0000000001320436
AUTHOR
Anton Axelsson
Asymmetric Synthesis of Dihydropyranones with Three Contiguous Stereocenters by an NHC‐Catalyzed Kinetic Resolution
An oxidative NHC-catalyzed kinetic resolution (KR) of racemic mixtures is presented. The developed reaction furnishes tricyclic dihydropyranones with three contiguous stereocenters in excellent dia- and enantioselectivity, with good-to-moderate yields. Mechanistic studies indicate that the rate-determining step of the reaction is the formation of the Breslow intermediate, while the selectivity determining step occurs later in the mechanism. The presented methodology enables rapid synthesis of complex structures in a single step. peerReviewed
Asymmetric Synthesis of Dihydropyranones with Three Contiguous Stereocenters by an NHC‐Catalyzed Kinetic Resolution
An oxidative NHC-catalyzed kinetic resolution (KR) of racemic mixtures is presented. The developed reaction furnishes tricyclic dihydropyranones with three contiguous stereocenters in excellent dia- and enantioselectivity, with good-to-moderate yields. Mechanistic studies indicate that the rate-determining step of the reaction is the formation of the Breslow intermediate, while the selectivity determining step occurs later in the mechanism. The presented methodology enables rapid synthesis of complex structures in a single step.
Ionic liquids as precatalysts in the highly stereoselective conjugate addition of α,β-unsaturated aldehydes to chalcones.
Imidazolium-based ionic liquids (ILs) serve both as recyclable reaction media and as precatalysts for the N-heterocyclic carbene-catalyzed conjugate addition of α,β-unsaturated aldehydes to chalcones. The reaction produces a broad scope of 1,6-ketoesters incorporating an anti-diphenyl moiety in high yields and with high stereoselectivity. In recycling experiments, the IL can be reused up to five times with retained reactivity and selectivity. Moreover, the 1,6-ketoesters form self-assembled organogels in aliphatic hydrocarbons. The reaction protocol is robust, easily operated, scalable and highly functionalized compounds can be obtained from inexpensive and readily accessible starting mater…
CCDC 1010853: Experimental Crystal Structure Determination
Related Article: Linda Ta, Anton Axelsson, Joachim Bijl, Matti Haukka, Henrik Sundén|2014|Chem.-Eur.J.|20|13889|doi:10.1002/chem.201404288