An efficient protocol for kinetic resolution of tertiary alcohols has been developed through an unprecedented asymmetric enamide‐imine tautomerism process enabled by chiral phosphoric acid catalysis. A broad range of racemic 2‐arylsulfonamido tertiary allyl alcohols could be kinetically resolved with excellent kinetic resolution performances (with s‐factor up to >200). This method is particularly effective for a series of 1,1‐dialkyl substituted allyl alcohols, which produced chiral tertiary alcohols that would be difficult to access via other asymmetric methods. Facile and versatile transformations of the chiral α‐hydroxy imine and enamide products, especially the efficient stereodivergent synthesis of all four stereoisomers of β‐amino tertiary alcohols using one enantiomer of the catalyst, demonstrated the value of this kinetic resolution method.
A novel asymmetric synthesis of dihydropyridinones with vicinal quaternary stereocenters has been realized by asymmetric aza-Diels−Alder reactions of 3-amido allylic alcohols with oxazolones enabled by chiral phosphoric acid catalysis. A series of aryl/alkyl-and alkyl/alkyl-disubstituted 3-amido allylic tertiary alcohols and 4-substituted oxazolones could be well tolerated in these reactions, producing dihydropyridinones with excellent diastereoselectivities and high enantioselectivities. Mechanistic study and control experiments were performed to shed light on the reaction mechanism, in which a configurationally defined β,β-disubstituted α,β-unsaturated N−H ketimine was proposed as the key intermediate.
An efficient protocol for kinetic resolution of tertiary alcohols has been developed through an unprecedented asymmetric enamide-imine tautomerism process enabled by chiral phosphoric acid catalysis.Abroad range of racemic 2arylsulfonamido tertiary allyl alcohols could be kinetically resolved with excellent kinetic resolution performances (with sfactor up to > 200). This method is particularly effective for as eries of 1,1-dialkyl substituted allyl alcohols,w hichp roduced chiral tertiary alcohols that would be difficult to access via other asymmetric methods.F acile and versatile transformations of the chiral a-hydroxy imine and enamide products,e specially the efficient stereodivergent synthesis of all four stereoisomers of b-amino tertiary alcohols using one enantiomer of the catalyst, demonstrated the value of this kinetic resolution method.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.