The reaction of potassium tellurocyanate (prepared in situ) with N-(1-chloroethylidene)arylamines (i.e., 4-RC6H4N = C(CH3)Cl, where R = H, Cl, CH3 and NO2) in DMSO solution gave unexpectedly, after hydrolysis, the corresponding N-(3-(arylamino)butan-2-ylidene)arylamines in 63-78%. Reaction of N-(3-(arylamino)butan-2-ylidene)arylamines with SOCl2 or with Br-2 resulted in the substitution of a halogen on the aromatic rings. The presence of a water molecule within the structure of the synthesized diimines was rationalized theoretically by Density Functional Theory (DFT). All compounds were characterized by elemental analysis, IR, NMR and mass spectroscopic data.
Solvent effect on the sensitized photooxygenation of cyclic and acyclic α-diimines
作者:Else Lemp、Antonio L. Zanocco、German Günther、Nancy Pizarro
DOI:10.1016/j.tet.2006.08.091
日期:2006.11
The reaction of singlet molecular oxygen with a series of cyclic and acyclic α-diimines was studied. Time-resolved methods were used to measure total reaction rate constants and steady-state methods were used to determine chemicalreaction rate constants. GC–MS was used to tentatively assign the reaction products. 5,6-Disubstituted cyclic α-diimines are singlet oxygen quenchers, but become more effective
Ruthenium‐Catalyzed Dehydrogenation Through an Intermolecular Hydrogen Atom Transfer Mechanism
作者:Lin Huang、Alessandro Bismuto、Simon A. Rath、Nils Trapp、Bill Morandi
DOI:10.1002/anie.202015837
日期:2021.3.22
The direct dehydrogenation of alkanes is among the most efficient ways to access valuable alkene products. Although several catalysts have been designed to promote this transformation, they have unfortunately found limited applications in fine chemical synthesis. Here, we report a conceptually novel strategy for the catalytic, intermolecular dehydrogenation of alkanes using a ruthenium catalyst. The combination
Mechanistic Studies of Single-Step Styrene Production Catalyzed by Rh Complexes with Diimine Ligands: An Evaluation of the Role of Ligands and Induction Period
作者:Weihao Zhu、Zhongwen Luo、Junqi Chen、Chang Liu、Lu Yang、Diane A. Dickie、Naiming Liu、Sen Zhang、Robert J. Davis、T. Brent Gunnoe
DOI:10.1021/acscatal.9b01480
日期:2019.8.2
catalytic benzene alkenylation using different diimine ligated Rh(I) acetatecomplexes and Cu(OAc)2 as the oxidant revealed statistically identical results in terms of activity and product selectivity. Under ethylene pressure, two representative diimine ligated rhodium(I) acetatecomplexes were demonstrated to exchange the diimine ligand with ethylene rapidly to form [Rh(μ-OAc)(η2-C2H4)2]2 and free diimine
使用不同的二亚胺连接的乙酸Rh(I)络合物和Cu(OAc)2作为氧化剂的催化苯烯基化反应的研究表明,就活性和产物选择性而言,统计学上相同的结果。下的乙烯压力,两个代表性二亚胺连接铑(I)配合物乙酸被证明与乙烯迅速交换二亚胺配体与形式的[Rh(μ-OAC)(η 2 -C 2 H ^ 4)2 ] 2和自由二亚胺。因此,得出的结论是,在催化条件下,二亚胺配体不太可能与活性Rh催化剂配位。在使用市售的铜(OAC)催化条件下150℃ 2作为氧化剂时,铑[Rh(μ-OAC)(η 2-C 2 H 4)2 ] 2经历快速分解以形成催化惰性和不溶性Rh物质,然后逐渐溶解不溶性Rh形成可溶Rh,对苯乙烯生产具有活性。因此,在某些条件下观察到的诱导期很可能是由于形成不溶的Rh(快速),然后再溶解Rh(缓慢)所致。通过使用已预热的可溶性Cu(II)氧化剂或Cu(OAc)2,可以抑制Rh的分解过程并保持催化活性Rh
Electrophilic RhI catalysts for arene H/D exchange in acidic media: Evidence for an electrophilic aromatic substitution mechanism
作者:Michael S. Webster-Gardiner、Paige E. Piszel、Ross Fu、Bradley A. McKeown、Robert J. Nielsen、William A. Goddard、T. Brent Gunnoe
DOI:10.1016/j.molcata.2016.07.045
日期:2017.1
of new rhodium (I) complexes supported by bidentate nitrogen-donor ligands with varying electronic and steric properties were synthesized in situ and evaluated for catalyticarene C–H/D activation. In trifluoroacetic acid (HTFA), these complexes are proposed to mediate H/D exchange of arene C–H/D bonds by an electrophilic aromatic substitution mechanism that involves Rh-mediated activation of HTFA
[EN] RUTHENIUM OLEFIN METATHESIS CATALYSTS BEARING N-HETEROCYCLIC CARBENE LIGANDS WITH SUBSTITUTED BACKBONE<br/>[FR] CATALYSEURS DE MÉTATHÈSE D'OLÉFINES À BASE DE RUTHÉNIUM PORTANT DES LIGANDS CARBÈNES N-HÉTÉROCYCLIQUES À SQUELETTE SUBSTITUÉ
申请人:MATERIA INC
公开号:WO2009126831A1
公开(公告)日:2009-10-15
This invention relates generally to olefin metathesis, more particularly, to tri- or tetra-substituted imidazoliniυm salts which are precursors to N-heterocyclic carbene (NHC) ligands with tri- or tetra-substituted irnidazolinium rings, organometallic ruthenium complexes comprising gem di-substituted imidazoiinium NHC ligands, organometallic ruthenium complexes comprising tri- or tetra-substituted imidazoiinium NHC ligands, and to olefin metathesis methods using them. The catalysts and methods of the invention have utility in the fields of catalysis, organic synthesis, and industrial chemistry.