Build-up of double carbohelicenes using nitroarenes: dual role of the nitro functionality as an activating and leaving group.

The construction of double carbohelicenes is highly fascinating yet challenging work. Disclosed herein is a streamlined and simplified synthetic route to double carbohelicenes starting from nitroarenes through sequential nitro-activated -C-H arylation, denitrative alkenylation and intramolecular cyclodehydrogenation. In this synthetic strategy, the nitro group plays a dual role namely as a leaving group for the denitrative alkenylation and as an activating group for -C-H arylation, which is distinct from those of aryl halides in a conventional coupling reaction.

A methylation platform of unconventional inert aryl electrophiles: trimethylboroxine as a universal methylating reagent.

Methylation is one of the most fundamental conversions in medicinal and material chemistry. Extension of substrate types from aromatic halides to other unconventional aromatic electrophiles is a highly important yet challenging task in catalytic methylation. Disclosed herein is a series of transition metal-catalyzed methylations of unconventional inert aryl electrophiles using trimethylboroxine (TMB) as the methylating reagent.

Palladium-catalyzed denitrative Sonogashira-type cross-coupling of nitrobenzenes with terminal alkynes.

Described herein is a palladium-catalyzed cross-coupling reaction between nitroarenes and terminal alkynes, offering a facile method for C(sp)-C(sp) bond formation. The utility of this protocol has been proven by the construction of polycyclic aromatic hydrocarbons (PAHs) and orthogonal cross-coupling.

General rhodium-catalyzed oxidative cross-coupling reactions between anilines: synthesis of unsymmetrical 2,2'-diaminobiaryls.

Described herein is a dual chelation-assisted RhCl3-catalyzed oxidative C-H/C-H cross-coupling reaction of aniline derivatives. The highlight of this methodology is the chemo- and regioselective cross-coupling between electronically similar substrates, which represents a highly challenging task in oxidative Ar-H/Ar-H cross-coupling reactions. Furthermore, this Cp*-free catalytic reaction tolerates a range of functional groups and requires only a low molar ratio of coupling partners.