Asymmetric Synthesis of 2H‐Azirines with a Tetrasubstituted Stereocenter by Enantioselective Ring Contraction of Isoxazoles. (12th December 2017)

• Record Type: Journal Article
• Authors: Okamoto, Kazuhiro; Nanya, Atsushi; Eguchi, Akira; Ohe, Kouichi
• Is Part Of: Angewandte Chemie. Volume 130:Number 4(2018)
• Page Start: 1051
• Page End: 1055
• Publication Date: 2017-12-12
• Subjects: 2H-Azirine -- Chirale Dienliganden -- Isoxazole -- Rhodiumkatalyse -- Stickstoffheterocyclen; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201710920
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Highly strained 2 H ‐azirines with a tetrasubstituted stereocenter were synthesized by the enantioselective isomerization of isoxazoles with a chiral diene–rhodium catalyst system. The effect of ligands and the coordination behavior support the proposed catalytic cycle in which the coordination site is fixed in favor of efficient enantiodiscrimination by a bulky substituent of the ligand. In silico studies also support the existence of a rhodium–imido complex as a key intermediate for enantiodiscrimination.