A short and efficient synthesis of N-aryl- and N-heteroaryl-N′-(arylalkyl)piperazines

Pd/PTABS: Catalyst for Room Temperature Amination of Heteroarenes

A mild and highly efficient catalytic amination procedure for chloroheteroarenes at ambient temperature using the Pd/PTABS catalytic system is reported. The protocol is selective for the amination of chloroheteroarenes using secondary amines such as piperidine, pyrrolidine, and several others. The exceptional mildness of the developed protocol is beneficial for the synthesis of a crucial Buparlisib intermediate as well as the formal synthesis of Alogliptin in competitive yields.

Amination of heteroaryl chlorides: palladium catalysis or SN Ar in green solvents?

The reaction of heteroaryl chlorides in the pyrimidine, pyrazine and quinazoline series with amines in water in the presence of KF results in a facile SN Ar reaction and N-arylation. The reaction is less satisfactory with pyridines unless an additional electron-withdrawing group is present. The results showed that the transition-metal-free SN Ar reaction not only compares favourably to palladium-catalysed coupling reactions but also operates under environmentally acceptable ("green") conditions in terms of the base and solvent.

Palladium-Catalyzed Coupling of Functionalized Primary and Secondary Amines with Aryl and Heteroaryl Halides: Two Ligands Suffice in Most Cases

We report our studies on the use of two catalyst systems, based on the ligands BrettPhos (1) and RuPhos (2), which provide the widest scope for Pd-catalyzed C-N cross-coupling reactions to date. Often low catalyst loadings and short reaction times can be used with functionalized aryl and heteroaryl coupling partners. The reactions are highly robust and can be set up and performed without the use of a glovebox. These catalysts should find wide application in the synthesis of complex molecules including pharmaceuticals, natural products and functional materials.

Efficient palladium-catalyzed synthesis of 3-aryl-4-indolylmaleimides

Improved palladium catalysts for the Suzuki coupling of 3-bromo-1-methyl-4-(2-methyl-3-indolyl)maleimide have been developed. The coupling of both aryl- and heteroarylboronic acids proceeds smoothly in good to excellent yields at low catalyst loading.

A general copper-catalyzed sulfonylation of arylboronic acids

A general copper-catalyzed method for the sulfonylation of arylboronic acids with sulfinate salts is described. A variety of alkyl-aryl, diaryl, and alkyl-heteroaryl sulfones were synthesized in good yield.

New Synthetic Protocols for the Preparation of Unsymmetrical Bisindoles

Novel unsymmetrical bisindoles were synthesized by a solvent-free C-C bond-formation reaction under mild conditions. Starting from aziridines or hydroxyl precursors, indoles have been used as C-nucleophiles to form new pharmacologically interesting bisindoles via an electrophilic aromatic substitution pathway in good to excellent yields. [reaction: see text]