7167-28-4

Upstream product

• 542-92-7 cyclopenta-1,3-diene 
• 80-62-6 methacrylic acid methyl ester 
• 769-85-7 methyl exo-5-norbornene-2-carboxylate 
• 74-88-4 methyl iodide 
• 6203-08-3 methyl 5-norbornene-2-carboxylate 
• 934-30-5 exo-5-norbornene-2-carboxylic acid 
• 77-73-6 bi(cyclopentadiene) 

Relevant academic research and scientific papers

Total Synthesis of (±)-2-Isocyanoallopupukeanane

2-Isocyanoallopupukeanane (4) has been obtained in racemic form from methyl 2-exo-methylbicyclo-[2.2.1]hept-5-ene-2-endo-carboxylate via dibromocarbene addition, SN2′ displacement, chain extension, and elaboration of the unsaturated ketone 12c which underwent an intramolecular hetero-Diels-Alder reaction to afford 13 containing all the skeletal carbon atoms. The dihydropyran unit was cleaved by ozonolysis to give the tricarbocyclic intermediate which required seven more steps to complete the synthesis.

Origin of reversal of stereoselectivity for [4+2] cycloaddition reaction between cyclopentadiene and methyl methacrylate in the presence of the chloroloaluminate ionic liquid (1-ethyl-3-methyl-imidazolium chloride): In silico studies

The origin of stereoselectivity for [4+2] cycloaddition reaction of methyl methacrylate with cyclopentadiene was investigated with the B3LYP-D3(BJ)/6- 31+G(d)//B3LYP/6-31+G(d) level of theory in the presence of the ionic liquid 1-ethyl-3-methyl-imidazolium chloride (EMI+Cl-) and its acidic chloroaluminate melt, 1-ethyl-3-methyl-imidazolium heptachlorodialuminate (EMI+Al2Cl7-). The reaction of methyl methacrylate with cyclopentadiene was examined in the gas phase to rationalize the effect of the ionic liquid ion pairs EMI+Cl - and EMI+Al2Cl7-. The DFT calculated results were found to be in good agreement with the experimentally observed results. The much-discussed hydrogen bonding effect of the imidazolium cation with the dienophile is less important to govern the stereoselectivity for the cycloaddition reaction. The atoms in molecules theory was used to examine the role of hydrogen bonding between the EMI+ cation and methyl methacrylate in the transition state geometries. The calculated activation barriers with the M062X/6-31+G(d)//B3LYP/6-31+G(d) and MP2/6-311+G(d,p)//B3LYP/6-31+G(d) levels of theory also predict the similar exo/endo-stereoselectivity trend for the cycloaddition reactions.

Salt effect on the endo/exo ratio of the reaction of cyclopentadiene with methyl methacrylate

The salt effect on the stereoselectivity of the reaction of cyclopentadiene with methyl methacrylate has been investigated. CaCl2, Na2SO4, KCl and LiCl enhance the endo/exo ratios, while guanidinium chloride (GnCl) and LiClO4 decrease them. The results are supported by independent calculations of salting-out and in coefficients.

Stereoselective synthesis of 2-isocyanoallopupukeanane

(matrix presented) A stereoselective synthesis of 2-isocyanoallopupukeanane (3) in ca, 5% overall yield features an intramolecular Diels-Alder reaction to establish a bridged cyclopentane ring to the existing bicyclo[3.2.1]octane unit.

Synthesis of saturated bicyclic diesters

Bicyclic saturated diesters were synthesized by the catalytic addition of monobasic saturated acids to unsaturated bicyclic esters. A possible mechanism of the reaction was proposed.

Hydrogen-bond-rich ionic liquids as effective organocatalysts for Diels-Alder reactions

The synthesis and characterisation of new hydrogen-bond-rich ionic liquids and studies of their catalytic performance in Diels-Alder reactions are described. d-Glucose and chloroalcohols were used as the raw materials and as the sources of hydroxyl groups for the synthesis of ionic-liquid cations, whereas weakly coordinating bis(trifluoromethylsulfonyl)imide was used as the anion. The new ionic liquids were analysed by 1H and 13C NMR spectroscopy and by ESI-MS experiments, which confirmed their structures. In addition, the thermal data of the studied ionic liquids measured by differential scanning calorimetry and thermogravimetric analysis showed that these compounds tend to form a glass at temperatures in the range of -29°C to -16°C and are thermally stable from ambient temperature to at least 430°C, most likely because of the presence of bis(trifluoromethylsulfonyl) imide anions. The performance of the ionic liquids in the model reaction of cyclopentadiene with diethyl maleate or methyl acrylate was investigated. The studied ionic liquids showed high activity even when present in catalytic amounts (4 mol% with respect to the dienophile). An increase in the number of hydroxyl groups present in the ionic liquid structure resulted in higher reaction rates. This journal is the Partner Organisations 2014.

Converting exo-Selective Diels-Alder Reaction to endo-Selective in Chloroloaluminate Ionic Liquids

The endo:exo ratio of 0.35:1 for the reaction of cyclopentadiene with methyl methacrylate observed in organic solvents can be converted to 3:1 in chloroaluminate ionic liquids with their effective reuse in Diels-Alder reactions.

Nanoporous solid acid catalyst for the Diels-Alder reaction of 1,3-dienes with acrylates

Nanoporous aluminosilicate, Al-HMS with a high aluminum content, strong acidity, and nanoporosity was found to catalyze the Diels-Alder reaction of 1,3-dienes with methacrylate and acrylate, and turned out to be a green alternative to homogeneous acid catalysts.

Trimethylsilyl bis(trifluoromethanesulfonyl)imide as a tolerant and environmentally benign Lewis acid catalyst of the Diels-Alder reaction

N-trimethylsilyl bis(trifluoromethanesulfonyl)imide (TMSNTf2) was readily prepared in situ by protodesilylation of trimethylsilane, allyl- or phenyltrimethylsilane with bis(trifluoromethylsulfonyl)imide. NMR studies showed that TMSNTf2 was much more effective than TMSOTf in complexing the carbonyl group of trans-methylcrotonate. As a result, TMSNTf2 was found to be superior to TMSOTf as a catalyst for the Diels-Alder reaction of α,β-unsaturated esters with a wide variety of dienes. In contrast to many metal derived Lewis acids, TMSNTf2 was found tolerant of many sensitive functional groups present in the diene partner.

Catalysis by solid acid: Selective Diels-Alder reactions are promoted by mesoporous aluminosilicate with zinc ions and nanometer honeycomb openings

Zinc ion-exchanged mesoporous aluminosilicate has been designed specifically to accelerate the Diels-Alder reaction between cyclopentadiene and poor dienophiles such as methyl acrylate and methyl methacrylate. Catalysis on this aluminosilicate is more effective than on a K10-based solid acid catalyst.