Chelating Diamide Based Rate Enhancement of Intramolecular Alkene Hydroaminations Catalyzed by a Neutral Sc(III) Complex
作者:Joon Young Kim、Tom Livinghouse
DOI:10.1021/ol051574h
日期:2005.9.1
[reaction: see text] Neutral scandium amido complexes are viable catalysts for intramolecular alkenehydroamination. Catalytic activity is strongly coupled to the electronic character of the Sc(III) ligand environment with chelating diamide coordination providing a precatalyst possessing substantially improved activity and superb distereoselectivity in the synthesis of trans-2,5-disubstituted pyrrolidines
Highly Efficient Ruthenium Catalysts for the Formation of Tetrasubstituted Olefins via Ring-Closing Metathesis
作者:Ian C. Stewart、Thay Ung、Alexandre A. Pletnev、Jacob M. Berlin、Robert H. Grubbs、Yann Schrodi
DOI:10.1021/ol0705144
日期:2007.4.1
[reaction: see text] A series of ruthenium-based metathesis catalysts with N-heterocyclic carbene (NHC) ligands have been prepared in which the N-aryl groups have been changed from mesityl to mono-ortho-substituted phenyl (e.g., tolyl). These new catalysts offer an exceptional increase in activity for the formation of tetrasubstituted olefins via ring-closingmetathesis (RCM), while maintaining high
Synthesis of New Bis(amidine)–Cobalt Catalysts and Their Application to Styrene Polymerization
作者:Wonseok Cho、Hyemin Cho、Chun Sun Lee、Bun Yeoul Lee、Bongjin Moon、Jahyo Kang
DOI:10.1021/om401183d
日期:2014.4.14
capability than the 1,2-diimine ligand. Upon test polymerization of styrene, the complex exhibited a moderate activity of 5.88 × 105 g PS/(mol Co h). On the basis of this encouraging result, a new 1,2-diaminobenzene-derived bis(amidine) ligand was efficiently synthesized and used to make the corresponding cobalt(II) complex. When subjected to styrene polymerization, the resulting complex showed unusually high
合理设计并有效合成了两种新的双(am)钴(II)配合物。第一个合成的钴配合物是基于具有手性邻位二苯基的环状双(am)配体。通过单晶X射线晶体学验证了该结构。正如配体结构所预期的那样,该配合物中的Co-N键比相应的1,2-二亚胺钴配合物中的Co-N键短得多。这表明双(am)配体比1,2-二亚胺配体具有更好的供电子能力。经过苯乙烯的聚合试验,该配合物的活性中等,为5.88×10 5。g PS /(摩尔Co h)。基于该令人鼓舞的结果,有效地合成了新的源自1,2-二氨基苯的双(am)配体,并用于制备相应的钴(II)配合物。当进行苯乙烯聚合时,所得络合物显示出异常高的聚合活性[164×10 5 g PS /(mol Co h)]和高转化率(> 99%)。通过13 C NMR光谱分析将所得的聚合物鉴定为无规聚苯乙烯。1,2-二氨基苯起源的双(am)钴(II)配合物的苯乙烯聚合活性显着增强归因于配体的供电子能力提高。
Organometallic ruthenium complexes and related methods for the preparation of tetra-substituted and other hindered olefins
申请人:Berlin Jacob
公开号:US20070282148A1
公开(公告)日:2007-12-06
The invention relates to ruthenium alkylidene complexes having an N-heterocyclic carbene ligand comprising a 5-membered heterocyclic ring having a carbenic carbon atom and at least one nitrogen atom contained within the 5-membered heterocyclic ring, wherein the nitrogen atom is directly attached to the carbenic carbon atom and is substituted by a phenyl ring, and wherein the phenyl ring has a hydrogen at either or both ortho positions and is substituted at at least one ortho or meta position. The invention also relates to an olefin metathesis reactions and particularly to the preparation of tetra-substituted cyclic olefins via a ring-closing metathesis.
ORGANOMETALLIC RUTHENIUM COMPLEXES AND RELATED METHODS FOR THE PREPARATION OF TETRA-SUBSTITUTED AND OTHER HINDERED OLEFINS
申请人:BERLIN Jacob
公开号:US20120123133A1
公开(公告)日:2012-05-17
The invention relates to ruthenium alkylidene complexes having an N-heterocyclic carbene ligand comprising a 5-membered heterocyclic ring having a carbenic carbon atom and at least one nitrogen atom contained within the 5-membered heterocyclic ring, wherein the nitrogen atom is directly attached to the carbenic carbon atom and is substituted by a phenyl ring, and wherein the phenyl ring has a hydrogen at either or both ortho positions and is substituted at at least one ortho or meta position. The invention also relates to an olefin metathesis reactions and particularly to the preparation of tetra-substituted cyclic olefins via a ring-closing metathesis.