Palladium-catalyzed regioselective C-H bond arylations at the C3 position of ortho-substituted fluorobenzenes.

The influence of an ortho-substituent on fluorobenzene derivatives for palladium-catalyzed C-H bond arylation has been explored. In the presence of 2-bromo, 2-chloro and 2-methoxy substituents, the reaction proceeds nicely using a diphosphine-palladium catalyst and potassium acetate/dimethylacetamide (PivOK/DMA) as the catalytic system. In all cases, a regioselective arylation at the other ortho-position to the fluorine atom (C3) was observed.

Palladium-Catalyzed C-H Bond Functionalization of 6,6-Diphenylfulvenes: An Easier Access to C1-Arylated and C1,C4-Diarylated Fulvenes.

Conditions allowing the palladium-catalyzed regioselective direct arylation of fulvene derivatives are reported. The nature of the aryl source exhibits an important influence on the yield. The reaction of fulvenes with aryl bromides gave poor yields, whereas the use of benzenesulfonyl chlorides gave rise to fulvenes arylated at C1- and C4-positions on the 5-membered ring in good yields.

Regiocontroled Pd-catalysed C5-arylation of 3-substituted thiophene derivatives using a bromo-substituent as blocking group.

The use of a bromo-substituent as blocking group at the C2-position of 3-substituted thiophenes allows the regioselective introduction of aryl substituents at C5-position via Pd-catalysed direct arylation. With 1 mol % of a phosphine-free Pd catalyst, KOAc as the base and DMA as the solvent and various electron-deficient aryl bromides as aryl sources, C5-(hetero)arylated thiophenes were synthesized in moderate to high yields, without cleavage of the thienyl C-Br bond. Moreover, sequential direct thienyl C5-arylation followed by Pd-catalysed direct arylation or Suzuki coupling at the C2-position allows to prepare 2,5-di(hetero)arylated thiophenes bearing two different (hetero)aryl units in only two steps.

Palladium-catalyzed direct desulfitative C2 arylations of 3-halo-N-protected indoles using (hetero)arenesulfonyl chlorides.

The direct arylation of N-protected 3-haloindole derivatives with benzenesulfonyl chlorides as coupling partners using 5 mol% of bis(acetonitrile)dichloropalladium(ii) catalyst and lithium carbonate as a base in 1,4-dioxane was investigated. We demonstrated that both iodo and chloro substituents at the indolyl C3 position act as temporary blocking groups allowing the formation of 2-arylindoles through a direct desulfitative arylation, followed by in situ dehalogenation. While, from 3-bromoindole derivatives, 2-aryl-3-bromoindoles were obtained without debromination, and could be converted into 2,3-diarylindoles through a second palladium coupling.

Eco-friendly solvents for palladium-catalyzed desulfitative C-H bond arylation of heteroarenes.

Herein, we report the Pd-catalyzed regioselective direct arylation of heteroarenes in which benzenesulfonyl chlorides are used as coupling partners through a desulfitative cross-coupling that can be performed in diethyl carbonate (DEC) or cyclopentyl methyl ether (CPME) as green and renewable solvents or even in neat conditions instead of dioxane or dimethylacetamide (DMA). Under these solvent conditions, the reaction proceeds with a wide range of heteroarenes. C2- or C5-arylated products were obtained with furan and pyrrole derivatives.

New chiral 4-substituted 2-cyanoethyl-oxazolines: synthesis and assessment of some biological activities.

This paper describes the synthesis of new enantiomerically pure 2-cyanoethyl-oxazolines in one step starting from a wide range of amino alcohols and 4-ethoxy-4-iminobutanenitrile with high to good yields (73-96%) via an appropriate procedure which can be used for a selective synthesis of mono-oxazolines. A simple operation as well as a practical separation is additional eco-friendly attributes of this method. All the synthesized compounds were identified and characterized with their physicochemical features and their spectral data ((1)H NMR, (13)C NMR and TOFMS ES(+)).

3-Amino-4-(1,3-benzoxazol-2-yl)-5-(cyclo-hexyl-amino)-thio-phene-2-carbo-nitrile.

In the title compound, C18H18N4OS, the cyclo-hexyl ring adopts a chair conformation. The other rings of this compound lie almost in the same plane, with a mean deviation of 0.03 (2) Å from the least-squares plane defined by the 14 constituent atoms.