1025-15-6Relevant articles and documents
Selective and Efficient Syntheses of Perhydro-1,3,5-triazine-2,4,6-triones and Carbodiimides from Isocyanates Using ZP(MeNCH2CH2)3N Catalysts
Tang, Jiansheng,Mohan, Thyagarajan,Verkade, John G.
, p. 4931 - 4938 (1994)
With concentrations as low as 0.0033 mol percent ZP(MeNCH2CH2)3N (Z = lone pair, 1) isocyanates are catalytically trimerized to perhydro-1,3,5-triazine-2,4,6-triones (isocyanurates) at room temperature.This reaction proceeds readily in the presence or absence of solvent, and the catalyst can be recycled at least six times without detectable degradation.Though not as potent a catalyst as 1, the molecule in which Z = NPh (3) also facilitates this reaction, and evidence is adduced that the catalytically active species is the adduct 3*ArNCO (6).In contrast, Ch=P(MeNCH2CH2)3N (Ch = O, 4; Ch = S, 5) selectively catalyze the transformation of isocyanates to carbodiimides and do so more efficiently than their acyclic analogues O=P(NMe2)3 and (MeO)2P(S)Ph, respectively.The crystal structure of 4 is reported for the first time, and details of the crystal structure of I reported earlier by us in preliminary form are presented.Both structures support the hypothesis that P-Nax transannulation plays a lead role in the catalytic activities of 1 and 3 - 5.
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
, p. 1520 - 1524 (2011)
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
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.
Method for synthesizing highly pure cross-linking agent triallyl isocyanurate
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Paragraph 0028-0030, (2019/01/05)
The invention discloses a method for synthesizing highly pure cross-linking agent triallyl isocyanurate. The highly pure triallyl isocyanurate is synthesized from bromopropene, cyanuric acid, a phasetransfer catalyst and a composite catalyst in a polar organic solvent, produced tail gas hydrogen bromide is fully absorbed by circulating water of asecondary graphite parallel flow falling film absorption tower, and is used into prepare certain-concentration hydrobromic acid for sale; the above synthesis reaction is carried out in the organic medium instead of a strong alkaline aqueous solution,so generation of a large amount of wastewater containing organic matters and salts is avoided, and treatment and processing of high-concentration wastewater and waste residues are avoided; and the finally obtained reaction solution is desolvated to obtain the highly pure TAIC with a content of 99.0% or above.
