173035-11-5

Basic information

• Product Name: 1,3-Dimesitylimidazolidin-2-ylidene
• Synonyms: 1,3-Dimesitylimidazolidin-2-ylidene;1,3-Bis(2,4,6-trimethylphenyl)-4,5- dihydroimidazol-2-ylidene, min. 98%;1,3-Bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene;1,3-Bis(2,4,6-trimethyphenyl)4,5- dihydroimidazol-2-ylidene;1,3-Bis(2,4,6-trimethylphenyl)imidazolidin-2-ylidene;IMesH2;SIMes;1,3-Bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene,98%
• CAS NO: 173035-11-5
• Molecular Formula: C₂₁H₂₆N₂
• Molecular Weight: 306.45
• Product Categories: N-heterocyclic carbene
• Mol File: 173035-11-5.mol

Chemical Properties

• Melting Point: 85-100°C
• Appearance: pale yellow/Powder
• Storage Temp.: ?20°C
• Sensitive: air sensitive, moisture sensitiv
• CAS DataBase Reference: 1,3-Dimesitylimidazolidin-2-ylidene(CAS DataBase Reference)
• NIST Chemistry Reference: 1,3-Dimesitylimidazolidin-2-ylidene(173035-11-5)
• EPA Substance Registry System: 1,3-Dimesitylimidazolidin-2-ylidene(173035-11-5)

Safety Data

• WGK Germany: 3
• Hazardous Substances Data: 173035-11-5(Hazardous Substances Data)

Usage

Reactions

Ligand for copper-catalyzed regioselective formation of tri- and tetrasubstituted vinylboronates in air. Ligand for highly active ruthenium catalyst for hydrogenation of olefins. Electrophilic phosphonium cations component for ketone catalytic hydrodeoxygenation/hydrosilylation. Used in selective activation of fluoroalkenes to produce N-heterocyclic fluoroalkenes and polyfluoroalkenyl imidazolium salts.

Upstream product

• 1130280-38-4 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene hydrochloride 
• 258278-23-8 N¹,N²-dimesitylethane-1,2-diaminium chloride 
• 88-05-1 2,4,6-trimethylaniline 
• 56222-36-7 N,N'-bis(2,4,6-trimethylphenyl)ethanediimine 
• 134030-21-0 N,N'-dimesityl-1,2-ethanediamine 
• 782479-45-2 1,3-di(2,4,6-trimethylphenyl)-2-(pentafluorophenyl)-2,4,5-trihydroimidazole 
• 260054-47-5 1,3-bis(2,4,6-trimethylphenyl)-2-(trichloromethyl)imidazolidine 
• 173035-10-4 1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazolium chloride 
• 141556-45-8 1,3-bis(mesityl)imidazolium chloride 
• 75105-48-5 N,N'-dimesitylformamidine 

Downstream Products

• 1443153-95-4 C₂₁H₂₆N₄O 
• 1442058-15-2 C₃₉H₄₈B₂Br₂N₂ 
• 1442058-45-8 C₂₉H₄₄B₂Cl₂N₂ 
• 1418182-96-3 C₃₇H₃₆CrN₂O₆ 
• 1416320-26-7 2-(methoxymethylidene)-1,3-bis(2,4,6-trimethylphenyl)imidazolidine 
• 1416319-93-1 [1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene]phenylmethanol 
• 1172134-50-7 9-bora-9-(1,3-dimesityl-4,5-dihydroimidazol-2-ylidene)anthracene oxygen adduct 
• 1172134-49-4 9-boraanthracene-H₂IMes 

Relevant articles and documents

Organic spirocyclic initiators for the ring-expansion polymerization of β-lactones

We report spirocyclic imidazolidines derived from N-heterocyclic carbenes and β-lactones. These spirocycles are initiators for the zwitterionic ring-expansion polymerization of β-lactones to generate cyclic polyesters of well-defined molecular weight. The

Selective Activation of Fluoroalkenes with N-Heterocyclic Carbenes: Synthesis of N-Heterocyclic Fluoroalkenes and Polyfluoroalkenyl Imidazolium Salts

Selective reactions between nucleophilic N,N′-diaryl-heterocyclic carbenes (NHCs) and electrophilic fluorinated alkenes afford NHC fluoroalkenes in high yields. These stable compounds undergo efficient and selective fluoride abstraction with Lewis acids to give polyfluoroalkenyl imidazolium salts. These salts react at Cβ with pyrrolidine to give ammonium fluoride-substituted salts, which give rise to conjugated imidazolium-enamine salts through loss of HF. Alternatively, reaction with 4-(dimethylamino)-pyridine provides a Cα-pyridinium-substituted NHC fluoroalkene. These compounds were studied using multinuclear NMR spectroscopy, mass spectrometry, and X-ray crystallography. Insight into their electronic structure and reactivity was gained through the use of DFT calculations. The unusual suspects: N,N′-Diaryl-heterocyclic carbenes react with fluorinated alkenes to afford N-heterocyclic fluoroalkenes in high yields. Efficient and selective fluoride abstraction with Lewis acids affords the first examples of polyfluoralkenyl imidazolium salts. These salts react with pyrrolidine and DMAP through different pathways to provide unique compounds.

Strong ligand accelerated catalysis by an Arduengo-type carbene in copper-catalysed conjugate addition

The addition of stabilised carbene ligand:CNMesCH2CH2NMes (Mes=2,4,6-Me3C6H2) results in a dramatic rate increase in the Cu(OTf)2-catalysed conjugate addition of ZnEt2 to enones (OTf=triflate anion).

Organic Redox Systems Based on Pyridinium-Carbene Hybrids

New redox systems with three oxidation states are highly sought-after, for example, for redox-flow battery applications, selective reducing agents, or organic electronics. Herein, we describe a straightforward and modular synthesis of a new class of such

Copper-NHC-Mediated Semihydrogenation and Hydroboration of Alkynes: Enhanced Catalytic Activity Using Ring-Expanded Carbenes

A series of two-coordinate copper tert-butoxide complexes bearing five-, six-, and seven-membered ring N-heterocyclic carbenes, prepared by protonolysis of (NHC)CuMes with tBuOH, have been used as catalytic precursors in the semihydrogenation of alkynes with silanes/tBuOH and the hydroboration of alkynes with HBPin. Both processes proceed with high regioselectivity and show enhancements with six- and seven-membered ring carbenes.

Pyrylenes: A New Class of Tunable, Redox-Switchable, Photoexcitable Pyrylium-Carbene Hybrids with Three Stable Redox-States

A new synthetic and modular access to a large family of redox-switchable molecules based upon the combination of pyrylium salts and carbenes is presented. The redox-properties of this new molecule class correlate very well with the π-accepting properties of the corresponding carbenes. While the pyrylium moiety acts as a chromophore, the carbene moiety can tune the redox-properties and stabilize the corresponding radicals. This leads to the isolation of the first monomeric pyranyl-radical in the solid-state. The three stable oxidation states could be cleanly accessed by chemical oxidation, characterized by NMR, EPR, UV-vis, and X-ray diffraction and supported by (TD)-DFT-calculations. The new hybrid class can be utilized as an electrochemically triggered switch and as a powerful photoexcited reductant. Importantly, the pyrylenes can be used as novel photocatalysts for the reductive activation of aryl halides and sulfonamides by consecutive visible light induced electron transfer processes.

A closer look at the reactivity between N-heterocyclic carbenes and fluoroalkenes

The fundamental reactivity leading to N-heterocyclic fluoroalkene adducts is explored in detail, featuring a total of 15 N-heterocyclic carbenes (NHCs) with various electronic and steric environments. The activity of these carbenes towards tetrafluoroethylene (TFE), hexafluoropropene (HFP), trifluoroethylene (HTFE) and vinylidene fluoride (VDF) is assessed in THF and toluene. Attempts were made to correlate the observed reactivity with electronic (Tolman Electronic Parameters) and steric (% buried volume) parameters unique to each NHC, but a trend has yet to be fully determined. However, the unique steric constraints of a cyclic (alkyl)(amino)carbene (CAAC) were shown to modify the initial point of nucleophilic attack on HTFE, providing selective transformation to a different adduct than has been observed to date with all reactions involving this fluoroalkene.

Expanded ring diaminocarbene palladium complexes: Synthesis, structure, and Suzuki-Miyaura cross-coupling of heteroaryl chlorides in water

A series of new 6- and 7-membered N-heterocyclic carbene (NHC) complexes of palladium (NHC)Pd(cinn)Cl (cinn = cinnamyl = 3-phenylallyl) were synthesized and characterized structurally in the solid state. The influence of ring size (5, 6 or 7) and bulkiness of N-aryl substituents (Mes = 2,4,6-trimethylphenyl, or Dipp = 2,6-diisopropylphenyl) in carbenes on palladium catalysed Suzuki-Miyaura cross-coupling was revealed. Due to the unique stereoelectronic properties of expanded ring NHCs, a versatile, highly efficient green protocol of coupling of heteroaromatic chlorides and bromides with boronic acids has been developed. High quantitative yields of biaryls were achieved with water as solvent, under air, using low catalyst and phase transfer agent loadings, and with mild and environmentally benign base NaHCO3. The Royal Society of Chemistry 2013.

Selective reduction of esters to aldehydes under the catalysis of well-defined NHC-iron complexes

On a direct course to the aldehyde: Hydrosilylation catalyzed by a well-defined N-heterocyclic-carbene-iron complex under UV irradiation enabled the selective reduction of esters to aldehydes (see scheme; Bn=benzyl, Mes=mesityl). The low catalyst loading and very mild reaction conditions make this chemoselective transformation a promising alternative to the reduction of esters with diisobutylaluminum hydride. Copyright

The first facile stereoselectivity switch in the polymerization of rac-lactide - From heteroselective to isoselective dialkylgallium alkoxides with the help of N-heterocyclic carbenes

The reaction of N-heterocyclic carbene (NHC) with dimeric dialkylgallium alkoxides, acting as nonselective or heteroselective catalysts in the polymerization of rac-LA, leads to highly active and isoselective monomeric Me2Ga(NHC)OR catalysts, resulting for the first time in the facile switch of stereoselectivity. The Royal Society of Chemistry 2012.