrey W. Coates
DOI:10.1002/anie.201601703
日期:2016.6.13
A dibenzobarrelene‐bridged, α‐diimine NiII catalyst (rac‐3) was synthesized and shown to have exceptional behavior for the polymerization of ethylene. The catalyst afforded high molecular weight polyethylenes with narrow dispersities and degrees of branching much lower than those made by related α‐diimine nickel catalysts. Catalyst rac‐3 demonstrated living behavior at room temperature, produced linear
合成了一种二苯并戊烯桥联的α-二亚胺Ni II催化剂(rac - 3),并显示出对乙烯聚合具有优异的性能。与相关的α-二亚胺镍催化剂相比,该催化剂提供的高分子量聚乙烯具有较窄的分散度和较低的支化度。催化剂rac - 3表现出在室温下的生活行为,在-20°C时产生线性聚乙烯(T m = 135°C),最重要的是能够使乙烯与可生物再生的极性单体10-十一碳烯酸甲酯共聚线性酯官能化聚乙烯。
Acid-Catalyzed <i>ortho</i>-Alkylation of Anilines with Styrenes: An Improved Route to Chiral Anilines with Bulky Substituents
作者:Anna E. Cherian、Gregory J. Domski、Jeffrey M. Rose、Emil B. Lobkovsky、Geoffrey W. Coates
DOI:10.1021/ol051916j
日期:2005.11.1
[reaction: see text] Reaction of para-substituted anilines with styrene derivatives at elevated temperatures, when catalyzed by CF3SO3H, results in highly chemoselective ortho-alkylation of the aniline. When R = H, dialkylation can be achieved by varying the ratio of styrene to aniline. Several different substituted anilines and styrenes were examined, and good yields (42-87%) were obtained, except
A <i>C</i><sub>2</sub>-Symmetric, Living α-Diimine Ni(II) Catalyst: Regioblock Copolymers from Propylene
作者:Anna E. Cherian、Jeffrey M. Rose、Emil B. Lobkovsky、Geoffrey W. Coates
DOI:10.1021/ja0540021
日期:2005.10.1
An isomerically pure, C2-symmetric Ni(II) complex was synthesized and found to be living for propylene polymerization. The regioselectivity of the catalyst varied greatly with reaction temperature, with regioregular, highly isotactic polypropylene (PP) produced at low temperatures, and regioirregular PP produced at high temperatures. Regioblock PP was formed by changing the reaction temperature during the polymerization.