Highly-functionalized arene synthesis based on palladium on carbon-catalyzed aqueous dehydrogenation of cyclohexadienes and cyclohexenes
Transition metal-catalyzed dehydrogenation is a clean oxidation method requiring no additional oxidants. We have accomplished a heterogeneous Pd/C-catalyzed aqueous dehydrogenation of 1,4-cyclohexadienes and cyclohexenes to give the corresponding highly-functionalized arenes. Furthermore, various arenes could be efficiently constructed in a one-pot manner via a Diels-Alder reaction and the following dehydrogenation.
A stable β-silyl carbocation with allyl conjugation
Phenyl group replaced by a double bond yielding a stable β-silyl carbocation was studied. Two systems were examined in which positive charge could be stabilized by one phenyl and one double bond or two double bonds. The carbocation was found to be stable at room temperature with tetrakis(pentafluorophenyl)borate as the anion benzene as the solvents. The range of β-silyl carbocations observed under stable ion conditions was relatively circumscribed.
Lambert, Joseph B.,Liu, Chunqing,Kouliev, Timur
p. 667 - 671
(2007/10/03)
Synthesis of Isomerically Pure (E)- and (Z)-1,3-Disubstituted 1,3-Dienes
The (E)-dienes 1a - p were prepared in >98percent purity by dehydrative decarboxylation of the corresponding 4,5-unsaturated 3-hydroxycarboxylic acids 3 with dimethylformamide dimethylacetal (11).The (Z)-isomers 6a - m were obtained by stereouncontrolled
Mulzer, Johann,Bruentrup, Gisela,Kuehl, Uwe,Hartz, Georg
p. 3453 - 3469
(2007/10/02)
More Articles about upstream products of 21035-05-2