1. TetraPh-Tol-BITIOPO: a new atropisomeric 3,3'-bithiophene based phosphine oxide as an organocatalyst in Lewis base-catalyzed Lewis acid mediated reactions
- Author
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Abbinante Vincenzo Mirco, Benincori Tiziana, Cirilli Roberto, Pierini Marco, Rossi Sergio, and Benaglia Maurizio
- Subjects
Phosphine oxide ,chiral phosphine oxide ,Lewis base-catalyzed Lewis acid mediated reactions ,atropisomeric organocatalyst ,010405 organic chemistry ,organic chemicals ,Organic Chemistry ,Absolute configuration ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Medicinal chemistry ,0104 chemical sciences ,Catalysis ,Chiral column chromatography ,chemistry.chemical_compound ,chemistry ,Aldol reaction ,Allyltrichlorosilane ,Lewis acids and bases ,Physical and Theoretical Chemistry ,Enantiomeric excess - Abstract
A new chiral phosphine oxide based on a 3,3'-bithiophene scaffold (TetraPh-Tol-BITIOPO) was synthesized, fully characterized and separated into antipodes through chiral HPLC. This new compound was successfully employed as an organocatalyst in Lewis base-catalyzed Lewis acid mediated reactions involving trichlorosilyl compounds. The new atropisomeric catalyst was able to promote the allylation of aldehydes with allyltrichlorosilane in up to 98% yield and up to 96% enantiomeric excess (ee), and the direct aldol reaction to afford β-hydroxy ketones and β-hydroxy thioesters, with good chemical yields and modest stereochemical efficiency. Computational studies helped to elucidate and to rationalize the stereochemical outcome of the reactions catalyzed by TetraPh-Tol-BITIOPO that was found to favour the formation of the isomer with an opposite absolute configuration in comparison with the products obtained with the previously reported 3,3'-bithiophene-based catalyst.
- Published
- 2019