Photocatalyzed cross-dehydrogenative coupling of silanes with alcohols and water.

An efficient method for the dehydrogenative coupling of silanes with alcohols under photocatalysis was developed. The reaction proceeded in the presence of Ru(bpy)Cl (0.5 mol%) under visible light irradiation in acetonitrile at room temperature.

Cobalt-catalyzed ring-opening addition of azabenzonorbornadienes via C(sp)-H bond activation of 8-methylquinoline.

The first ring-opening addition of a benzylic C(sp)-H bond to azabenzonorbornadienes is demonstrated. The reaction proceeded under the catalytic system of [Cp*CoI(CO)], AgSbF and Fe(OAc) in PhOMe. The methodology showed a good substrate scope with up to 96% yield.

Directing-Group-Controlled Ring-Opening Addition and Hydroarylation of Oxa/azabenzonorbornadienes with Arenes via C-H Activation.

An efficient method for the directing group controlled rhodium-catalyzed addition reaction of oxa/azabicylic alkenes with aromatic ketones and benzoic acids has been developed. The ketones and benzoic acids afforded different addition products when reacted with oxa/azabicyclic alkenes. The reaction between ketones and azabenzonorbornadienes furnished the ring-opening addition products.

Rhodium-catalyzed transfer hydrogenation of quinoxalines with water as a hydrogen source.

Rhodium-catalyzed transfer hydrogenation of quinoxalines with water as a hydrogen source was reported. The reaction allowed the simple preparation of tetrahydroquinoxalines under mild conditions. The deuterium-labelling experiment confirmed that water is the sole hydrogen source in the transfer hydrogenation reaction.

One stone two birds: cobalt-catalyzed in situ generation of isocyanates and benzyl alcohols for the synthesis of N-aryl carbamates.

An efficient method for the synthesis of N-aryl carbamates from N-Boc-protected amines has been developed. The cobalt-catalyzed in situ generation of isocyanates from N-Boc-protected amines and benzyl alcohols from benzyl formates has been achieved for the first time, which in turn furnished the corresponding benzyl carbamates in moderate to high yields. The reaction was catalyzed by CoI with tris-(4-dimethylaminophenyl)-phosphine as the ligand and zinc powder as the reductant.

Cobalt catalyzed stereodivergent semi-hydrogenation of alkynes using HO as the hydrogen source.

Cobalt-catalyzed stereodivergent semi-hydrogenation of internal alkynes to alkenes is developed. The reaction proceeded through transfer hydrogenation under mild conditions using a base metal CoI2 as the catalyst, and H2O/MeOH as the hydrogen source with Zn as the reductant. The E/Z-selectivity of the product could be switched by changing the solvent and by inclusion/exclusion of a bidentate phosphine ligand (dppe).

Synthesis of o-Methyl Trifluoromethyl Sulfide Substituted Benzophenones via 1,2-Difunctionalization of Aryne by Insertion into the C-C Bond.

An efficient process for the preparation of valuable o-methyl trifluoromethyl sulfide substituted benzophenones has been developed. The transition-metal-free method features insertion of aryne into a C-C σ-bond under mild reaction conditions for the first time to achieve ortho-difunctionalized arenes containing a pharmaceutically important trifluoromethylthio functional group. A wide substrate scope has been demonstrated for the developed protocol.