Origin of the chemical stability of phosphine‐phosphoramidites: structural study of an UPPhos‐type crystal and application of UPPhos in the asymmetric hydrogenation of imines. Issue 8 (25th July 2017)

• Record Type: Journal Article
• Authors: Balogh, Szabolcs; Farkas, Gergely; Holczbauer, Tamás; Bakos, József
• Is Part Of: Acta crystallographica. Volume 73:Issue 8(2017)
• Page Start: 632
• Page End: 637
• Publication Date: 2017-07-25
• Subjects: phosphine–phosphoramidite -- through‐space coupling -- PPA -- iridium‐catalyzed hydrogenation -- crystal structure -- computational chemistry -- DFT -- asymmetric catalytic reaction; Crystallography -- Periodicals; Crystals -- Periodicals; 548.3
• DOI: 10.1107/S2053229617010403
• Languages: English
• ISSNs: 2053-2296

Abstract

Abstract : Structure elucidation of a single crystal of a new phosphine–phosphoramidite (PPA) revealed unique features which might have a significant effect on the excellent chemical stability of this type of molecule. The conformation of the molecule provides an optimal chelating structure. Abstract : Phosphine–phosphoramidites (PPAs) are heterobidentate ligands that have been developed in the last two decades and have been used successfully in asymmetric catalytic reactions. A single crystal of the PPA (11b S )‐ N ‐[(2 S, 4 S )‐4‐(diphenylphosphanyl)pentan‐2‐yl]‐ N ‐methyldinaphtho[2, 1‐ d :1′, 2′‐ f ][1, 3, 2]dioxaphosphepin‐4‐amine, C38 H35 NO2 P2, was prepared and structurally characterized by single‐crystal X‐ray diffraction and density functional theory (DFT) calculations. Structure elucidation revealed unique features which might have a significant effect in the excellent chemical stability of this type of molecule. The conformation of the molecule provides an optimal chelating structure. Iridium complexes of UPPhos were found to be efficient catalysts in the asymmetric hydrogenation of imines {UPPhos is (11b S )‐ N ‐[(2 S, 4 S )‐4‐(diphenylphosphanyl)pentan‐2‐yl]‐ N ‐(propan‐2‐yl)dinaphtho[2, 1‐ d :1′, 2′‐ f ][1, 3, 2]dioxaphosphepin‐4‐amine}.