Copper-Catalyzed Radical Hydrazono-Phosphorylation of Alkenes.

An efficient copper-catalyzed radical hydrazono-phosphorylation of alkenes with hydrazine derivatives and diarylphosphine oxides is described. The reaction provides a general and convenient method toward the synthesis of diverse ß-hydrazonophosphine oxides in satisfactory yields. Based on conducted mechanistic experiments, a mechanism involving Ag-catalyzed oxidative generation of phosphinoyl radicals and subsequent addition to alkenes followed by Cu-assisted hydrazonation is proposed. Moreover, the practicability of the reaction is successfully demonstrated by its successful application on a gram scale.

Copper-Catalyzed Stereoselective Radical Phosphono-hydrazonation of Alkynes.

A copper-catalyzed stereoselective phosphono-hydrazonation of terminal alkynes with alkyl carbazates and diarylphosphine oxides is described. This methodology provides facile access to a variety of ß-hydrazonophosphine oxides in satisfactory yields. The reaction proceeds under mild conditions and exhibits good functional group tolerance. A mechanism featuring persulfate-mediated oxidative generation of phosphinoyl radicals and copper-assisted hydrazonation is proposed.

Copper-Catalyzed Cross-Coupling of Alkyl and Phosphorus Radicals for C(sp3)-P Bond Formation.

A CuI-catalyzed cross-coupling of alkyl- and phosphorus-centered radicals for C(sp3)-P bond formation is introduced. Diacyl peroxides, generated in situ from aliphatic acids and H2O2, serve as a source for alkyl radicals and also an initiator for the generation of phosphorus radicals from H-P(O) compounds.

Copper-Catalyzed Coupling of Amines with Carbazates: An Approach to Carbamates.

A new approach for the preparation of carbamates via the copper-catalyzed cross-coupling reaction of amines with alkoxycarbonyl radicals generated from carbazates is described. This environmentally friendly protocol takes place under mild conditions and is compatible with a wide range of amines, including aromatic/aliphatic and primary/secondary substrates.

Copper-Catalyzed Vicinal Cyano-, Thiocyano-, and Chlorophosphorylation of Alkynes: A Phosphinoyl Radical-Initiated Approach for Difunctionalized Alkenes.

A copper-catalyzed difunctional cyano-, thiocyano-, and chlorophosphorylation reaction of alkynes with P(O)-H compounds and coupling partners (TBACN, TMSNCS, TMSCl) is described. The reaction introduces versatile groups (-P(O)R2 and -CN, -SCN, or -Cl) to form tri- and tetrasubstituted alkenyl phosphine oxides/phosphonates regio- and stereoselectively.

Visible Light-Mediated Photocatalytic Metal-Free Cross-Coupling Reaction of Alkenyl Carboxylic Acids with Diarylphosphine Oxides Leading to ß-Ketophosphine Oxides.

A new visible light-mediated photocatalytic decarboxylative oxyphosphorylation of cinnamic acids with diarylphosphine oxides is described. This reaction is performed under mild conditions to afford the corresponding ß-ketophosphine oxides.

Phosphinoyl Radical-Initiated 1,2-Bifunctional Thiocyanodiphenylphosphinoylation of Alkenes.

1,2-Bifuctional thiocyanodiphenylphosphinoylation of alkenes is established through the phosphinoyl radical addition followed by Cu-catalyzed thiocyanation. This one-pot reaction is applicable to a range of aromatic, aliphatic, and cyclic alkenes to afford thiocyanodiphenylphosphinoylated compounds in satisfactory yields.

Phosphinoyl Radical Initiated Vicinal Cyanophosphinoylation of Alkenes.

A double-functionalization reaction of alkenes through Mn(OAc)3-mediated phosphinoyl radical addition followed by CuCN-catalyzed cyanation is introduced. This one-pot reaction is performed under mild conditions to afford vicinal cyanophosphinoylation products.

Phosphinoyl Radical-Initiated α,ß-Aminophosphinoylation of Alkenes.

A new double functionalization reaction of alkenes through AgNO3-mediated phosphinoyl radical addition followed by Cu(II)-catalyzed amination is introduced. This one-pot, three-component reaction is performed under mild conditions to afford α,ß-aminophosphinoylation products.

Copper-Catalyzed TBHP-Mediated Radical Cross-Coupling Reaction of Sulfonylhydrazides with Thiols Leading to Thiosulfonates.

A tert-butyl hydroperoxide (TBHP)-mediated coupling of sulfonylhydrazides with thiols catalyzed by CuBr2 to afford thiosulfonates via a radical process is described.

Copper-catalyzed TEMPO oxidative cleavage of 1,3-diketones and ß-keto esters for the synthesis of 1,2-diketones and α-keto esters.

A copper-catalyzed efficient and practical method has been developed for the synthesis of 1,2-diketones and α-keto esters. TEMPO was used as a radical initiator and scavenger, oxidizing the cleavage of α-methylene of 1,3-diketones and ß-keto esters to form 1,2-diketones and α-keto esters. This method provided a general way for the formation of 1,2-dicarbonyl compounds.

Air Oxidative Radical Oxysulfurization of Alkynes Leading to α-Thioaldehydes.

Air oxidative radical oxysulfurization of alkynes initiated by 0.5 mol % tert-butyl hydroperoxide with arylthiols is described. The reaction proceeded at room temperature in the presence of 5% mol water to afford selective α-thioaldehydes.

Air oxidative radical hydroxysulfurization of styrenes leading to ß-hydroxysulfides.

Air oxidative radical hydroxysulfurization of styrenes initiated by 0.5 mol % of tert-butyl hydroperoxide with arylthiols is described, and a new type of difunctionalization of alkenes was achieved.