Gold- and Brønsted Acid-Catalyzed Cycloisomerization of 1,8-Diynyl Vinyl Acetates to Bicyclo[2.2.1]hept-2-en-7-ones.

A synthetic method for the efficient assembly of bicyclo[2.2.1]hept-2-en-7-ones that relies on gold(I)-catalyzed Rautenstrauch rearrangement followed by Brønsted acid-mediated formal [3 + 2]-cycloaddition/deacetylation of 1,8-diynyl vinyl acetates at room temperature under atmospheric conditions is described.

Gold-catalyzed benzannulation of 5-hydroxy-3-oxoalk-6-ynoate esters to o-phenolic esters.

A synthetic method to prepare o-phenolic esters efficiently by gold(I)-catalyzed benzannulation of 5-hydroxy-3-oxoalk-6-ynoate esters under mild conditions that did not require the exclusion of air or moisture is described.

Gold-catalyzed domino aminocyclization/1,3-sulfonyl migration of N-substituted N-sulfonyl-aminobut-3-yn-2-ols to 1-substituted 3-sulfonyl-1H-pyrroles.

A method to prepare 1-substituted 3-sulfonyl-1H-pyrroles efficiently that relies on the gold(I)-catalyzed cycloisomerization of N-substituted N-sulfonyl-aminobut-3-yn-2-ols is described. The method was shown to be applicable to a broad range of 1,7-enyne alcohols containing electron-withdrawing, electron-donating, and sterically demanding substrate combinations. The mechanism is suggested to involve activation of the propargylic alcohol by the Au(I) catalyst, which causes the intramolecular nucleophilic addition of the sulfonamide unit to the alkyne moiety.

Brønsted acid catalyzed cyclization of propargylic alcohols with thioamides. Facile synthesis of di- and trisubstituted thiazoles.

A general and efficient method to prepare 2,4-di- and trisubstituted thiazoles via p-TsOH·H(2)O-catalyzed cyclization of trisubstituted propargylic alcohols with thioamides is described. The reaction was accomplished in moderate to excellent product yields under mild conditions that did not require the exclusion of air and moisture and offers an operationally simplistic and convenient route to this synthetically useful aromatic heterocycle.

Ytterbium(III) triflate catalyzed tandem Friedel-Crafts alkylation/hydroarylation of propargylic alcohols with phenols as an expedient route to indenols.

A method to prepare indenols efficiently by ytterbium(III) triflate catalyzed tandem Friedel-Crafts alkylation/hydroarylation of propargylic alcohols with phenols is described. The reaction was accomplished in moderate to excellent yields and regioselectivity under mild conditions and offers a straightforward and convenient one step synthetic route to bioactive indenols and its derivatives.