Palladium-Catalyzed Insertion of <i>N</i>‑tosylhydrazones and Trapping with Carbon Nucleophiles

A Pd-catalyzed three-component cross-coupling reaction of vinyl iodide, <i>N</i>-tosylhydrazone, and carbon nucleophiles is reported, and a one-pot procedure is also developed. The cross-coupling is proposed to proceed through a palladium–carbene migratory insertion, carbopalladation other than classic palladium–carbene migratory insertion, and β-H elimination. Moreover, the reaction proceeds under mild conditions and with high stereoselectivity

Palladium-Catalyzed Carbene Migratory Insertion and Trapping with Sulfinic Acid Salts toward Allylic Sulfones

Allylic sulfones were synthesized with excellent selectivity and good yield via Pd-catalyzed cross-coupling of vinyl iodide with <i>N</i>-tosylhydrazone. This process involves palladium carbene migratory insertion/​trapping with sulfinic acid salts. For the previous Pd-catalyzed <i>N</i>-tosylhydrazone cross-coupling, sulfinic acid salt is generated as a byproduct. In this transformation, the diazo compound and the sulfinic acid salt, which are all generated from <i>N</i>-tosylhydrazone, were used as cross-coupling partner

Palladium-Catalyzed Carbene Migratory Insertion and Trapping with Sulfinic Acid Salts toward Allylic Sulfones

Allylic sulfones were synthesized with excellent selectivity and good yield via Pd-catalyzed cross-coupling of vinyl iodide with <i>N</i>-tosylhydrazone. This process involves palladium carbene migratory insertion/​trapping with sulfinic acid salts. For the previous Pd-catalyzed <i>N</i>-tosylhydrazone cross-coupling, sulfinic acid salt is generated as a byproduct. In this transformation, the diazo compound and the sulfinic acid salt, which are all generated from <i>N</i>-tosylhydrazone, were used as cross-coupling partner

Silver-Promoted Oxidative Cyclization of 1,6-Enynes: Highly Regioselective Synthesis of Phosphorated Fluorene Derivatives

A silver-promoted oxidative cyclization of 1,6-enynes with disubstituted phosphine oxides is developed for the synthesis of fluorene derivatives. The reaction proceeds with high regioselectivity by constructing one C–P bond and two C–C bonds in one step. Moreover, reduction of the pentavalent phosphine enlarges the application scope of the product

Silver-Promoted Oxidative Cyclization of 1,6-Enynes: Highly Regioselective Synthesis of Phosphorated Fluorene Derivatives

A silver-promoted oxidative cyclization of 1,6-enynes with disubstituted phosphine oxides is developed for the synthesis of fluorene derivatives. The reaction proceeds with high regioselectivity by constructing one C–P bond and two C–C bonds in one step. Moreover, reduction of the pentavalent phosphine enlarges the application scope of the product

Iodine-Promoted Radical Cyclization in Water: A Selective Reaction of 1,6-Enynes with Sulfonyl Hydrazides

An iodine-promoted one-pot radical cyclization reaction of 1,6-enynes with sulfonyl hydrazides to provide five-membered and hexatomic ring sulfonylated products under the same conditions is established. This reaction proceeded smoothly in water and gave the corresponding products by using I₂/TBHP instead of expensive and toxic catalysts with C–S and C–I bond formed in one step. This method also allowed easy access to significant functional sulfones for potential applications in medicinal and organic chemistry

Palladium-Catalyzed/Norbornene-Mediated <i>ortho</i>-Amination/<i>N</i>‑Tosylhydrazone Insertion Reaction: An Approach to the Synthesis of <i>ortho</i>-Aminated Vinylarenes

<i>ortho</i>-Aminated vinylarene derivatives were obtained via a reaction of aryl iodides, <i>N</i>-benzoyloxyamines, and <i>N</i>-tosylhydrazones. This approach involves a palladium-catalyzed, norbornene-mediated <i>ortho</i>-amination/<i>N</i>-tosylhydrazone insertion reaction. In this transformation, one C–N bond and one C–C bond are formed and an amine group is introduced at the <i>ortho</i> position successfully

Palladium-Catalyzed Acylation/Alkenylation of Aryl Iodide: A Domino Approach Based on the Catellani–Lautens Reaction

A new palladium-catalyzed three-component coupling involving acylation/alkenylation of aryl iodide is reported. The reaction was carried out with readily available starting materials and gave the ortho-acylated styrene in moderate to good yields. Compared with previous Catellani–Lautens reactions, this reaction is the first example of introducing an acyl group at the ortho position of aryl iodides. The proposed Pd^IV complex, generated via oxidative addition of the carboxylic anhydrides, is a key intermediate for this transformation