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A family of titanium (IV) alkoxo complexes with N,O and O,O chelating ligands. Crystal structure of [Ti(O-i-Pr)2{2-(−)-menthoxo-pyridine}2] |
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| Authors: | Yolanda Pérez Isabel Sierra Mariano Fajardo Isabel del Hierro |
| Institution: | a Departamento de Química Inorgánica y Analítica ESCET, Universidad Rey Juan Carlos, 28933 Móstoles, Madrid, Spain b Departamento de Química Inorgánica, Campus Universitario-Edificio de Farmacia, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain c Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Químicas, Campus Universitario, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain |
| Abstract: | In view of the wide applicability and versatility of titanium based Lewis acids in selective organic synthesis including asymmetric synthesis, we have synthesized a family of mono and polyatomic titanium derivatives. The polymetallic complexes prepared are bridged by pyridimine, quinone and triazine based ligands. The synthesis of {Ti(O-i-Pr)3(Oddbf)}2] (1), Ti(O-i-Pr)2(Oddbf)2] (2), {Ti(O-i-Pr)2(Oddbf)(OMent)}2] (3) (ddbfO = 2,3-dihydro-2,2-dimethyl-benzofuranoxo; MentO = (1R,2S,5R)-(−)-menthoxo), {Ti(O-i-Pr)3(OMenpy)}2] (4), Ti(O-i-Pr)2(OMenpy)2] (5) (MenpyO = (1S,2S,5R)-(−)-menthoxo-pyridine); {(Ti(OR)3)2L}n] (RO = isopropoxo, (1R,2S,5R)-(−)-menthoxo) (6-11) and {(Ti(O-i-Pr)3)3L}n] (12) was accomplished from a Lewis acid such as Ti(O-i-Pr)4, {Ti(O-i-Pr)3(OMent)}2] or Ti(OMent)4] and chelating ligands (ddbfOH = 2,3-dihydro-2,2-dimethyl-benzofuranol; MenpyOH = (1R,2S,5R)-(−)-5-methyl-2-isopropyl-1-(2′-pyridinyl)cyclohexan-1-ol; LH2 = 4,6-dihydroxy-2,5-diphenyl-pyrimidine, 2,4-dihydroxy-5,6-dimethyl-pyrimidine, 5,8-dihydroxy-1,4-napthoquinone, 2,5-dihydroxy-1,4-benzoquinone and LH3 = cyanuric acid) that provide a rigid framework for the metal centre. The molecular structure of 5 has been determined by single crystal X-ray diffraction studies. |
| Keywords: | Titanium (IV) complexes Chelating rigid ligands Asymmetric epoxidation X-ray structure determination |
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