141556-42-5

Basic information

• Product Name: 1,3-BIS(2,4,6-TRIMETHYLPHENYL)IMIDAZOL-2-YLIDENE
• Synonyms: 1,3-BIS(2,4,6-TRIMETHYLPHENYL)IMIDAZOL-2-YLIDENE;1,3-Bis(2,4,6-trimethylphenyl)imidazol-2-ylidene,min.98%;1,3-BIS(2,4,6-TRIMETHYLPHENYL)IMIDAZOL-2-YLIDENE, MIN. 98%;1,3-Bis(2,4,6-trimethylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene;1,3-Dimesitylimidazol-2-ylidene;IMes;1,3-Bis(2,4,6-triMethylphenyl)-1,3-dihydro-2H-iMidazol-2-yli;2H-IMidazol-2-ylidene, 1,3-dihydro-1,3-bis(2,4,6-triMethylphenyl)-
• CAS NO: 141556-42-5
• Molecular Formula: C₂₁H₂₄N₂
• Molecular Weight: 304.42866
• Product Categories: N-heterocyclic carbene
• Mol File: 141556-42-5.mol
• Article Data: 25

Chemical Properties

• Melting Point: 140 °C
• Boiling Point: 442.706°C at 760 mmHg
• Flash Point: 199.09°C
• Appearance: white to off-white/Powder
• Vapor Pressure: 0mmHg at 25°C
• Storage Temp.: ?20°C
• Sensitive: air sensitive, moisture sensitiv
• CAS DataBase Reference: 1,3-BIS(2,4,6-TRIMETHYLPHENYL)IMIDAZOL-2-YLIDENE(CAS DataBase Reference)
• NIST Chemistry Reference: 1,3-BIS(2,4,6-TRIMETHYLPHENYL)IMIDAZOL-2-YLIDENE(141556-42-5)
• EPA Substance Registry System: 1,3-BIS(2,4,6-TRIMETHYLPHENYL)IMIDAZOL-2-YLIDENE(141556-42-5)

Safety Data

• Hazard Codes: Xi
• Statements: 10-36/37/38
• Safety Statements: 26
• RIDADR: UN 1325 4.1/PG 3
• WGK Germany: 3
• Hazardous Substances Data: 141556-42-5(Hazardous Substances Data)

Usage

Reaction

Nucleophilic carbene that serves as a bulky, electron-rich "phosphine mimic" for metal-catalyzed reactions. (a) Palladium-catalyzed Suzuki cross-coupling of aryl chlorides. (b) Ruthenium-carbene complexes serve as more reactive catalyst for ring-closing metathesis.

Uses

1,3-Bis(2,4,6-trimethylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene (IMes) is a nucleophilic N-heterocyclic carbene (NHC) ligand.It can be used to synthesize: IMes ligated-rhodium complex as a catalyst for the selective hydrogenation of substituted aryl and heteroaryl boronate esters to cis-substituted borylated cycloalkanes.IMes/ruthenium complex (Cp*Ru(IMes)Cl)(Cp* =η5-C5Me3) as a catalyst for olefin ring closing metathesis reaction. IMes is also used as an ancillary ligand in Pd-catalyzed Suzuki-Miyaura cross-coupling reaction between aryl chlorides or aryl triflates and arylboronic acids.

InChI:InChI=1/C21H24N2/c1-14-9-16(3)20(17(4)10-14)22-7-8-23(13-22)21-18(5)11-15(2)12-19(21)6/h7-12H,1-6H3

Upstream product

• 109-99-9 tetrahydrofuran 
• 1130280-40-8 1,3-bis(2,4,6-trimethylphenyl)imidazole hydrochloride 
• 201230-82-2 carbon monoxide 
• 141556-45-8 1,3-bis(mesityl)imidazolium chloride 
• 19824-59-0 pentakis(dimethylamido)tantalum 
• 1382354-86-0 1,3-bis(2,4,6-trimethylphenyl)imidazolium tetraphenylborate 

Downstream Products

• 797056-39-4 (1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene)trifluoroborane 
• 311311-61-2 In⁽²⁾H₃(C₃H₂N₂(C₉H₁₁)2) 
• 256238-49-0 1,3-dimesitylimidazol-2-ylidene-dimethylcadmium 
• 797056-38-3 (1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene)borane 
• 1276122-09-8 C₃H₂N₂(C₆H₂(CH₃)3)BH₃(C₆H₂(CH₃)2CH₂BH₃)^(1-)*Li⁽¹⁺⁾=[C₃H₂N₂(C₆H₂(CH₃)3)BH₃(C₆H₂(CH₃)2CH₂BH₃)]Li 

Relevant articles and documents

Dialkylgallium Alkoxides Stabilized with N-Heterocyclic Carbenes: Opportunities and Limitations for the Controlled and Stereoselective Polymerization of rac-Lactide

The structure of a series of Me2GaOR(NHC) complexes with N-heterocyclic carbenes (1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (SIMes) and 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes)) have been characterized using spectroscopic and X-ray techniques and discussed in view of their reactivity in the polymerization of rac-lactide (rac-LA). Both structure studies and density functional theory (DFT) calculations show the significant influence of NHC and OR on the structure of investigated complexes and has indicated that the Ga-CNHC bond (32.6-39.6 kcal mol-1) is strong enough to form stable Me2GaOR(NHC) complexes in the form of monomeric species. The reactivity of Me2Ga((S)-OCH(Me)CO2Me)(SIMes) (1) and Me2Ga((S)-OCH(Me)CO2Me)(IMes) (5) toward Lewis acids such as CO2 and GaMe3 has resulted in breaking of the Ga-CNHC bond with the formation of (NHC)CO2 and Me3Ga(NHC) (8 and 10) and [Me2Ga(μ-(S)-OCH(Me)CO2Me)]2. Different results have been obtained for l,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene (SIPr), which coordinates more weakly to gallium, as demonstrated by the Ga-CNHC bond strength for model Me3GaSIMes, Me3GaIMes (8), and Me3GaSIPr (10) adducts. The reaction of SIPr with [Me2Ga(μ-OR)]2 has not allowed for the breaking of Ga2O2 bridges and the formation of monomeric Me2GaOR(SIPr) complexes, contrary to SIMes and IMes. In the case of the reaction with [Me2Ga(μ-(S)-OCH(Me)CO2Me)]2, the ionic compound [Me2Ga(OCH(Me)CO2)]-[SIPrH]+ (9) has been isolated. The investigated Me2GaOR(NHC) complexes are highly active and stereoselective in the ring-opening polymerization of rac-lactide from -20 C to room temperature, due to the insertion of rac-LA exclusively into the Ga-Oalkoxide bond, leading to isotactically enriched polylactide (PLA) (Pm = 0.65-0.78). It has been shown that the polymerization of lactide at low temperature is influenced by the chelate interaction of (S)-OCH(Me)CO2Me or (OCH(Me)C(O))2OR resulting from the primary insertion of rac-LA into the Ga-Oalkoxide bond, with the Ga center, which can be responsible for the low control over the molecular weight of the obtained PLA. The latter effect can be eliminated by the initial synthesis of Me2Ga((PLA)nOR)(NHC) with short PLA chains, which allows for controlled polymerization. Although the adverse chelate effect can be also eliminated by the polymerization of rac-LA at room temperature, the stereoselectivity of rac-LA polymerization is strongly affected by transesterification reactions. Out of investigated Me2GaOR(SIMes) and Me2GaOR(IMes) complexes, only the latter allowed for the immortal ring opening polymerization of rac-LA in the presence of iPrOH (Figure Presented).

Synthesis of Stable Pentacoordinate Silicon(IV)-NHC Adducts: An Entry to Anionic N-Heterocyclic Carbene Ligands

This work features the previously undescribed interactions of Martin's spirosilane with different types of N-heterocyclic carbenes (NHCs). The level of interaction proved to be strongly dependent on the size of the Lewis base and could vary from the formation of isolable classical Lewis adducts to abnormal Lewis adducts, as evidenced by X-ray diffraction structure analyses and NMR studies. It has been found that abnormal adducts could be used as precursors for the synthesis of anionic NHCs bearing a weakly coordinating siliconate component. Complexation of these new types of carbenes with gold(I) and copper(I) has been efficiently accomplished. DFT calculations performed on the siliconate-based anionic NHC ligands revealed a high-lying HOMO and therefore a strong σ-donor character.

Mixture of Azolium Tetraphenylborate with Isopropylthioxanthone: A New Class of N-Heterocyclic Carbene (NHC) Photogenerator for Polyurethane, Polyester, and ROMP Polymers Synthesis

In the search of smarter routes to control the conditions of N-heterocyclic carbene (NHCs) formation, a two-component air-stable NHC photogenerating system is reported. It relies on the irradiation at 365 nm of a mixture of 2-isopropylthioxanthone (ITX) w

Application of the Redox-Transmetalation Procedure to Access Divalent Lanthanide and Alkaline-Earth NHC Complexes**

Divalent lanthanide and alkaline-earth complexes supported by N-heterocyclic carbene (NHC) ligands have been accessed by redox-transmetalation between air-stable NHC-AgI complexes and the corresponding metals. By using the small ligand 1,3-dimethylimidazol-2-ylidene (IMe), two series of isostructural complexes were obtained: the tetra-NHC complexes [LnI2(IMe)4] (Ln=Eu and Sm) and the bis-NHC complexes [MI2(IMe)2(THF)2] (M=Yb, Ca and Sr). In the former, distortions in the NHC coordination were found to originate from intermolecular repulsions in the solid state. Application of the redox-transmetalation strategy with the bulkier 1,3-dimesitylimidazol-2-ylidene (IMes) ligand yielded [SrI2(IMes)(THF)3], while using a similar procedure with Ca metal led to [CaI2(THF)4] and uncoordinated IMes. DFT calculations were performed to rationalise the selective formation of the bis-NHC adduct in [SrI2(IMe)2(THF)2] and the tetra-NHC adduct in [SmI2(IMe)4]. Since the results in the gas phase point towards preferential formation of the tetra-NHC complexes for both metal centres, the differences between both arrangements are a result of solid-state effects such as slightly different packing forces.

Erratum: Synthesis of organic super-electron-donors by reaction of nitrous oxide with n-heterocyclic olefins (Journal of the American Chemical Society (2019) 141:43 (17112?17116) DOI: 10.1021/jacs.9b10660)

We realized that the legend of Figure S20 in the Supporting Information contains mistakes. The UV-vis spectrum of 5a was recorded at a lower concentration than indicated (0.023 mM instead of 0.06 mM), and the solvent used for the measurements was DMSO and not THF. The conclusions are not affected by this error. The Supporting Information has been corrected and is available.