Azhong Wang

Palladium-Catalyzed Diacetoxylation of Alkenes with Molecular Oxygen as Sole Oxidant

A new palladium-catalyzed diacetoxylation of alkenes using oxygen as the sole oxidant to afford diacetates was developed. High levels of diastereoselectivity in diacetoxylation of 1,2-disubstituted alkenes was obtained.

Synthesis of Amides via Palladium-Catalyzed Amidation of Aryl Halides

A new and efficient method for the synthesis of amides via palladium-catalyzed C-C coupling of aryl halides with isocyanides is reported, by which a series of amides were formed from readily available starting materials under mild conditions. This transformation could extend its use to the synthesis of natural products and significant pharmaceuticals.

Palladium-catalyzed cleavage reaction of carbon-carbon triple bond with molecular oxygen promoted by Lewis acid.

A new Lewis acid promoted and palladium-catalyzed cleavage reaction of carbon-carbon triple bond with molecular oxygen was reported, in which alkyne or 1.3-diynes is split into carboxylic ester in various alcohols.

Palladium-catalyzed direct oxidation of alkenes with molecular oxygen: general and practical methods for the preparation of 1,2-diols, aldehydes, and ketones.

1,2-Diols, aldehydes, and ketones are important intermediates in chemical synthesis, and alkenes are possible precursors for 1,2-diols, aldehydes, and ketones. Herein, novel and environmentally benign methods for palladium-catalyzed dihydroxylation and oxidative cleavage of olefins with oxygen as sole oxidant are presented. The cleavage reactions were performed with acid as additive in aqueous solution, whereas 1,2-diols were formed in the presence of base. A broad substrate scope has been demonstrated allowing monosubstituted aromatic and aliphatic terminal alkenes, 1,2-disubstituted, and 1,1-disubstituted olefins. The cleavage reactions of dioxo-Pd(II) complexes implicate 1,2-diol might act as a key intermediate of olefin cleavage.

Transition-Metal-Free Homocoupling of 1-Haloalkynes: A Facile Synthesis of Symmetrical 1,3-Diynes

Symmetrical 1,3-diyne compounds can be easily synthesized via a transition-metal-free homocoupling reaction of 1-haloalkynes without base and oxidant. The method shows excellent functional group compatibility and high yields.

Palladium-catalyzed acetoxylation of sp3 C–H bonds using molecular oxygen

Molecular oxygen as oxidant to promote palladium-catalyzed acetoxylation of sp(3) C-H bonds to afford α-oxygenated products is reported.

Highly chemoselective palladium-catalyzed cross-trimerization between alkyne and alkenes leading to 1,3,5-trienes or 1,2,4,5-tetrasubstituted benzenes with dioxygen.

A palladium-catalyzed 1:2 linear/cyclic cross-trimerization of alkyne with alkenes using molecular oxygen as the sole oxidant has been reported for the first time. A series of 1,3,5-trienes and 1,2,4,5-tetrasubstituted benzenes are obtained with high chemoselectivity respectively and mechanisms of these reactions are proposed based on some controlled examination.

Palladium-catalyzed carbonation-diketonization of terminal aromatic alkenes via carbon-nitrogen bond cleavage for the synthesis of 1,2-diketones.

A palladium-catalyzed carbonation-diketonization reaction of terminal alkenes via carbon-nitrogen bond cleavage under an atmosphere of oxygen has been developed. A series of 1,2-diketones were readily prepared from the reaction of aromatic terminal alkenes with nitroalkanes.