Diastereoselective Anomeric C(sp)-H Cyclization Towards the Design of New Cyclophane-Braced Glycopeptides.

Here we report a macrocyclization route towards the synthesis of glycophane peptides by a selective C-H arylation of the anomeric bond. This approach demonstrates the power of Pd-catalysis C-H activation to access unusual cyclic peptides.

Electrogenerated Sm(II)-Catalyzed CO Activation for Carboxylation of Benzyl Halides.

Sm(II)-catalyzed carboxylation of benzyl halides is reported through the electrochemical reduction of CO. The transformation proceeds under mild reaction conditions to afford the corresponding phenylacetic acids in good to excellent yields. This user-friendly and operationally simple protocol represents an alternative to traditional strategies, which usually proceeds through the C(sp)-halide activation pathway.

CO activation by electrogenerated divalent samarium for aryl halide carboxylation.

The reductive carboxylation of aryl halides has been investigated using a samarium electrode as a sacrificial anode to yield the corresponding benzoic acids, providing a smooth strategy for CO2 activation. Carboxylation occurred after an efficient reduction of carbon dioxide mediated by an electrogenerated Sm(ii)-complex acting as a strong monoelectronic reductive reagent.