COORDINATED COMPOUNDS (3)

Author: PAREDES PEREZ PALOMA.
Year: 2006.
University: OVIEDO [www.uniovi.es].
Place of defense: FACULTAD DE QUIMICA.
Place of preparation: INSTITUTO UNIVERSITARIO DE QUIMICA ORGANOMETALICA ENRIQUE MOLES.

Summary: This paper describes the synthesis of complexes of iridium (I) and iridium (III) with ligands pybox enantiopuros and its first applications in asymmetric catalysis processes. In Chapter 1 describes the synthesis of the first complexes of iridium (I) with ligands R-pybox (R = iPr-, Ph- or in-pybox). Complexes cationic pentacoordinados [Go (? 2-C2H4) 2 (3-N, N, NR-pybox)] [Y] (Y = SbF6 or PF6) and tetracoordinados [Ir (CO) (3-N, N, NR- pybox)] [Y] (Y = SbF6 or PF6) have been synthesized from [Go (? Cl) (coe) 2] 2. Complex, cationic and neutral, mono-and bimetálicos, obtained by reaction of [Ir (? Cl) (coe) 2] 2 with pybox and various salts. It describes the preparation and characterization of the complex [IrI (3-N, N, N-iPr-pybox)], [Ir2 (? Cl) (3-N, N, NR-pybox) 2] [SbF6] and [(Go (3-N, N, N-iPr-pybox) (? Cl)) Ag] [SbF6]. In this chapter, is also studying reactivity of the complex [Go (? 2-C2H4) 2 (3-N, N, N-iPr-pybox)] [PF6] vs. alquinos. His reaction to DMAD generates complex [Go (? 2-MeO2CC? CCO2Me) 2 (3-N, N, N-iPr-pybox)] [PF6], whereas the reactions alquinos terminals, as propiolato ethyl or methyl lead to an unprecedented process of coupling between them and himself ligand pybox. In Chapter 2 describes the synthesis and reactivity of complex iridium (III) with ligands R-pybox (R = iPr-, Ph- or in-pybox). Complexes neutral [IrCl3 (3-N, N, NR-pybox)] have been prepared by reaction of [Ir (? Cl) (coe) 2] 2, pybox and Cl2 and cationic complexes reactions by oxidizing estereoselectivas on adding some complex iridium (I) -pybox described in the previous chapter. It describes the preparation of complex [IrI2L (3-N, N, NR-pybox)] [PF6] (L = C2H4, CO), [IrXR (? 2-C2H4) (3-N, N, NR-pybox) ] [PF6] or [IrXR (CO) (3-N, N, NR-pybox)] [PF6] (X = I, Cl, R = H, rent, acilo, alilo). Destaca la síntesis de complejos alilo e hidruro en condiciones suaves. The reaction of the complex hydride compared with ethylene (a process intramolecular) and against alquinos leads to the insertion of these processes on the link Ir-Hya the formation of new species dinucleares. In Chapter 3, evaluates the catalytic activity of many of the complex described in Chapters 1 and 2 in various catalytic processes. Specifically, it has studied its activity in the asymmetric synthesis of aldoles through a reduction aldólica reductive and the asymmetric reduction of ketones via two processes: hidrosililación and transfer of hydrogen. The catalysts tested are active and presented conversions and enantioselectividades varied. The reactions of reducing ketones by hydrogen transfer take place with high efficiency (conversion quantitative and excesses enantioméricos up from 77%) and represent the first examples of synthesis enantiopura of secondary alcohols using systems iridio-pybox as catalysts.