- A meta-Xylylene by Bamford-Stevens-Reaction of a Fulvene-Ketene-Adduct
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Heating the sodium salt 8 of the tosylhydrazone 4 of 4-isopropyliden-7,7-dimethylbicyclohept-2-en-6-one (3; obtained by the addition of dimethylketene to 6,6-dimethylfulvene (1)), in diglyme at 130 deg C led to the octamethyl-metacyclophane 10 (17 percent).The latter probably was formed by dimerization of the non-Kekule molecule m-xylylene 14, which, in turn, could have arisen via the homofulvene 13 from the carbene 12.A second product in the thermolysis of 8 was the tricycle 9 (9 percent), as a result of an intramolecular insertion of the carbene C-atom in 12 into a methyl C,H-bond.Further products were the azines 11a, 11b (50 percent), of the type known as byproducts in Bamford-Stevens reactions.Heating dry 8 afforded 9 (9 percent) and the two benzene derivatives 15 (9 percent) and 16 (3 percent).The tosylhydrazone 4 could be recovered by reaction of 11a, 11b with p-toluenesulfonohydrazide.
- Stadler, Heinz,Rey, Max,Dreiding, Andre S.
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- A Metal-Free Oxidative Dehydrogenative Diels–Alder Reaction for Selective Functionalization of Alkylbenzenes
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Functionalization of C(sp3)?H bonds under metal-free reaction conditions is a great challenge due to poor bond reactivity. A novel metal-free oxidative dehydrogenative Diels–Alder reaction of alkylbenzene derivatives with alkenes through C(sp3)?H bond functionalization is described. The developed oxidative method provides a straightforward approach to biologically relevant 1,4-phenanthraquinone and isoindole derivatives from readily available starting materials. Furthermore, the synthesis of nitrostyrenes from enylbenzene derivatives by selective C(sp3)?H bond functionalization has been demonstrated.
- Manna, Srimanta,Antonchick, Andrey P.
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supporting information
p. 7825 - 7829
(2017/06/06)
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- METHOD OF DEHYDROGENATING TRIISOPROPYLBENZENE AND DIISOPROPYLBENZENE
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An economical and industrial method for the dehydrogenation of triisopropyl benzene can be provided by carrying out the reaction employing a solid catalyst having an iron compound and potassium compound as major components or an iron compound, potassium compound, and magnesium compound as major components, as a dehydrogenating catalyst for producing diisopropyl isopropenyl benzene, isopropyl diisopropenyl benzene and/or triisopropenyl benzene from triisopropyl benzene. In the dehydrogenation of triisopropyl benzene or diisopropyl benzene, by carrying out an off-and-on reaction in which the above described solid catalyst is employed and with which a regeneration period with steam or oxygen or air is provided, an economical and industrial dehydrogenation method having an extended life of the catalyst can be provided and will have an industrial superiority.
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