Optically active bis(aminophenols) and their metal complexes

• Published in: Dalton transactions : an international journal of inorganic chemistry 2023-09, Vol.52 (37), p.1329-1333
• Main Authors: Carbonel, Halen, Mikulski, Timothy D, Nugraha, Kahargyan, Johnston, James, Wang, Yichun, Brown, Seth N
• Format: Article
• Language: English
• Subjects: Aminophenol; Chromophores; Coordination compounds; Diamines; Dichroism; Optical activity; Osmium; Palladium; Refluxing; Spectra; Toluene
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d3dt02436a

Optically active C 2 -symmetric bis(aminophenols) based on ( R )-2,2′-diaminobinaphthyl (BiniqH 4 ) and ( R , R )-2,3-butanediyldianthranilate (BdanH 4 ) have been prepared by condensation of the diamines with 3,5-di- tert -butylcatechol. Group 10 bis(iminosemiquinone) complexes ( R )-(Biniq)M (M = Pd, Pt) and ( C , R , R )-(Bdan)Pd have been prepared by oxidatively metalating the corresponding ligands. In ( R )-(Biniq)M, the C 2 axis passes through the approximate square plane of the bis(iminosemiquinone)metal core, while in ( C , R , R )-(Bdan)Pd the C 2 axis is perpendicular to this plane. In the latter compound, the ( R , R )-butanediyl strap binds selectively over one enantioface of the metal complex in a conformation where the methyl groups are anti to one another. Osmium oxo complexes with the intrinsically chiral OsO(amidophenoxide) 2 chromophore are obtained by metalation of OsO(OCH 2 CH 2 O) 2 with ( R , R )-BdanH 4 . Both the ( A , R , R ) and ( C , R , R ) diastereomers can be observed, with metalation in refluxing toluene selectively giving the latter isomer. The electronic structures of the complexes are illuminated by the circular dichroism spectra, in conjuction with the optical spectra and TDDFT calculations. Optically active bis(aminophenols) are prepared and stereoselectively metalated to form palladium and platinum bis(iminosemiquinone) and oxoosmium bis(amidophenoxide) complexes.