Studies in Asymmetric Catalysis: Lewis Base catalyzed/Lewis Acid Mediated Aldol Reactions of Ketone- and Amide Derived Nucleophiles

373 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Additionally, the use of the silicon tetrachloride---chiral phosphoramide system has proven a competent catalyst for highly selective vinylogous aldol reactions between dienolates derived from a variety of alpha,beta-unsaturated carbonyl compounds to aldehydes. These reactions provided high levels of gamma-site selectivity for a variety of substitution patterns on the dienyl unit. Both ketone- and morpholine amide-derived dienol ethers afforded excellent enantio- and diastereoselectivity in the addition to conjugated aldehydes. Although ketone-derived dienolate did not react with aliphatic aldehydes, amide-derived dienolates were found to undergo addition at reasonable rates affording high yields of vinylogous aldol product. The enantioselectivity achieved with the morpholine derived-dienolate in the addition to aliphatic aldehydes was the highest afforded to date with the silicon tetrachloride---chiral phosphoramide system. Furthermore, the ability to cleanly convert the morpholine amide to a methyl ketone was demonstrated.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD