Two Stereoinduction Events in One C−H Activation Step: A Route towards Terphenyl Ligands with Two Atropisomeric Axes. (13th March 2018)

• Record Type: Journal Article
• Authors: Dherbassy, Quentin; Djukic, Jean‐Pierre; Wencel‐Delord, Joanna; Colobert, Françoise
• Is Part Of: Angewandte Chemie. Volume 130:Number 17(2018)
• Page Start: 4758
• Page End: 4762
• Publication Date: 2018-03-13
• Subjects: Asymmetrische C-H-Aktivierung -- Atropisomerie -- Axialchiralität -- Chirale Liganden -- Sulfoxide; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201801130
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Herein we disclose the synthesis of original chiral scaffolds— ortho ‐orientated terphenyls presenting two atropisomeric Ar–Ar axes. These unusual structures were built up by using the C−H activation approach, and remarkably, both chiral axes were controlled with excellent stereoselectivity in a single transformation. During the reaction, not only does atroposelective functionalization of a biaryl precursor occur to establish one stereogenic axis, but an unprecedented atropo‐stereoselective C−H arylation also takes place to generate the second stereogenic element. These enantiomerically pure ortho ‐terphenyls show an original tridimensional structure and thus constitute a unique foundation for building up a library of enantiomerically pure bidentate ligands, such as the new ligands S/N‐Biax and diphosphine BiaxPhos. Abstract : Muschel‐Ligand : Ungewöhnliche chirale Strukturen – ortho ‐orientierte Terphenyle mit zwei atropisomeren Ar‐Ar‐Achsen – wurden durch C‐H‐Aktivierung hergestellt. Beide stereogenen Achsen wurden mit exzellenter Stereokontrolle in einer einzigen Umwandlung erzeugt (siehe Schema). Die chiralen ortho ‐Terphenyl‐Produkte bilden eine neuartige dreidimensionale Architektur für zweizähnige Liganden.