19045-26-2Relevant academic research and scientific papers
Synergistic Catalysis by Br?nsted Acid/Carbodicarbene Mimicking Frustrated Lewis Pair-Like Reactivity
Bai, Yuna,Chan, Yi-Chen,Chen, Hsing-Yin,Chen, Hsuan-Ying,Chen, Wen-Ching,Li, Chen-Yu,Ong, Tiow-Gan,Tseng, Mei-Chun,Wu, Ying-Yann,Yap, Glenn P. A.,Zhao, Lili
supporting information, p. 19949 - 19956 (2021/08/03)
Carbodicarbene (CDC), unique carbenic entities bearing two lone pairs of electrons are well-known for their strong Lewis basicity. We demonstrate herein, upon introducing a weak Br?nsted acid benzyl alcohol (BnOH) as a co-modulator, CDC is remolded into a Frustrated Lewis Pair (FLP)-like reactivity. DFT calculation and experimental evidence show BnOH loosely interacting with the binding pocket of CDC via H-bonding and π-π stacking. Four distinct reactions in nature were deployed to demonstrate the viability of proof-of-concept as synergistic FLP/Modulator (CDC/BnOH), demonstrating enhanced catalytic reactivity in cyclotrimerization of isocyanate, polymerization process for L-lactide (LA), methyl methacrylate (MMA) and dehydrosilylation of alcohols. Importantly, the catalytic reactivity of carbodicarbene is uniquely distinct from conventional NHC which relies on only single chemical feature of nucleophilicity. This finding also provides a new spin in diversifying FLP reactivity with co-modulator or co-catalyst.
Yttrium dialkyl supported by a silaamidinate ligand: Synthesis, structure and catalysis on cyclotrimerization of isocyanates
Liu, Deshuai,Zhou, Dahai,Yang, Hao,Li, Jianfeng,Cui, Chunming
supporting information, p. 12324 - 12327 (2019/10/19)
A sterically demanding silaamidine (ArN = Si(L)NHAr) ligand was synthesized and employed for the preparation of a yttrium dialkyl complex, which catalytically enabled the cyclotrimerization of isocyanate with high activity and excellent functional group t
Potassium complexes containing bidentate pyrrole ligands: Synthesis, structures, and catalytic activity for the cyclotrimerization of isocyanates
Guo, Zhiqiang,Xu, Yuan,Wu, Xiaoqin,Wei, Xuehong,Xi, Chanjuan
supporting information, p. 8116 - 8121 (2019/06/19)
Bidentate pyrrolyl ligands, 2-(t-butyliminomethyl)pyrrole and 2-(t-butylaminomethyl)pyrrole, reacted with KH to give complexes [C4H3N(2-CHNtBu)K(THF)]n (1) and [C4H3N(2-CH2NHsup
Highly efficient cyclotrimerization of isocyanates using N-heterocyclic olefins under bulk conditions
Li, Chengkai,Zhao, Wuchao,He, Jianghua,Zhang, Yuetao
supporting information, p. 12563 - 12566 (2019/10/28)
With a catalyst loading as low as 0.005%, high to excellent yields of isocyanurates could be achieved from N-heterocyclic olefin mediated organocatalytic cyclotrimerization of a wide range of isocyanates under bulk conditions. Experimental details coupled with structural characterization of the key intermediates led to comprehensive mechanistic studies of cyclotrimerization.
Developing catalytic applications of cooperative bimetallics: Competitive hydroamination/trimerization reactions of isocyanates catalysed by sodium magnesiates
Hernan-Gomez, Alberto,Bradley, Tyne D.,Kennedy, Alan R.,Livingstone, Zoe,Robertson, Stuart D.,Hevia, Eva
supporting information, p. 8659 - 8661 (2013/09/23)
Mixed-metal reagents [NaMg(CH2SiMe3)3] (1) and [(THF)NaMg(NPh2)3(THF)] [3-(THF)2] can act as precatalysts to selectively promote the hydroamination/trimerization of isocyanates (RNCO) depen
Atropisomers of hindered triarylisocyanurates: Structure, conformation, stereodynamics, and absolute configuration
Lunazzi, Lodovico,Mancinelli, Michele,Mazzanti, Andrea
experimental part, p. 3373 - 3380 (2012/06/04)
The syn and anti diastereoisomers of some 1,3,5-triarylisocyanurate derivatives were isolated and their configuration assigned by NOE experiments and by X-ray diffraction. The kinetics of the syn/anti interconversion were determined, and the experimental
Amine-linked N-heterocyclic carbenes: The importance of an pendant free-amine auxiliary in assisting the catalytic reaction
Li, Chia-Yi,Kuo, Yi-Yin,Tsai, Jie-Hong,Yap, Glenn P. A.,Ong, Tiow-Gan
supporting information, p. 1520 - 1524 (2013/01/11)
We have successfully expanded the library of amino-NHCs with varying substituents on the amine group, leading to insight about the instability of NHCs arising from the intermolecular interaction of the dangling amine side-arm. However, the pendant amine plays an important role with respect to the catalytic process, resuscitating the catalytic activity of unsaturated NHC's through a synergistic effect invoked by the secondary amine. This proof of concept allows us to expand the spectrum of catalysis to C-C, as well as C-B bond formation. Copyright
Organocatalytic, rapid and facile cyclotrimerization of isocyanates using tetrabutylammonium phthalimide-N-oxyl and tetraethylammonium 2-(carbamoyl)benzoate under solvent-free conditions
Dekamin, Mohammad G.,Varmira, Kambiz,Farahmand, Mehdi,Sagheb-Asl, Solmaz,Karimi, Zahra
experimental part, p. 226 - 230 (2011/09/14)
Tetrabutylammonium phthalimide-N-oxyl and tetraethylammonium 2-(carbamoyl)benzoate were found to be effective and easily accessible organocatalysts for selective cylotrimerization of aryl and alkyl isocyanates under mild reaction conditions. The reaction proceeds smoothly using very low catalyst loadings of these metal-free organocatalysts (0.025 and 0.25 mol%, respectively) under solvent-free conditions at room temperature within a very short reaction time.
N-heterocyclic carbenes as highly efficient catalysts for the cyclotrimerization of isocyanates
Duong, Hung A.,Cross, Michael J.,Louie, Janis
, p. 4679 - 4681 (2007/10/03)
(Chemical Equation Presented) A series of N-heterocyclic carbenes (NHCs) were evaluated as potential catalysts for the cyclotrimerization of isocyanates to afford isocyanurates. 1,3-Bis-(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2- ylidene (SIPr) was found to be a highly efficient catalyst for the cyclotrimerization of a variety of isocyanates.
