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Downstream Products

• 3419-73-6 1-phenyl-4-tert-butylcyclohexene 

Relevant academic research and scientific papers

Solvolysis of cyclohexenyliodonium salt, a new precursor for the vinyl cation: Remarkable nucleofugality of the phenyliodonio group and evidence for internal return from an intimate ion-molecule pair

Solvolysis of (4-tert-butyl-1-cyclohexenyl)aryliodonium tetrafluoroborates was examined in alcohol and aqueous solutions at 25-70 °C. Phenyliodonio group was found to be a remarkably good nucleofuge with a leaving ability about 106 times greater than triflate. In addition to the expected solvolysis products, 1-alkoxycyclohexene and/or cyclohexanone and iodobenzene, the internal return products, (4-tert-butyl-1-cyclohexenyl)iodobenzenes, were obtained in yields of 13-15% in methanol and aqueous solutions and of 30-40% in trifluoroethanol. The ortho derivative is the predominant isomer of these products, and this isomeric distribution is taken as indicating that the : return is occurring from the intimate ion-molecule pair. The formation of a free-radical product, 4-ferf-butylcyclohexene (1%), was detected during the solvolysis in the presence of 1,4-cyclohexadiene or in 2-propanol, while a considerable amount of the cationic rearrangement product, cyclopentyl methyl ketone, was obtained in the solvolysis of (2-methyl-1-cyclohexenyl)phenyliodonium tetrafluoroborate. A proposed mechanism involves mainly heterolysis to give the cyclohexenyl cation-iodobenzene pair with accompanying single electron transfer (or with competing homolysis) to lead to a free radical intermediate.

Reactions of cyclohexenyl iodonium tetrafluoroborate with bromide ion: Retardation due to the formation of λ3-bromoiodane

The reaction of 4-tert-butylcyclohex-1-enyl(phenyl)iodonium tetrafluoroborate (1a) and the 4-chlorophenyl derivative (1b) with bromide ion was examined in methanol, acetonitrile, and chloroform. Products include those derived from the intermediate cyclohexenyl cation as well as 1-bromocyclohexene. Kinetic measurements show that the reaction of 1 is strongly retarded by the added bromide. The curved dependence of the observed rate constant on the bromide concentration is typical of a pre-equilibrium formation of the intermediate adduct with a fast bromide-independent reaction (solvolysis of the iodonium ion). The formation of the adduct, λ3-bromoiodane, was also confirmed by the UV spectral change. The relative reactivity of the iodonium ion and λ3-bromoiodane is evaluated to be on the order of 102. The bromide substitution product forms both via the SN1 reaction of the free iodonium ion and via the ligand coupling of the iodane.

Thermal decomposition of alkenyliodonium tetrafluoroborates: A novel route to fluoroalkenes

Alkenyl(phenyl)iodonium tetrafluoroborates dissolved in chloroform, or in the solid state, decompose thermally at 60°C to yield fluoroalkenes and iodobenzene as major products via an S(N)1- or S(N)2-type reaction within the ion pair of the substrates. (C) 2000 Elsevier Science Ltd.