Synthesis of 2,3-Dihydrothieno(2,3-b)quinolines and Thieno(2,3-b)- quinolines via an Unexpected Domino Aza-MBH/Alkylation/Aldol Reaction.

An efficient, mild, and convenient method for the preparation of 2,3-dihydrothieno(2,3-b)quinolines and thieno(2,3-b)-quinolines via an unexpected domino aza-Morita-Baylis-Hillman/alkylation/aldol reaction has been developed. The plausible mechanisms for the unexpected reaction are also given.

Enantioselective Construction of Polyfunctionalized Spiroannulated Dihydrothiophenes via a Formal Thio [3+2] Cyclization.

A formal thio [3+2] cyclization catalyzed by Takemoto's organocatalyst has been reported for the construction of optically active spiroannulated dihydrothiophenes in high yields with excellent regio-, chemo-, diastereo-, and enantioselectivities.

Facile domino access to chiral mono-, bi-, and tricyclic 2,3-dihydrofurans.

The asymmetric domino Michael-S(N)2 reaction of various 1,3-dicarbonyl compounds to α-bromonitroalkenes is described for the first time, employing readily available cinchona-derived bifunctional thioureas as organocatalysts. The novel transformations were highly regio-, chemo-, diastereo-, and enantioselective, which simultaneously gave the chiral tricyclic 2,3-dihydrofurans, bicyclic 2,3-dihydrofurans, and tetrasubstituted 2,3-dihydrofurans with two vicinal chiral carbon centers.

Efficient kinetic resolution of racemic 3-nitro-2H-chromene derivatives catalyzed by Takemoto's organocatalyst.

Efficient kinetic resolution of racemic 3-nitro-2H-chromenes by bifunctional thiourea afforded optically active (R)-3-nitro-2H-chromene derivatives with moderate to good enantioselectivities, which simultaneously gave the multifunctional 3,4-diphenyl-3a-nitrobenzopyrano-[3,4-c]-pyrrolidine-1,1-dicarboxylate derivatives with four vicinal chiral carbon centers.

The organocatalytic two-step synthesis of diversely functionalized tricyclic tetrazoles.

The diversely functionalized tricyclic tetrazoles were synthesised from readily available substrates via intramolecular 1,3-dipolar cycloaddition as the key step in good yields (53-78% yield for two steps) with high enantioselectivities (81-99% ee).

Efficient method for the synthesis of functionalized pyrazoles by catalyst-free one-pot tandem reaction of nitroalkenes with ethyl diazoacetate.

The one-pot synthesis of multisubstituted pyrazole derivatives was achieved via catalyst-free 1,3-dipolar cycloaddition of ethyl diazoacetate and nitroalkenes as the key step and elimination of the leaving group (NO(2) or Br) followed by intramolecular proton transfer with satisfactory yields.