Access to enantioenriched compounds bearing challenging tetrasubstituted stereocenters via kinetic resolution of auxiliary adjacent alcohols

Contemporary asymmetric catalysis faces huge challenges when prochiral substrates bear electronically and sterically unbiased substituents and when substrates show low reactivities. One of the inherent limitations of chiral catalysts and ligands is their incapability in recognizing prochiral substrates bearing similar groups. This has rendered many enantiopure substances bearing several similar substituents inaccessible. Here we report the rationale, scope, and applications of the strategy of kinetic resolution of auxiliary adjacent alcohols (KRA*) that can be used to solve the above troubles. Using this method, a large variety of optically enriched tertiary alcohols, epoxides, esters, ketones, hydroxy ketones, epoxy ketones, β-ketoesters, and tetrasubstituted methane analogs with two, three, and four spatially and electronically similar groups can be readily obtained (totally 96 examples). At the current stage, the strategy serves as the optimal solution that can complement the inability caused by direct asymmetric catalysis in getting chiral molecules with challenging fully substituted stereocenters.

Synthesis of α,β-unsaturated Epoxy Ketones Utilizing a Bifunctional Sulfonium/Phosphonium Ylide

Herein, a new protocol for rapid synthesis of α,β-unsaturated epoxy ketones utilizing a bifunctional sulfonium/phosphonium ylide is described. This approach comprises two sequential chemoselective reactions between sulfonium and phosphonium ylides...

Peroxide- and transition metal-free electrochemical synthesis of α,β-epoxy ketones

A novel electrochemical method for the synthesis of α,β-epoxy ketones is reported.

Solvent-free preparation of 3-aryl-2-[(aryl)(arylamino)]methyl-4H-furo[3,2-c]chromen-4-one derivatives using ZnO-ZnAl2O4 nanocomposite as a heterogeneous catalyst

The title compounds were synthesized by a three-component reaction of 4-hydroxycoumarin, aromatic amines and α,β-epoxy ketones, catalyzed by ZnO-ZnAl2O4 nanocomposite.

Design and synthesis of bi-functional Co-containing zeolite ETS-10 catalyst with high activity in the oxidative coupling of alkenes with aldehydes for preparing α,β-epoxy ketones

Developing highly efficient heterogeneous catalysts for organic synthesis is of great importance in modern synthetic chemistry.

One-pot synthesis of α,β-epoxy ketones through domino reaction between alkenes and aldehydes catalyzed by proline based chiral organocatalysts

A proline based metal free organocatalysts developed by new approach for the synthesis of epoxide derivatives through domino reaction. This domino reaction allows the direct access to epoxide from various alkene and aldehyde through C–H functionalization and C–C/C–O bond formation. The catalytic efficiencies of organocatalysts were also determined by domino reaction with very good yield (up to 95 %) and ee's (up to 99 %).