Enantioselective Organocopper-Catalyzed Hetero Diels-Alder Reaction through in Situ Oxidation of Ethers into Enol Ethers

摘要

We disclose a catalytic method for the enantio- and diastereoselective union of alkyl ethers and heterodienes. Wedemonstrate that a chiral Cu-BOX complex catalyzes the efficient oxidation of ethers into enol ethers in the presence of tritylacetate. Then, the organocopper promotes stereoselective hetero Diels-Alder reaction between thein situgenerated enol ethers and beta,gamma-unsaturated ketoesters, allowing for rapid access to an array of dihydropyran derivatives possessing three vicinal stereogeniccenters.