Catalytic Asymmetric Synthesis of N‐Chiral Amine Oxides. Issue 42 (6th October 2016)

• Record Type: Journal Article
• Authors: Bhadra, Sukalyan; Yamamoto, Hisashi
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 42(2016)
• Page Start: 13043
• Page End: 13046
• Publication Date: 2016-10-06
• Subjects: asymmetric catalysis -- dynamic kinetic resolution -- homogeneous catalysis -- nitrogen oxides -- titanium; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201606354
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Direct asymmetric synthesis of N ‐chiral amine oxides was accomplished (up to 91:9 e.r.) by means of a bimetallic titanium catalyst. A hydroxy group situated at the γ‐position of the N stereocenter enables the desired N‐oxidation through dynamic kinetic resolution of the trivalent amine substrates. The method was further extended to the kinetic resolution of racemic γ‐amino alcohols with a preexisting stereocenter, giving an important class of enantioenriched (up to 99.9:0.1 e.r.) building blocks that are otherwise difficult to synthesize. Abstract : One‐sided : An asymmetric synthesis of N‐chiral amine oxides was developed that proceeds via dynamic kinetic resolution of unsymmetrical γ‐hydroxy tertiary amines. A binuclear titanium complex enables the desired hydroxy‐directed N‐oxidation process. The concept was further expanded to the kinetic resolution of racemic γ‐amino alcohols with a preexisting stereocenter.