Wenwen Chen

Tandem Reaction of 1-Copper(I) Alkynes for the Synthesis of 1,4,5-Trisubstituted 5-Chloro-1,2,3-triazoles

A novel tandem reaction of 1-copper(I) alkynes with azides (cycloaddition) and then NCS (electrophilic substitution) was developed as an efficient method for the synthesis of 1,4,5-trisubstituted 5-chloro-1,2,3-triazoles. The method offers a rare example that a tandem reaction of an organometallic substrate does not involve in the reactivity of the metal-carbon bond in the first step.

Tandem Synthesis of 3-Chloro-4-iodoisoxazoles from 1-Copper(I) Alkynes, Dichloroformaldoxime, and Molecular Iodine

A tandem synthesis for structurally novel 3-chloro-4-iodoisoxazoles was developed by simply mixing 1-copper(I) alkynes, dichloroformaldoxime, and molecular iodine together. The combination of 1-copper(I) alkyne and molecular iodine was well used as a synthetic equivalent of 1-iodoalkyne without the need for tedious preparation, purification, and storage of 1-iodoalkyne.

Synthesis of N-Sulfonyl Arylaldimines Developed by Retesting an Old Process

By simply heating the mixture of an arylaldehyde and a sulfonylisocyanate in a solvent or in neat form under catalyst- and additive-free conditions, the desired N-sulfonylimine was produced with the release of carbon dioxide. The method is characterized by its unique clean efficiency, convenience, and scalability, but it was reported to fail half a century ago.

Tandem synthesis of 3-halo-5-substituted isoxazoles from 1-copper(I) alkynes and dihaloformaldoximes.

A tandem synthesis of 3-halo-5-substituted isoxazoles has been developed from 1-copper(I) alkynes and dihaloformaldoximes under base-free conditions. Thus, 1,3-dipolar cycloaddition and all its drawbacks can now be avoided completely.

One-pot three-component synthesis of 1,4,5-trisubstituted 5-iodo-1,2,3-triazoles from 1-copper(I) alkyne, azide and molecular iodine

Copper(I)-catalyzed cycloaddition of 1-iodoalkyne and azide has proven to be the most efficient method for the synthesis of 1,4,5-trisubstituted 5-iodo-1,2,3-triazoles, but pre-made 1-iodoalkyne is required. We find that the combination of 1-copper(I) alkyne and molecular iodine can serve as a synthetic equivalent of 1-iodoalkyne. Thus, the desired 5-iodo-1,2,3-triazole can be synthesized by simply mixing this combination and an azide together without the tedious synthesis of the corresponding 1-iodoalkyne.

Tandem Synthesis of α-Diazoketones from 1,3-Diketones

A highly efficient synthesis of α-diazoketone was achieved by simply stirring the mixture of 1,3-diketone, TsN3, and MeNH2 in EtOH. It was a tandem reaction including a novel primary amine-catalyzed Regitz diazo transfer of 1,3-diketone and a novel primary amine-mediated C-C bond cleavage of 2-diazo-1,3-diketone.

A general route for synthesis of N-aryl phenoxazines via copper(I)-catalyzed N-, N-, and O-arylations of 2-aminophenols

A novel copper(I)-catalyzed tandem reaction of N- and O-arylations of 2-[N-(2-chlorophenyl)amino]phenols was developed, by which a series of structurally novel N-aryl phenoxazines were synthesized efficiently. This success owes much to the discovery of highly efficient homogeneous copper(I)-catalyzed intramolecular O-arylation of chlorobenzenes under ligand-free-like conditions. Since 2-[N-(2-chlorophenyl)amino]phenols were prepared also by copper(I)-catalyzed N-arylation of 2-aminophenols, thus a general route for efficient synthesis of N-aryl phenoxazines was established via copper(I)-catalyzed N-, N-, and O-arylations of 2-aminophenols in two steps.