Regioselective construction of polysubstituted benzene ring from Baylis–Hillman adduct via [4+2] annulation strategy

DBU-mediated [4 + 2] annulations of donor–acceptor cyclopropanes with 3-aryl-2-cyanoacrylates for the synthesis of fully substituted anilines

The diversity-oriented synthesis of fully substituted aniline derivatives via the DBU-mediated [4 + 2] annulation of donor-acceptor 1,1-dicyanocyclopropanes with 3-aryl-2-cyanoacrylate has been developed.

The reaction of porphyrins with α,β-acetylenic ketone/ester (Morita-Baylis-Hillman) promoted by MgI2 and subsequent Sonogashira coupling reactions

The stereoselective synthesis of (Z)-β-iodovinyl ketones/esters of Morita-Baylis-Hillman (MBH) porphyrin adducts has been achieved with a tandem formation of C - C and C - I bonds in a three-component reaction. The reaction is promoted by MgI 2 as a Lewis acid, as well as an iodine source for a Michael-type addition. The MBH adducts are efficiently oxidized to the corresponding ketones with Dess-Martin periodinane (DMP). These scaffolds are further used in a palladium-catalyzed Sonogashira carbon-carbon coupling reaction to obtain highly extended porphyrin systems.

BF3·Et2O-Catalyzed Direct Carbon−Carbon Bond Formation of α-EWG Ketene-(S,S)-Acetals and Alcohols and Synthesis of Unsymmetrical Biaryls

A highly efficient BF3.OEt2-catalyzed formal dehydration C-C coupling reaction between readily available alpha-EWG ketene-(S,S)-acetals and various alcohols via direct substitution of the hydroxy group in alcohols has been developed. On the basis of this C-C coupling reaction, a series of alkylated alpha-EWG ketene-(S,S)-acetals and functionalized 1,4-pentanedienes were prepared in high to excellent yields and the unsymmetrical biaryls were synthesized in good yields from the generated 1,4-pentanedienes and nitroalkanes through a one-pot annulation-aromatization process.