Photo-Promoted Decarboxylative Alkylation of ,-Unsaturated Carboxylic Acids with ICHCN for the Synthesis of ,-Unsaturated Nitriles.

An efficient, catalyst/photocatalyst-free, and cost-effective methodology for the decarboxylative alkylation of ,-unsaturated carboxylic acids to synthesize ,-unsaturated nitriles has been developed. The reaction proceeded in an environmentally benign atmosphere of blue light-emitting diode irradiation with KCO and water at room temperature. The methodology worked for a wide range of substrates (22 examples) with up to 83% yield.

Blue Light Promoted Difluoroalkylation of Aryl Ketones: Synthesis of Quaternary Alkyl Difluorides and Tetrasubstituted Monofluoroalkenes.

A facile and cost-effective method for the preparation of fluoroalkylated compounds has been described by the direct photoexcitation of halofluoroalkanes with blue light absorptivity, enabling the difluoroalkylation of aryl ketones. The methodology has provided an efficient, mild, and catalyst-free synthetic method for quaternary difluoroalkylated arenes and tetrasubstituted monofluoroalkenes.

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.

Blue Light Induced Difluoroalkylation of Alkynes and Alkenes.

The difluoroalkylation of alkynes and alkenes by direct photoexcitation of ethyl difluoroiodoacetate is described. Under catalyst- and oxidant-free conditions, iododifluoroalkylation and hydrodifluoroalkylation products were generated from alkynes, and difluoroalkylation products were prepared from alkenes. This methodology provides a streamlined access to difluoroalkylated organic compounds starting from simple alkynes or alkenes.

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).

Pd(ii)/Zn co-catalyzed chemo-selective hydrogenation of α-methylene-γ-keto carboxylic acids.

An efficient Pd/Zn co-catalyzed chemo-selective hydrogenation of α-methylene-γ-keto carboxylic acids is described. This methodology offers a divergent synthesis of α-methyl-γ-keto carboxylic acids, α-methylcarboxylic acids, and lactones starting from α-methylene-γ-keto carboxylic acids via selective hydrogenation by varying the catalytic conditions avoiding the use of high pressure of hydrogen. The reaction also showed broad substrate tolerance to give the desired products in good to excellent yields.

Nickel-Catalyzed Asymmetric [2+2] Cycloaddition Reaction of Hetero-Bicyclic Alkenes with Internal Alkynes.

Enantioselective [2+2] cycloaddition reaction of azabenzonorbornadienes and oxabenzonorbornadienes with internal alkynes has been enabled by a catalyst system comprising Ni(COD) and (R)-SIPHOS-Ph-Mor. This transformation represents the first asymmetric [2+2] cycloaddition reaction of azabenzonorbornadienes with internal alkynes, providing a straightforward method to prepare four-membered carbocycles.