Competing amination and C–H arylation pathways in Pd/xantphos-catalyzed transformations of binaphthyl triflates: switchable routes to chiral amines and helicene derivatives
作者:Aaron A. Ruch、Sachin Handa、Fanji Kong、Vladimir N. Nesterov、Dale R. Pahls、Thomas R. Cundari、LeGrande M. Slaughter
DOI:10.1039/c6ob01102k
日期:——
intramolecular Pd-catalyzed C–H arylation was observed as a competing side reaction under some conditions. By adjusting the solvent and quantity of the amine, the reaction was optimized to favor either the amination or the C–H arylation pathway, affording two distinct and potentially useful sets of products. The amines represent tunable chiral ligand precursors, while the C–H arylation pathway affords a series
2-diarylbenzenes induce intramolecular C–C bond formation. The substrates studied were prepared by the stepwise Suzuki–Miyaura coupling reaction that introduced 2-naphthyl, 2-anthranyl, and 2-pyrenyl groups on the ortho-positions of benzene. The subsequent oxidation reaction with FeCl3 induced an oxidative C–C bond formation reaction in the interior regions of the molecules. In marked contrast to our previous
Thermal Cyclodehydrogenations To Form 6-Membered Rings: Cyclizations of [5]Helicenes
作者:Xiang Xue、Lawrence T. Scott
DOI:10.1021/ol7015516
日期:2007.9.1
Flash vacuum pyrolysis (FVP) of [5]helicene induces a thermal cyclodehydrogenation to form benzo[ghi]perylene. Evidence is presented that supports an electrocyclization-rearomatization mechanism and is inconsistent with mechanistic alternatives involving the intermediacy of aryl radicals or carbenes in the helicene fjord region.
Tinnemans,A.H.A. et al., Recueil des Travaux Chimiques des Pays-Bas, 1975, vol. 94, p. 239 - 243
作者:Tinnemans,A.H.A. et al.
DOI:——
日期:——
Aromatic Metamorphosis of Dibenzofurans into Triphenylenes Starting with Nickel-Catalyzed Ring-Opening C–O Arylation
A new class of aromaticmetamorphosis has been developed in which dibenzofurans were converted into triphenylenes. This transformation is composed of three successive operations: (1) nickel-catalyzed ring-opening C–O bond arylation with arylmagnesium bromides, (2) trifluoromethanesulfonylation (triflation) of the resulting hydroxy moiety with Tf2O, and (3) palladium-catalyzed or photoinduced ring closure