The copper‐catalyzed intramolecular diastereoselective trifluoromethylcycloetherification of homoallylic alcohols with Togni’s reagent as trifluoromethylating reagent was realized under mild conditions. Various trifluoromethylated tetrahydrofurans were synthesized in moderate to good yields. Moreover, a wide range of common functional groups was tolerated.
A versatile strategy for the synthesis of fused cyclopentenones, key structural motifs in biologically relevant compounds such as indenones and indole alkaloids, has been established successfully through regioselective palladium‐catalyzed cyclization of 2‐iodoaryl allenols.
An efficient one‐pot method for the selective benzylation of diols and polyols using 0.1 equiv. of organotin reagents and tetrabutylammonium bromide as catalyst has been developed. The diols and polyols containing a cis‐vicinal diol were regioselectively benzylated in 70–94% isolated yields. A catalytic reaction mechanism was also proposed.
We report herein a highly enantioselective synthesis of multisubstituted biaryl chlorides/iodides by sequential halogenation reactions (desymmetrization/kinetic resolution sequence). The selectivity of biaryl chlorides/iodides obtained in the first asymmetric reaction (desymmetrization) could be enhanced by the kinetic resolution‐type asymmetric bromination to afford the corresponding chiral biaryl chlorides/iodides in excellent selectivities (up to 99 % ee).
Product selectivity control for the synthesis of imidoylindoles and 4‐alkylidenedihydroquinazolines from N‐imidoyl‐o‐alkynylanilines via silver triflate‐catalyzed cycloisomerization or tetrabutylammonium fluoride‐promoted cyclization is described. The product selectivity depends mainly on the catalyst/promoter used, and on the substituents on the alkyne and amidine functions of the substrates.
