Stereoselective Conjugate Addition-Enamination of α-Linear N-tert-Butanesulfinyl Ketimines with Nitroolefins

Abstract

N-Sulfinyl metalloenamines, generated by deprotonating α-linear N-tert-butanesulfinyl ketimines, reacted with nitroalkenes via stereoselective conjugate addition to give Michael adducts with opposite stereochemistry to that obtained using α-branched sulfinylketimines. In the presence of excess base (2.5 equiv t-BuOK), the adducts derived from α-linear ketimines were further stereoselectively deprotonated to afford the corresponding kinetically favorable N-sulfinyl (Z)-enamine derivatives in good yields with good stereoselectivities. A reaction model was proposed to rationalize the observed stereochemistry.

Key words

N-sulfinyl metalloenamines - conjugate addition - deprotonation - enamination - stereoselectivity

Publikationsverlauf

Eingereicht: 02. April 2022

Angenommen nach Revision: 12. April 2022

Artikel online veröffentlicht:
23. Mai 2022

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