Asymmetric aza-Morita–Baylis–Hillman reactions of chiral N-phosphonyl imines with acrylates via GAP chemistry/technology?

Organic & Biomolecular Chemistry Pub Date: 2016-05-23 DOI: 10.1039/C6OB00847J

Abstract

Chiral N-phosphonyl imines have been proven to be efficient electrophilic acceptors for asymmetric aza-Morita–Baylis–Hillman (aza-MBH) reactions with acrylates under convenient conditions. Thirty examples of β-amino acrylates were generated in high yields (up to 99.4%) and diastereoselectivity (up to >99?:?1 dr) in an atom-economical fashion. The synthesis was proved to follow the GAP (group-assisted purification) chemistry, i.e., the pure products can be obtained simply by washing the crude products with hexane/ethyl acetate (v/v, 10/1) without the use of chromatography or recrystallization. DFT calculations were also conducted to support an asymmetric induction model accounting for high diastereoselectivity.

Graphical abstract: Asymmetric aza-Morita–Baylis–Hillman reactions of chiral N-phosphonyl imines with acrylates via GAP chemistry/technology
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