Catalytic asymmetric synthesis of trans-configured beta-lactones: cooperation of Lewis acid and ion pair catalysis.
The development of the first trans-selective catalytic asymmetric [2+2] cyclocondensation of acyl halides with aliphatic aldehydes furnishing 3,4-disubstituted beta-lactones is described. This work made use of a new strategy within the context of asymmetric dual activation catalysis: it combines the concepts of Lewis acid and organic aprotic ion pair catalysis in a single catalyst system. The methodology could also be applied to aromatic aldehydes and offers broad applicability (29 examples). The utility was further demonstrated by nucleophilic ring-opening reactions that provide highly enantiomerically enriched anti-aldol products.
Kull
Thomas
T
ETH Zürich, Laboratory of Organic Chemistry, Wolfgang-Pauli-Str. 10, 8093 Zürich, Switzerland.
Cabrera
José
J
Peters
René
R
D000143:Acids / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D006846:Hydrocarbons, Halogenated / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
D000143:Acids; D000447:Aldehydes; D006846:Hydrocarbons, Halogenated; D007783:Lactones; C116609:3-hydroxybutanal