The more gold - the more enantioselective

• Verfasst von: Rodríguez Broncano, Lara-Isabel [VerfasserIn]
• Verfasst von: Roth, Torsten [VerfasserIn]
• Verfasst von: Lloret Fillol, Julio [VerfasserIn]
• Verfasst von: Wadepohl, Hubert [VerfasserIn]
• Verfasst von: Gade, Lutz H. [VerfasserIn]
• Titel: The more gold - the more enantioselective
• Titelzusatz: cyclohydroaminations of γ-allenyl sulfonamides with mono-, bis-, and trisphospholane gold(I) catalysts ; dedicated to Professor Peter Hofmann on the occasion of his 65th birthday
• Mitwirkende: Hofmann, Peter [GefeierteR]
• Verf.angabe: Lara-Isabel Rodríguez, Torsten Roth, Julio Lloret Fillol, Hubert Wadepohl, and Lutz H. Gade
• Umfang: 8 S.
• Fussnoten: Gesehen am 20.07.2018
• Titel Quelle: Enthalten in: Chemistry - a European journal
• Jahr Quelle: 2012
• Band/Heft Quelle: 18(2012), 12, S. 3721-3728
• ISSN Quelle: 1521-3765
• DOI: doi:10.1002/chem.201103140
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1577807790

Abstract

A series of chiral mono-, di-, and trinuclear gold(I) complexes have been prepared and used as precatalysts in the asymmetric cyclohydroamination of N-protected γ-allenyl sulfonamides. The stereodirecting ligands were mono-, di-, and tridentate 2,5-diphenylphospholanes, which possessed C1, C2, and C3 symmetry, respectively, thereby rendering the catalytic sites in the di- and trinuclear complexes symmetry equivalent. The C3-symmetric trinuclear complex displayed the highest activity and enantioselectivity (up to 95 % ee), whilst its mono- and dinuclear counterparts exhibited considerably lower enantioselectivities and activities. A similar trend was observed in a series of mono-, di-, and trinuclear 2,5-dimethylphospholane gold(I) complexes. Aurophilic interactions were established from the solid-state structures of the trinuclear gold(I) complexes, thereby raising the question as to whether these secondary forces were responsible for the different catalytic behavior observed.