Ligand controlled highly regio- and enantioselective synthesis of alpha-acyloxyketones by palladium-catalyzed allylic alkylation of 1,2-enediol carbonates.
The palladium catalyzed decarboxylative asymmetric allylic alkylation of allyl 1,2-enediol carbonates 1 can decompose to either alpha-hydroxyketones 3 or alpha-hydroxyaldehydes 4. The product distribution is largely controlled by the ligand. Using Lnaph in DME we exclusively obtained the ketone product in good to excellent yields and high enantiomeric excesses. The reaction proceeds under extremely mild conditions, so we can have a broad range of choices of OR. Besides the commonly used protection groups such as OAc and OPiv, a more functionalized group such as methyl but-2-enoyl group can also be used, downstream process of which can afford other synthetically interesting structures.
Trost
Barry M
BM
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA. bmtrost@stanford.edu
Xu
Jiayi
J
Schmidt
Thomas
T
D000438:Alcohols / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry; D000478:Alkylation; D000498:Allyl Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry*; D002384:Catalysis; D004987:Ethers / Q000138:chemical synthesis / Q000737:chemistry; D007659:Ketones / Q000138:chemical synthesis*; D008024:Ligands; D010165:Palladium / Q000737:chemistry; D013237:Stereoisomerism
D000438:Alcohols; D000475:Alkenes; D000498:Allyl Compounds; D002254:Carbonates; D004987:Ethers; D007659:Ketones; D008024:Ligands; D010165:Palladium