Search results
Results From The WOW.Com Content Network
The process, which is catalyzed by platinum supported by aluminium oxide, is exemplified in the conversion methylcyclohexane (a naphthene) into toluene (an aromatic). [2] Dehydrocyclization converts paraffins (acyclic hydrocarbons) into aromatics. [3] A related aromatization process includes dehydroisomerization of methylcyclopentane to benzene:
Cyclopentadiene is a highly reactive diene in the Diels–Alder reaction because minimal distortion of the diene is required to achieve the envelope geometry of the transition state compared to other dienes. [11] Famously, cyclopentadiene dimerizes. The conversion occurs in hours at room temperature, but the monomer can be stored for days at ...
The spontaneous dimerization of neat cyclopentadiene at room temperature to form dicyclopentadiene proceeds to around 50% conversion over 24 hours and yields the endo isomer in better than 99:1 ratio as the kinetically favored product (about 150:1 endo:exo at 80 °C). [6] However, prolonged heating results in isomerization to the exo isomer.
There is a notable rate enhancement when certain Diels–Alder reactions are carried out in polar organic solvents such as dimethylformamide and ethylene glycol, [13] and even in water. [14] The reaction of cyclopentadiene and butenone for example is 700 times faster in water relative to 2,2,4-trimethylpentane as solvent. [14]
Cp 2 Fe 2 (CO) 4 was first prepared in 1955 at Harvard by Geoffrey Wilkinson using the same method employed today: the reaction of iron pentacarbonyl and dicyclopentadiene. [7] [8] 2 Fe(CO) 5 + C 10 H 12 → (η 5-C 5 H 5) 2 Fe 2 (CO) 4 + 6 CO + H 2. In this preparation, dicyclopentadiene cracks to give cyclopentadiene, which reacts with Fe(CO ...
In organic chemistry, pentadiene is any hydrocarbon with an open chain of five carbons, connected by two single bonds and two double bonds. All those compounds have the same molecular formula C 5 H 8. The inventory of pentadienes include: 1,2-pentadiene, or ethyl allene, H 2 C=C=CH−CH 2 −CH 3. [1]
More recently, trifluoromethylation of diazonium salts has been developed and is referred to as a 'Sandmeyer-type' reaction. Diazonium salts also react with boronates, iodide, thiols, water, hypophosphorous acid and others, [6] and fluorination can be carried out using tetrafluoroborate anions (Balz–Schiemann reaction). However, since these ...
Hexachlorocyclopentadiene is prepared by chlorination of cyclopentadiene to give 1,1,2,3,4,5-octachlorocyclopentane, which in a second step undergoes dehydrochlorination: [3] The first procedure uses alkaline hypochlorite and after fractional distillation has a yield of about 75%, the other 25% consists of lower chlorinated cyclopentadienes. [4]