3968-91-0

Upstream product

• 56253-64-6 (2-methyl-1-butenyl)-benzene 
• 6921-34-2 benzylmagnesium chloride 
• 766-04-1 benzyllithium 
• 1499-63-4 (2R*,3R*)-3-methyl-4-phenyl-2-butanol 
• 56836-93-2 3-methyl-4-phenylbutan-2-ol 
• 91861-57-3 ((E)-2-Methyl-3-phenyl-allyl)-triphenyl-phosphonium; bromide 
• 3017-68-3 (Z)-2-Bromo-2-butene 
• 100-39-0 benzyl bromide 
• 91861-62-0 (1,2-dimethyl-3-phenyl-2-propenyl)-triphenylphosphonium iodide 
• 74-88-4 methyl iodide 

Relevant academic research and scientific papers

Combining Q2MM modeling and kinetic studies for refinement of the osmium-catalyzed asymmetric dihydroxylation (AD) mnemonic

The interactions between the substrate and the ligand in the Sharpless AD reaction have been examined in detail, using a combination of substrate competition experiments and molecular modeling of transition states. There is a good agreement between comput

Radical ions in photochemistry. 21. The photosensitized (electron transfer) tautomerization of alkenes; the phenyl alkene system

Alkenes, conjugated with a phenyl group, can be converted to nonconjugated tautomers by sensitized (electron transfer) irradiation.For example, irradiation of an acetonitrile solution of the conjugated alkene 1-phenylpropene, the electron accepting photosensitizer 1,4-dicyanobenzene, the cosensitizer biphenyl, and the base 2,4,6-trimethylpiridine gave the nonconjugated tautomer 3-phenylpropene in good yield.Similarly, 2-methyl-1-phenylpropene gave 2-methyl-3-phenylpropene, and 1-phenyl-1-butene gave E- and Z-1-phenyl-2-butene.The reaction also works well with cyclic alkenes.For example, 1-phenylcyclohexene gave 3-phenylcyclohexene, and 1-(phenylmethylene)cyclohexane gave 1-(phenylmethyl)cyclohexene.The proposed mechanism involves the initial formation of the alkene radical cation and the sensitizer radical anion, induced by irradiation of the sensitizer and mediated by the cosensitizer.Deprotonation of the radical cation assisted by the base gives the ambident radical, which is then reduced to the anion by the sensitizer radical anion.Protonation of the ambident anion at the benzylic position completes the sequence.Reprotonation at the original position is an energy wasting step.Tautomerization is driven toward the isomer with the higher oxidation potential, which is, in the cases studied, the less thermodinamically stable isomer.The tautomerization of 2-methyl-1-phenylbutene gave both 2-phenylmethyl-1-butene and 2-methyl-1-phenyl-2-butene (E and Z isomers), while 2,3-dimethyl-1-phenylbutene gave only 3-methyl-2-phenylmethyl-1-butene.In the latter case, steric interaction of the methyls on the isopropyl group prevents effective overlap of the tertiary carbon-hydrogen bond with the singly occupied molecular orbital, thus inhibiting deprotonation from this site.Key words: photosensitized, electron transfer, alkene, tautomerization, radical cation.