A copper-catalyzed aminoboration of bicyclic alkenes, including oxa- and azabenzonorbornadienes, has been developed. With this method, amine and boron moieties are simultaneously introduced at an olefin with exo selectivity. Subsequent stereospecific transformations of the boryl group can provide oxygen- and nitrogen-rich cyclic molecules with motifs that may be found in natural products or pharmaceutically active compounds. Moreover, a catalytic asymmetric variant of this transformation was realized by using a copper complex with a chiral bisphosphine ligand, namely (R,R)-Ph-BPE.

Double CH bond activation took place efficiently upon treatment of 3-phenylthiophenes with alkynes in the presence of a rhodium catalyst and a copper salt oxidant to form the corresponding naphthothiophene derivatives. Dehydrogenative coupling with alkenes was also found to occur on the phenyl moiety rather than the thiophene ring. These reactions provide straightforward synthetic methods for π-conjugated molecules involving a thiophene unit from readily available, simple building blocks.

Herein, we demonstrate that tritylamines undergo an unprecedented copper-mediated cyclization involving the cleavages of two CH bonds and one CN bond to give 9-arylacridine derivatives. This kind of acridines is of interest due to their biological properties and their unique optical and electro- and photochemical properties. Some of obtained acridine derivatives exhibit intense fluorescence in the solid state.

A copper-mediated C6-selective dehydrogenative heteroarylation of 2-pyridones with 1,3-azoles has been developed. The reaction proceeded smoothly by twofold CH cleavage even in the absence of noble-metal catalysts. The observed site selectivity was directed by a pyridyl substituent on the nitrogen atom of the pyridone ring. This directing group was readily removed after the coupling event, thus leading to 2-pyridone derivatives with a free NH group. Moreover, in some cases, catalytic turnover of the Cu salt was also possible with the ideal terminal oxidant: molecular oxygen in air.

It has been found that readily available hydroxylated cinnamic acids such as ferulic acid undergo palladium-catalyzed decarboxylative coupling with aryl iodides and internal alkynes in a 1:1:1 manner to produce 1,4-diarylbuta-1,3-dienes. The butadiene synthesis has also been achieved through the coupling of aryl halides with dienoic acids. Some of the products exhibit solid-state fluorescence.

Aromatic substrates with oxygen- and nitrogen-containing substituents undergo oxidative coupling with alkynes and alkenes under rhodium catalysis through regioselective CH bond cleavage. Coordination of the substituents to the rhodium center is the key to activate the CH bonds effectively. Various fused-ring systems can be constructed through these reactions.

We report a new approach to 2,3-diarylbenzo[b]thiophenes based on the nickel-catalyzed Suzuki–Miyaura cross-coupling/palladium-catalyzed decarboxylative arylation sequence of 3-chloro-2-methoxycarbonylbenzo[b]thiophenes, which are readily accessible from the corresponding cinnamic acids. In addition, this methodology can be applied to the concise synthesis of π-extended 2,3,6,7-tetraarylbenzo[1,2-b;4,5-b′]dithiophenes. Their optical properties are also described.

The cross-dimerization of diphenylacetylene with trimethylsilylacetylene via CH bond cleavage in the presence of a catalytic amount of bis(cyclooctadiene)nickel [Ni(cod)₂] together with a pyridine-based ligand efficiently proceeds to give the corresponding enyne compound with good yield. In contrast, their 1:2 cross-trimerization leading to a dienyne derivative takes place selectively using a triarylphosphine ligand. The regioselective cross-dimerization of some unsymmetrical internal arylalkynes with terminal silylacetylenes is also accomplished using the pyridine ligand.