Ni(II)-Catalyzed Enantioselective Addition of Thiols and Thiophenols to Pyrazolinone-Derived Ketimines
Mengxin Kan1, Guiyun Gao1, Xinyu Hou1
1College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin300350, China.
Abstract:
Enantioselective additions of thiols and thiophenols to pyrazolinone-derived ketimines were realized using a Ni(II) complex bearing a tridentate binaphthyl-proline-imidazoline-based chiral ligand as the catalyst. The well-defined confined environment of the catalyst enabled the stereofacial selective activation of the electrophiles, and the products were obtained in up to 99% yield with 99% ee. The reactions featured low catalyst loading, mild conditions, broad substrate scope, and gram-scale utility. X-ray diffraction experiments confirmed both the configuration of the C═N double bond and the absolute configuration of the products, and stereofacial selection of the reactions was deduced accordingly.
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