1034137-26-2Relevant academic research and scientific papers
The p: K a values of N-aryl imidazolinium salts, their higher homologues, and formamidinium salts in dimethyl sulfoxide
Cole, Marcus L.,Dunn, Michelle H.,Harper, Jason B.,Konstandaras, Nicholas,Luis, Ena T.
, p. 1910 - 1917 (2020/03/23)
A series of imidazolinium salts, their six-, seven- A nd eight-membered homologues, and the related formamidinium salts were prepared, and their pKa values were determined in DMSO at 25 °C using the bracketing indicator method. The effect of each type of structural variation on the acidity of each salt was considered, particularly noting the importance of ring size and the effect of the steric and electronic nature of the N-aryl substituents. The effect of a cyclic structure was also probed through comparing the cyclic systems with the corresponding formamidinium salts, noting the importance of conformational flexibility in the latter cases. Along with allowing choice of appropriate bases for deprotonation of these species, it is anticipated that the data presented will aid in the understanding of the nucleophilicity, and potentially catalytic efficacy, of the corresponding carbenes.
Anionic ring-opening homo- and copolymerization of lactams by latent, protected N-heterocyclic carbenes for the preparation of PA 12 and PA 6/12
Naumann, Stefan,Schmidt, Friedrich Georg,Speiser, Maria,Boehl, Margit,Epple, Stefan,Bonten, Christian,Buchmeiser, Michael R.
, p. 8426 - 8433 (2013/12/04)
Laurolactam (LL) is polymerized in the bulk using strongly basic N-heterocyclic carbenes (NHCs) as initiators at temperatures of 180-200 C to prepare the corresponding polyamide (PA 12). In-situ rheology of the polymerization progress reveals that an anionic mechanism is active, which is supported by the strong dependence of initiator activity on the basicity of the NHCs. GPC data and kinetic investigations show the process to be moderately controlled and fast, allowing high or quantitative yields in short polymerization times. Fifteen different NHC-CO2-adducts and NHC-metal complexes were used as thermally labile but room temperature stable NHC-precursors. Depending on the ring size and N-substituent, some of these protected NHCs allow forming a mixture of monomer and NHC-precursor that is suitable for long-term storage and readily polymerizable by simple heating. All polymerizations are executed without activator or other additives and thus represent a true one-component system for the production of PA 12. Finally, LL is copolymerized with ε-caprolactam (ε-CLA). It is found that a copolymer with a considerable gradient is formed, with ε-CLA being incorporated preferentially at the onset of the polymerization.
Expanded ring N-heterocyclic carbene complexes of zero valent platinum dvtms (divinyltetramethyldisiloxane): Highly efficient hydrosilylation catalysts
Dunsford, Jay J.,Cavell, Kingsley J.,Kariuki, Benson
experimental part, p. 188 - 194 (2011/02/16)
The synthesis and characterisation of a series of new 6- and 7-membered NHC (N-heterocyclic carbene) complexes 7-12 of zero valent platinum dvtms (divinyltetramethyldisiloxane), [Pt(NHC)(dvtms)] are reported. A number of the complexes were investigated as catalyst precursors in the hydrosilylation of a range of unsaturated substrates, including alkynes, alkenes and a ketone with triethylsilane and bis(trimethylsiloxy)methylsilane (MD'M), at low catalyst loading (0.005 mol %); in general, the activity, and the selectivity for 1-functionalised product was found to be high.
Structure and bonding in neutral and cationic 14-electron gold alkyne π complexes
Fluegge, Susanne,Anoop, Anakuthil,Goddard, Richard,Thiel, Walter,Fuerstner, Alois
experimental part, p. 8558 - 8565 (2010/03/31)
Cyclododecyne (5) as a prototype unstrained alkyne was coordinated to either the neutral [AuCl] fragment or to two different cationic [Au(NHQ] + entities (NHC = N-heterocyclic carbene), and the resulting complexes 6, 8, and 10 were characterize
Six- and seven-membered ring carbenes: Rational synthesis of amidinium salts, generation of carbenes, synthesis of Ag(I) and Cu(I) complexes
Kolychev, Eugene L.,Portnyagin, Ivan A.,Shuntikov, Viacheslav V.,Khrustalev, Victor N.,Nechaev, Mikhail S.
experimental part, p. 2454 - 2462 (2009/10/09)
Reactions of neat 1,3- and 1,4-dibromides with N,N′-diarylformamidines in the presence of diisopropylethylamine (DIPEA) afford corresponding amidinium salts in high yields (>80%). Six- and seven-membered ring amidinium salts bearing bulky Mes (2,4,6-Mesu
