Polyamino acid-catalyzed process for the enantioselective epoxidation of α,β-unsaturated enones and α,β-unsaturated sulfones
View Patent ↗The invention relates to a novel process that makes it possible to epoxidize α,β-unsaturated enones or α,β-unsaturated sulfones with high conversions and enantiomeric excesses in a two-phase system without addition of water in the presence of an organic solvent, a base, an oxidant, a diastereomer- and enantiomer-enriched homo-polyamino acid that has not been separately preactivated as catalyst, and a specific phase-transfer catalyst as cocatalyst.
1. A process comprising epoxidizing at least one α,β-unsaturated sulfone or at least one α,β-unsaturated sulfone in the presence of
(1) an organic solvent,
(2) a base,
(3) an oxidant,
(4) a diastereomer- and enantiomer-enriched homo-polyamino acid as a catalyst that has not been separately preactivated, and
(5) a phase-transfer catalyst, without addition of water,
wherein the homo-polyamino acid is applied by adsorption to an insoluble support material.
2. A process according to claim 1 wherein the insoluble support material is based on a material selected from the group consisting of silica, zeolite, activated carbon, sugar derivatives, and combinations thereof.