Zinc-catalyzed [4+3] cycloaddition with concomitant furan annulation: formation of cyclohepta[b]furans.

A convenient zinc-promoted [4+3] cycloaddition of a carbonyl ene-yne with simple dienes was first achieved. This reaction provided an efficient strategy to prepare various cyclohepta[b]furan rings by cascade cycloadditions. Additionally, a multicomponent reaction of dione, alkynal, and diene was also reported, which exhibited a novel strategy for selective creations of C-O bonds and C-C bonds.

Facile synthesis of halogenated spiroketals via a tandem iodocyclization.

A strategy for the synthesis of spiroketal compounds through a tandem iodocyclization of 1-(2-ethynylphenyl)-4-hydroxybut-2-yn-1-one derivatives is presented. This reaction could proceed under very mild conditions in a short time and avoid the use of expensive and toxic metal catalysts. Moreover, the resulting halides can be further exploited by subsequent palladium-catalyzed coupling reactions, which act as the important intermediates for building other valuable compounds.

Brønsted acid catalyzed and NIS-promoted cyclization of diynones: selective synthesis of 4-pyrone, 4-pyridone, and 3-pyrrolone derivatives.

Brønsted acid catalyzed tandem cyclization was found to be highly effective for the preparation of a series of polysubstituted 4-pyrones from diynones (yield up to 99%). 4-Pyridone and 3-pyrrolone derivatives were also selectively synthesized by employing NIS and/or Brønsted acid. NIS as an electrophilic reagent could promote these reactions efficiently and rapidly under very mild reaction conditions.

Palladium-catalyzed insertion of α,β-unsaturated N-tosylhydrazones and trapping with carbon nucleophiles.

Palladium-catalyzed carbene migratory insertion-cyclization reactions were reported, delivering dihydronaphthalene and indene derivatives in moderate to good yields. A three-component cross-coupling was also developed. The reactions are easy to handle, under mild conditions and various functional groups are tolerated.

Synthesis of tetrasubstituted cyclopentadienes via palladium-catalyzed reaction of (Z)-2-en-4-yn acetates and N-methyl indoles.

An efficient approach for the synthesis of tetrasubstituted cyclopentadienes through Pd-catalyzed reactions of (Z)-2-en-4-yn acetates with substituted indoles was developed. This methodology has the advantages of broad scope, simple conditions and easily accessible starting materials.

Facile synthesis of 2-iodo-spiro[indene-1,1'-isobenzofuran]-3'-ones via iodine-promoted cascade cyclization.

A novel and efficient synthetic approach to substituted 2-iodo-spiro[indene-1,1'-isobenzofuran]-3'-ones has been developed via an iodine-promoted cascade cyclization of 2-(3-hydroxy-3,3-diarylprop-1-yn-1-yl)benzoates. This sequential cascade process is concisely conducted at room temperature. Subsequent palladium-catalyzed Sonogashira, Suzuki, and Heck reactions of the resulting iodides proceed smoothly in good yields.

One pot synthesis of indene through copper(I)-catalyzed three-components coupling and cyclization reaction.

A new and efficient synthesis of substituted indene has been achieved via copper(I)-catalyzed domino three-component coupling and cyclization reaction in moderate to good yield.

Bi(III)-catalyzed intermolecular reactions of (Z)-pent-2-en-4-yl acetates with ethynylarenes for the construction of multisubstituted fluorene skeletons through a cascade electrophilic addition/cycloisomerization sequence.

A Bi(III)-catalyzed method for the synthesis of highly conjugated aromatic multisubstituted fluorene with (Z)-pent-2-en-4-yl acetates and ethynylarenes via domino reaction is described. In this process, the reaction appears to be very general and suitable for a variety of multisubstituted fluorene.

Copper-catalyzed dimerization fragmentation cyclization reactions of (E)-1-en-4-yn-3-ols as a versatile approach for the synthesis of multisubstituted 1H-cyclopenta[b]naphthalenes.

An intermolecular condensation reaction of 1,3,5-triarylenynols catalyzed by copper is developed. This reaction is a straightforward method for the synthesis of highly conjugated 1H-cyclopenta[b]naphthalene. Fluorescent properties have been determined for some of the products.