0000000001309187
AUTHOR
Tõnis Kanger
CaCl2, Bisoxazoline, and Malonate: A Protocol for an Asymmetric Michael Reaction
A mild protocol for the asymmetric Michael addition of dimethyl malonate to various α,β-unsaturated carbonyl compounds was developed. The salient feature of this methodology is that a cheap and environmentally friendly Lewis acid, CaCl2, was used as a catalyst. An aminoindanol- and pyridine-derived ligand provided in the presence of CaCl2 Michael adducts in moderate to high enantioselectivities. The scope of the reaction was demonstrated.
Synthesis and Characterisation of Chiral Triazole-Based Halogen-Bond Donors: Halogen Bonds in the Solid State and in Solution
A general platform for the synthesis of various chiral halogen-bond (XB) donors based on the triazole core and the characterisation of factors that influence the strength of the halogen bond in the solid state and in solution are reported. The characterisation of XB donors in the solid state by X-ray crystallography and in solution by 1H NMR titration can be used to aid the design of new XB donors. We describe the first example of a XB between iodotriazoles and thioureas in solution. In addition, the enantiodiscrimination of acceptors in solution through halogen-bond participation is described.
Asymmetric Organocatalytic Wittig [2,3]-Rearrangement of Oxindoles
A highly enantioselective organocatalytic [2,3]-rearrangement of oxindole derivatives is presented. The reaction was catalyzed by squaramide, and this provides access to 3-hydroxy 3-substituted oxindoles in high enantiomeric purities.
CCDC 1056977: Experimental Crystal Structure Determination
Related Article: Kristin Lippur , Sandra Kaabel , Ivar Järving , Kari Rissanen , and Tõnis Kanger|2015|J.Org.Chem.|80|6336|doi:10.1021/acs.joc.5b00769
CCDC 1447017: Experimental Crystal Structure Determination
Related Article: Maksim Ošeka, Mariliis Kimm, Sandra Kaabel, Ivar Järving, Kari Rissanen, and Tõnis Kanger|2016|Org.Lett.|18|1358|doi:10.1021/acs.orglett.6b00291
CCDC 1447018: Experimental Crystal Structure Determination
Related Article: Maksim Ošeka, Mariliis Kimm, Sandra Kaabel, Ivar Järving, Kari Rissanen, and Tõnis Kanger|2016|Org.Lett.|18|1358|doi:10.1021/acs.orglett.6b00291