Bis[2‐(oxazolinyl)phenolato]oxovanadium(IV) Complexes: Syntheses, Crystal Structures and Catalyses

Abstract

The syntheses and X-ray crystal structures of two chiral bis[2-(oxazolinyl)phenolato]-oxovanadium(IV) complexes gated. are reported. Their catalytic activity in oxidative transformations and C-C bond-forming reactions has been investi-(Hydroxypheny1)oxazolines serve as chelating units in microbial metal-transporting agents, which show high affinity and specificity for iron(III) [']. Various derivatives can readily be synthesized by a metal-catalyzed condensation reaction of hydroxybenzonitriles and 2-amino alcohols The molecular structures of vanadium complexes (S, S)-5 and (R,R)-6 were unambiguously established by X-ray crystal structure determinations. These studies also confirmed the absolute configurations. Full ORTEP plots are given in Figures 1 and 2["].In the complexes (S,S)-5 and (R,R)-6, two homochiral dianionic ligands are bound to the metal giving a syuarepyramidal coordination geometry around vanadium

Structural models for the reduced form of vanadate-dependent peroxidases: vanadyl complexes with bidentate chiral Schiff base ligands

“…Syntheses followed a procedure described by Bolm [18]. The Schiff base ligands were prepared by condensation of the carbonyl with the enantio-pure amine component in toluene, the complexes by reaction of the ligands with VO(acac) 2 in ethanol (1) or toluene (2), or with VOCl 2 (thf) 2 in toluene/THF (3) (THF ¼ tetrahydrofurane).…”

Coordination chemistry and applications of metal phenolates containing an oxazoline group

“…Floriani Stable vanadyl systems can also be produced (Bolm et al 1997, Hwang and Abu-Omar 1999, Melchior et al 1999, Kandasamy et al 2004) using sterically non-bulky PhoxH ligands such as achiral 2-(4′,4′-dimethyl-2′-oxazolinyl) phenol (Bolm et al 1997, Melchior et al 1999 or its enantio-pure mono-ethyl congener (Kandasamy et al 2004). (Bolm et al 1997, Melchior et al 1999, Kandasamy et al 2004.…”

“…Due to the importance of Group 4 complexes in polymerisation chemistry (vide infra), it is not surprising that complexes of Ti, Zr, and Hf have been examined for their binding properties with the PhoxH ligands (Cozzi (1) Brought to you by | University of Michigan Authenticated Download Date | 6/15/15 3:26 PM and Floriani 1995, , Bolm et al 1997, Melchior et al 1999, Bott et al 2005, Lee et al 2009). Floriani Stable vanadyl systems can also be produced (Bolm et al 1997, Hwang and Abu-Omar 1999, Melchior et al 1999, Kandasamy et al 2004) using sterically non-bulky PhoxH ligands such as achiral 2-(4′,4′-dimethyl-2′-oxazolinyl) phenol (Bolm et al 1997, Melchior et al 1999 or its enantio-pure mono-ethyl congener (Kandasamy et al 2004).…”

“…yield = 86%; (iii) Max. yield = 82% Zr (Bott et al 2005) R 2 Zr(20) 2 (R = Cl or alkyl) Ethylene polymerisation Up to 10 8 g polyethylene (mol bar h) -1 V (Bolm et al 1997;Melchior et al 1999) (i) Max. activity = 5.5 × 10 5 g (mol Ni·h) -1 ; (ii) Max.…”

Asymmetric reactions catalyzed by chiral titanium complexes

“…Bolm tried out the oxazoline-vanadium (IV) complex on the oxidation of prochiral sulfides, but failed with racemic sulfoxides. 13 These results prompted us to design some new oxazolines 5 with diverse substitutes and to explore them on the transformation process (Scheme 2).…”