258278-25-0Relevant academic research and scientific papers
Application of Quantitative 1H and 19F NMR to Organometallics
Akhdar, Ayman,Andanson, Jean-Michel,Faure, Sophie,Gautier, Arnaud,Tra?kia, Mounir
, (2021/08/03)
Purity assessment of organometallics is particularly important for catalytic applications. While quantitative NMR is a well-known method in pharmaceutic chemistry, the present work illustrates its usefulness for the determination of the ligands and organometallics purities using proton and fluorine NMR. This method is fast, straightforward and provides accuracy results.
Mechanism studies of oxidation and hydrolysis of Cu(I)–NHC and Ag–NHC in solution under air
Li, Dazhi,Ollevier, Thierry
supporting information, (2019/11/29)
The decomposition of copper(I)–NHC and silver-NHC complexes in solution under air was studied. The Cu(I)–NHCs were oxidized into urea derivatives and hydrolysed into imidazoliums or benzimidazoliums. The decomposition of Ag–NHC with a saturated backbone led to ring-opening product, while the Ag–NHC with an unsaturated backbone led to imidazolium and Ag-bisNHC complex. The effects of steric property, hydrophilicity, and binding energy of NHC to O2 and H2O on the decomposition of Cu(I)–NHC were studied using theoretical calculations. Steric hindrance played an important role on the stability of Cu(I)–NHC. Pathways for the decomposition of Cu(I)–NHC and Ag–NHC were proposed.
Synthesis of Imidazolidinone, Imidazolone, and Benzimidazolone Derivatives through Oxidation Using Copper and Air
Li, Dazhi,Ollevier, Thierry
supporting information, p. 3572 - 3575 (2019/05/24)
A new synthetic method of urea derivatives using copper and air was developed. These mild conditions provided moderate to very good yields for 15 examples (53-93%), while low yields were obtained with sterically hindered substrates (3 examples). The reaction was found to go through an in situ generated copper-N-heterocyclic carbene, which was then oxidized into cyclic urea derivatives possessing alkyl, benzyl, aryl, hydroxy, Boc-protected, and tertiary amine groups.
Mechanochemistry for facilitated access to N,N-diaryl NHC metal complexes
Beillard, Audrey,Bantreil, Xavier,Métro, Thomas-Xavier,Martinez, Jean,Lamaty, Frédéric
, p. 1057 - 1063 (2017/02/10)
A user-friendly and solvent-free mechanosynthetic strategy allowed light-sensitive silver(i) complexes featuring N,N-diaryl N-heterocyclic carbenes (NHC), including challenging and sterically hindered ligands, to be yielded efficiently. The first transmet
Oxygen-atom insertion of NHCecopper complex: The source of oxygen from N, N-dimethylformamide
Zeng, Wei,Wang, Enyu,Qiu, Rui,Sohail, Muhammad,Wu, Shaoxiang,Chen, Fu-Xue
supporting information, p. 44 - 48 (2013/10/08)
An unprecedented protocol for oxygen-atom insertion reaction of NHCecopper complexes has been developed by employing N,N-dimethylformamide as the oxygen source, which allows the preparation of imidazolinones from carbene complexes and decodes one of the m
A direct and practical approach for the synthesis of N-heterocyclic carbene coinage metal complexes
Zhu, Shifa,Liang, Renxiao,Jiang, Huanfeng
, p. 7949 - 7955 (2012/09/22)
A novel direct and practical synthetic route leading to N-heterocyclic carbene coinage metal complexes has been developed by using air stable, commercial available Au(III) salt [MAuCl4·2H2O], CuCln (n=1,2) or AgCl, and imidazolium salts as starting materials. The reaction proceeded without sacrificing carbene transfer agent (Ag 2O) or using highly sensitive free NHC.
PKas of the conjugate acids of N-heterocyclic carbenes in water
Higgins, Eleanor M.,Sherwood, Jennifer A.,Lindsay, Anita G.,Armstrong, James,Massey, Richard S.,Alder, Roger W.,O'Donoghue, Annmarie C.
, p. 1559 - 1561 (2011/03/22)
pKa values of 19.8-28.2 are reported for the conjugate acids of a large series of NHCs in water. The effects of ring size, N-substituent and C(4)-C(5) saturation on pKa are discussed.
PREPARATION OF SATURATED IMIDAZOLINIUM SALTS AND RELATED COMPOUNDS
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Page/Page column 11; 19-20, (2009/06/27)
Methods for the preparation of saturated imidazolinium salts and related compounds that comprises reaction of formamidines with compounds such as dihaioethane and an optional base are disclosed. Alternatively, the imidazoünium salts and related compounds can be prepared in a one-step process without purification of the formamidine reactant. These methods make it possible to obtain numerous imidazolinium salts and related compounds under solvent-free reaction conditions and in excellent yields.
A facile preparation of imidazolinium chlorides
Kuhn, Kevin M.,Grubbs, Robert H.
supporting information; experimental part, p. 2075 - 2077 (2009/04/10)
A process for the preparation of symmetric and unsymmetric imidazolinium chlorides that involves reaction of a formamidine with dichloroethane and a base (a) is described. This method makes it possible to obtain numerous imidazolinium chlorides under solvent-free reaction conditions and in excellent yields with purification by simple filtration. Alternatively, symmetric imidazolinium chlorides can be prepared directly in moderate yields from substituted anilines by utilizing half of the formamidine Intermediate as sacrificial base (b).
Probing the efficiency of N-heterocyclic carbene promoted O- to C-carboxyl transfer of oxazolyl carbonates
Thomson, Jennifer E.,Campbell, Craig D.,Concellon, Carmen,Duguet, Nicolas,Rix, Kathryn,Slawin, Alexandra M. Z.,Smith, Andrew D.
, p. 2784 - 2791 (2008/09/20)
(Chemical Equation Presented) Screening of a range of azolium salts, bases and solvents for reactivity indicates that triazolinylidenes, generated in situ with KHMDS in THF, promote the Steglich rearrangement of oxazolyl carbonates with high catalytic efficiency (typical reaction time 5 min at 1.5 mol % NHC). This protocol shows wide substrate applicability, even allowing the efficient generation of vicinal quaternary centers. An improved experimental procedure is also described that allows a simplified one-pot reaction protocol to be employed with similarly high catalytic efficiency.
