Ping-Xin Zhou

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

ortho-Aminated vinylarene derivatives were obtained via a reaction of aryl iodides, N-benzoyloxyamines, and N-tosylhydrazones. This approach involves a palladium-catalyzed, norbornene-mediated ortho-amination/N-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 ortho position successfully.

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.

Palladium‐Catalyzed/Norbornene‐Mediated CH Activation/ N‐Tosylhydrazone Insertion Reaction: A Route to Highly Functionalized Vinylarenes

A straightforward method for the synthesis of highly functionalized vinylarenes through palladium-catalyzed, norbornene-mediated C-H activation/carbene migratory insertion is described. Extension to a one-pot procedure is also developed. Furthermore, this method can also be used to generate polysubstituted bicyclic molecules. The reaction proceeds under mild conditions to give the products in satisfactory yields using readily available starting materials. This is a Catellani-Lautens reaction that incorporates different types of coupling partners. Additionally, this reaction is the first to demonstrate the possibility of combining Pd-catalyzed insertion of diazo compounds and Pd-catalyzed C-H activation.

Synthesis of polycyclic substituted vinylarenes via a one-pot intramolecular aryl alkylation–N-tosylhydrazone insertion reaction

A novel method of a palladium-catalyzed/norbornene-mediated intramolecular C-H activation/N-tosylhydrazones insertion reaction is developed. In this process, various bicyclic or tricyclic substituted vinylarenes are obtained with high efficiency under mild conditions.

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.

Regioselective access to CF3S-substituted dihydrofurans from homopropargylic alcohols with trifluoromethanesulfenamide

A facile access to 4-((trifluoromethyl)thio)-2,3-dihydrofurans from unprotected homopropargylic alcohols in high regioselectivity is reported. This method is the first example of using a free hydroxy group as a nucleophile to complete a trifluoromethylthiolation/cyclization protocol with an alkyne in moderate to excellent yields.

Zinc-Catalyzed [4+3] Cycloaddition with Concomitant Furan Annulation: Formation of Cyclohepta[b]Furans

A convenient zinc-promoted [4+3] cycloaddition of a carbonyl ene-yne with simple dienes was first achieved. This reaction provided an efficient strategy to prepare various cyclohepta[b]furan rings by cascade cycloadditions. Additionally, a multicomponent reaction of dione, alkynal, and diene was also reported, which exhibited a novel strategy for selective creations of C-O bonds and C-C bonds.

Palladium-catalyzed insertion of N-tosylhydrazones and trapping with carbon nucleophiles.

A Pd-catalyzed three-component cross-coupling reaction of vinyl iodide, N-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.

Using N-Tosylhydrazone as a Double Nucleophile in the Palladium-Catalyzed Cross-Coupling Reaction To Synthesize Allylic Sulfones

Without extra addition of sulfinate salt, allylic sulfones were synthesized by palladium-catalyzed cross-coupling of aryl iodide with N-tosylhydrazone. In this transformation, not only the diazo compound but also the sulfinate salt, which were both generated in situ from base-mediated decomposition of the N-tosylhydrazone, was used as nucleophilic partner.