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]
2006; Elsevier BV; Volume: 360; Issue: 2 Linguagem: Inglês
10.1016/j.ica.2006.08.003
ISSN1873-3255
AutoresYolanda Pérez, Sonia Morante‐Zarcero, Isabel Sierra, Pilar Gómez‐Sal, Mariano Fajardo, Antonío Otero, Isabel del Hierro,
Tópico(s)Chemical Synthesis and Reactions
ResumoIn 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.
Referência(s)