Dong-Chao Wang

Microwave-promoted efficient synthesis of C6-cyclo secondary amine substituted purine analogues in neat water

The synthesis of C6-cyclo secondary amine-substituted purine analogues in neat water was achieved with the aid of microwave irradiation, providing a rapid, efficient and convenient method for the preparation of acyclic nucleosides in high yields.

Enantioselective Dearomative [3+2] Cycloaddition Reactions of Benzothiazoles

A highly enantioselective dearomative [3+2] cycloaddition of benzothiazole has been successfully developed. A wide range of benzothiazoles and cyclopropane-1,1-dicarboxylates are suitable substrates for this reaction. The desired hydropyrrolo[2,1-b]thiazole compounds were obtained in excellent enantioselectivity and yields (up to 97 % ee and 97 % yield). With the same catalytic system, a highly efficient kinetic resolution of 2-substituted cyclopropane-1,1-dicarboxylates was also realized.

Nickel-catalyzed sp2 C–H bonds arylation of N-aromatic heterocycles with Grignard reagents at room temperature

A novel protocol for nickel-catalyzed direct sp(2) C-H bond arylation of purines has been developed. This new reaction proceeded efficiently at room temperature using Grignard reagent as the coupling partner within 5 hours in good to high yields. This approach provides a new access to a variety of C8-arylpurines which are potentially of great importance in medicinal chemistry.

Microwave irradiated C6-functionalization of 6-chloropurine nucleosides with various mild nucleophiles under solvent-free conditions

An efficient method for the synthesis of C6-functionalized purine nucleosides was developed via the direct nucleophilic substitution reaction of 6-chloropurine derivatives with various mild nucleophiles. The eco-friendly solvent-free process gave good to high isolated yields within a short reaction time (5 min) under microwave irradiated conditions.

Highly Regioselective Three-Component Domino Heck–Negishi Coupling Reaction for the Functionalization of Purines at C6

A highly regioselective three-component domino Heck-Negishi coupling reaction has been developed. Organozinc reagents are used to trap an alkylpalladium intermediate of olefins for a first example in the domino Heck reaction. This reaction is applicable to acrylates (or acrylamides) and purine compounds, producing a series of novel purine compounds with carbon substituents at the C6 position in moderate to good yields.

Efficient, Green, Solvent-Free Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones via Biginelli Reaction Catalyzed by Cu(NO3)2·3H2O

The synthesis of 3,4-dihydropyrimidin-2-(1H)-ones derivatives via a three-component Biginelli reaction using copper nitrate as a catalyst under solventless conditions is reported, providing a green, rapid, efficient, and convenient method for the preparation of Biginelli compounds in good yields.

The synthesis of novel fluorescent purine analogues modified by azacrown ether at C6.

The synthesis and fluorescence properties of novel purine analogues linked azacrown ether at C6 position were investigated. These new purine analogues could be prepared from a series of 6-chloropurines and showed selective and efficient signaling behaviors toward micromolar concentration of Ag(+) ion over other common metal ions in an aqueous environment.

Microwave promoted C6-alkylation of purines through SNAr-based reaction of 6-chloropurines with 3-alkyl-acetylacetone

C6-Alkylated purine analogues were obtained in good to excellent isolated yields by S(N)Ar reaction of 6-chloropurine derivatives with 3-alkyl-acetylacetone. 3-Alkyl-acetylacetones were employed as alkylating agents and C6-alkylated purines were obtained highly selectively within short reaction time under microwave irradiation conditions. This work is complementary to the classical coupling reactions for the synthesis of C6-alkylated purine analogues.

Nickel-catalyzed Negishi cross-couplings of 6-chloropurines with organozinc halides at room temperature

An efficient method for the synthesis of 6-alkyl or 6-aryl purines (nucleosides) was developed via nickel-catalyzed Negishi cross-couplings of 6-chloropurines and organozinc halides. The ligand-free process gave good to excellent isolated yields at room temperature.

Enantioselective Friedel–Crafts Alkylation Reactions of β‐Naphthols with Donor–Acceptor Aminocyclopropanes

The enantioselective Friedel-Crafts alkylation reaction of β-naphthols with donor-acceptor aminocyclopropane was developed. In the presence of a copper complex derived from Cu(OTf)2 and bisoxazoline, a series of γ-substituted γ-aminobutyric acid derivatives were obtained with good yields (up to 98 %) and excellent enantioselectivities (up to 98 %). Using this catalytic system, the 2-amino cyclopropane-1,1-dicarboxylate was obtained with high enantiomeric excess (up to 98 %) by an efficient kinetic resolution (s values of up to 90). The Friedel-Crafts alkylation product could be transformed into a tetracyclic 1,3-oxazine derivative.