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An efficient AgOTf-catalyzed (TfO = trifluoromethanesulfonate) cyclopropyl carbinol rearrangement for the synthesis of benzo[ b]oxepines and 2 H-chromenes is reported by starting from 2-[cyclopropyl(hydroxy)methyl]phenols. The reactions proved to be general in scope and furnished a range of the corresponding functionalized oxygen heterocycles. The formation of the benzo-fused six-membered adduct is proposed to result from the ring-contraction of the benzo[ b]oxepine derivative. Control of the product selectivity is achievable by fine-tuning the reaction time. The catalytic synergy between the silver(I) cation and the triflate anion was essential for optimal product yields. [ABSTRACT FROM AUTHOR]

A synthetic method to prepare o-phenolic estersefficiently by gold(I)-catalyzed benzannulation of 5-hydroxy-3-oxoalk-6-ynoateesters under mild conditions that did not require the exclusion ofair or moisture is described. [ABSTRACT FROM AUTHOR]

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.

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.