1784-98-1Relevant articles and documents
Fast cyclotrimerization of a wide range of isocyanates to isocyanurates over acid/base conjugates under bulk conditions
Cheng, Ruihua,Liu, Wei,Wu, Li,Ye, Jinxing
, (2020)
An array of organic bases DMAP (4-dimethylaminopyridine), DBU (1, 8-diazabicyclo [5.4.0] undec-7-ene), TBD (1, 5, 7-triazabicyclo [4.4.0] dec-5-ene), and their base/acid conjugate organocatalyst systems were evaluated in the trimerization of various isocyanates. The performance depended greatly on the combination of the catalyst systems, and the [HTBD][OAc] (acetic acid) catalyst systems were considerably the most active in contrast to the corresponding DMAP and DBU counterparts. The [HTBD][OAc] catalyst system was capable of providing isocyanurates from the cyclotrimerization of various isocyanate substrates in excellent yields in seconds even under bulk conditions. A bifunctional catalytic mechanism over [HTBD][OAc] was proposed.
Efficient and selective trimerization of aryl and alkyl isocyanates catalyzed by sodium p-toluenesulfinate in the presence of TBAI in a solvent-free condition
Moghaddam, Firouz Matloubi,Dekamin, Mohammad G.,Khajavi, Mohammad S.,Jalili, Seifollah
, p. 851 - 852 (2002)
Aryl and alkyl isocyanates have been efficiently converted into symmetrical trisubstituted aryl and alkyl isocyanurates, catalyzed by sodium p-toluenesulfinate on its own or in the presence of tetrabutylammonium iodide (TBAI), in a solvent-free condition.
Macrocyclic complexes containing a platinacycle or palladacycle composed of an isocyanate dimer unit: Reactivity towards isocyanides and cyclotrimerization of isocyanates
Choi, Jun-Hwan,Jung, Kang-Yeoun,Kim, Yong-Joo,Im, Hye Jin,Lee, Soon W.
, p. 283 - 292 (2016)
The reactions of [Pt(styrene)(PMe3)2] with 2 equiv. of alkyl or aryl isocyanate affored five-membered platinacycles, cis-[Pt{-N(R)C(O)N(R)C(O)-}(PMe3)2] (R = CH2C6H5, p-ClC6H4, p-OMeC6H4). These complexes are the first examples of platinacycles containing an isocyanate dimer unit. When the five-membered bis(phosphine) platinacycles or palladacycles were treated with 2 equiv. of elemental sulfur, 16-membered cyclic products as an assembly of four platinacycles or palladacycles, [M(PR3){-N(R)C(O)N(R)C(O)-}]4, were readily obtained. These cyclic tetramers were cleaved using tert-butyl isocyanide (CN-tbutyl, 4 equiv.), affording the corresponding monomeric complexes, [M(PR3)(CN-tbutyl){-N(R)C(O)N(R)C(O)-}] (M = Pt, Pd). An unusual cyclotrimerization of organic isocyanates catalyzed by zerovalent Pt complexes or five-membered platinacycles was observed. In addition, the direct cyclotrimerization of alkyl or aryl isocyanates using dialkyl Pt(II) or Pd(II) complexes was investigated. The cross cyclotrimerization of an aryl isocyanate and its derivative using a zerovalent Pd complex was also investigated.
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
, p. 8116 - 8121 (2019)
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
Combination of sulfite anion and Phase Transfer Catalysts for green cyclotrimerization of aryl isocyanates
Dekamin, Mohammad G.,Mallakpour, Shadpour,Ghassemi, Maryam
, p. 427 - 434 (2005)
The catalytic cyclotrimerization of aryl and alkyl isocyanates by the novel combination catalysts of sulfite ion and Phase Transfer Catalysts (PTCs), as selective anionic catalysts, has been investigated. The use of phase transfer catalyst features the ca
Lithium complex of 2-amino-functionalized benzoylpyrrole: Synthesis, structure, and catalytic activity for the cyclotrimerization of isocyanates
Guo, Zhiqiang,Wang, Yakong,Yang, Jihong,Wei, Xuehong
, p. 13 - 17 (2017)
Lithium complex stabilised by 2-amino-functionalized benzoylpyrrole was synthesized, and its structural features were provided. The molecular structure shows a novel tetrameric cage structure, which includes a eight-membered (LiN)4 ring and a e
Tridentate pyrrolylzinc compounds: Synthesis, structures, reactivities and catalytic cyclotrimerization reaction of isocyanate
Guo, Zhiqiang,Wei, Xuehong,Tong, Hongbo,Liu, Diansheng
, p. 136 - 142 (2015)
The reactions of ZnEt2 with NNN-tridentate pincer type pyrrolyl ligands, 2,5-bis((dimethylamino)methylene)-1H-pyrrole (HL1), 2,5-bis((pyrrolidin-1-yl)methylene)-1H-pyrrole (HL2) and 2,5-bis((piperidino)methylene)-1H-pyrrol
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
Aluminium-catalysed isocyanate trimerization, enhanced by exploiting a dynamic coordination sphere
Bahili, Mohammed A.,Stokes, Emily C.,Amesbury, Robert C.,Ould, Darren M. C.,Christo, Bashar,Horne, Rhian J.,Kariuki, Benson M.,Stewart, Jack A.,Taylor, Rebekah L.,Williams, P. Andrew,Jones, Matthew D.,Harris, Kenneth D. M.,Ward, Benjamin D.
supporting information, p. 7679 - 7682 (2019/07/08)
Main-group metals are inherently labile, hindering their use in catalysis. We exploit this lability in the synthesis of isocyanurates. For the first time we report a highly active catalyst that trimerizes alkyl, allyl and aryl isocyanates, and di-isocyanates, with low catalyst loadings under mild conditions, using a hemi-labile aluminium-pyridyl-bis(iminophenolate) complex.
