Highly Efficient Catalysis of Retro-Claisen Reactions: From a Quinone Derivative to Functionalized Imidazolium Salts

Gold-Catalyzed 1,3-Thiazine Formation and Uncommon Tautomer Isolation

This work represents the first example of a gold-catalyzed formation of 1,3-thiazine/1,3-thiazinane by means of a catalytic approach and further uncommon isolation of the two tautomers. The developed protocol gives rise to a broad scope of 1,3-thiazine derivatives with excellent yields in short reaction times. Interestingly, different isomers could be obtained depending on the state of the compound, and in the crystal state the 1,3-thiazinane isomer is obtained, while in solution the 1,3-thiazine is the unique isomer. This work represents an interesting approach for the synthesis of potential biologically relevant molecules and a crucial precedent in tautomerism isolation and characterization.

An efficient method for retro-Claisen-type C–C bond cleavage of diketones with tropylium catalyst

We report a new convenient and efficient method utilizing the tropylium ion as a mild and environmentally friendly organocatalyst to mediate retro-Claisen-type reactions.

A novel strategy to construct Janus metallamacrocycles with both a Ru–arene face and an imidazolium face

We report a novel strategy to synthesize Janus metallocyclic Ru–arene complexes with both a Ru–arene face and a didentate imidazolium face, which possess unusual structures and properties.