effective chiral dialkylsulfide organocatalysts remain relatively rare and under‐developed, despite the potential utility of dialkylsulfide catalysts. Herein, we report the development of chiral bifunctional dialkylsulfide catalysts possessing a urea moiety for regio‐, diastereo‐, and enantioselective bromolactonization. The importance of the bifunctional design of chiral sulfide catalysts was clearly
Trifluoroacetic acid catalyzed highly regioselective bromocyclization of styrene-type carboxylic acid
作者:Tao Chen、Ying-Yeung Yeung
DOI:10.1039/c6ob00756b
日期:——
A trifluoroaceticacid catalyzed highly 6-endo regioselective bromocyclization of styrene-type carboxylic acid has been developed. The resulting 3,4-dihydroisocoumarines are valuable building blocks in organic synthesis.
Divergent Thio/Selenolactonization of Styrene-Type Carboxylic Acids and Amides: Synthesis of Chalcogenated Isobenzofuran-1 (3H)-ones and Isochroman-1-ones
synthesis of isobenzofuran-1(3H)-one and 3,4-dihydroisochroman-1-one derivatives has been realized through the reaction of o-alkenyl benzoic acids/amides with PhICl2 and diphenyl disulfides/diselenides. Depending on the substitution type of the o-alkenyl benzoic acid or amide, this metal-free intramolecular oxychalcogenation approach regioselectively affords isobenzofuran-1(3H)-ones or 3,4-dihydroisochroman-1-ones
The novel synthesis of phenylselanylisochroman-1-ones was achieved by selenolactonization of styrene-typed carboxylic acids and phenylselenenyl chloride in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO). The reactions give excellent yields with high exo-selectivity.