Synthesis, Characterisation, and Organocatalytic Activity of Chiral Tetrathiahelicene Diphosphine Oxides
Articolo
Data di Pubblicazione:
2014
Citazione:
Synthesis, Characterisation, and Organocatalytic Activity of Chiral Tetrathiahelicene Diphosphine Oxides / S. Cauteruccio, D. Dova, M. Benaglia, A. Genoni, M. Orlandi, E. Licandro. - In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY. - ISSN 1434-193X. - 2014:13(2014), pp. 2694-2702. [10.1002/ejoc.201301912]
Abstract:
Two new chiral tetrathia[7]helicene (7-TH) based tertiary phosphine oxides (±)-2b and (±)-2c, bearing two substituents on the phosphorus atoms with different steric and electronic properties, have been synthesised and fully characterised by means of analytical and spectroscopic techniques. The resolution of (±)-2a-c into their antipodes was accomplished by HPLC separation on a chiral stationary phase, and their chiroptical properties were investigated by CD spectroscopy. The behaviour of 2a-c as organocatalysts was assessed in representative reactions mediated by tri- or tetrachlorosilane. 7-TH-based phosphine oxides 2a and 2b promoted both ketoimine reduction and stereoselective carbon-carbon bond formation in good chemical yields and diastereoselectivity, albeit with low enantioselectivity, thus opening the way to the development of a novel class of enantiopure helical-based phosphorus organocatalysts. A novel class of tetrathia[7]helicene-based diphosphine oxides has been synthesised, and their catalytic behaviour as chiral helical phosphorus Lewis bases has been preliminary investigated in organocatalytic reactions.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Diastereoselectivity; Fused-ring systems; Helical structures; Organocatalysis; Phosphines
Elenco autori:
S. Cauteruccio, D. Dova, M. Benaglia, A. Genoni, M. Orlandi, E. Licandro
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