Stereoselective Allylic Alkylations of Amino Ketones and Their Application in the Synthesis of Highly Functionalized Piperidines

Abstract

Chelated ketone enolates are excellent nucleophiles for allylic alkylations. Electron‐withdrawing groups on the allyl moiety allow subsequent intramolecular Michael additions giving rise to piperidines with up to five stereogenic centers.

The Allylic Alkylation of Ketone Enolates

“…Recently, this method was extended to allylic substrates bearing electron withdrawing groups like ester or nitrile groups, allowing subsequent cyclizations via 1,4‐addition [52] . The resulting ketones 7 were subjected to a sequence of ketone reduction, N ‐deprotection and Michael‐type addition furnishing highly substituted piperidines and homopipecolic acid derivatives, respectively (Scheme 33).…”

Total Synthesis of Moiramide B Using an Allylic Alkylation Approach

“…9 Recently, we also reported the stereoselective Pd-catalyzed allylic alkylation of chiral aminoketones A , where the stereogenic center at the α-position controls the formation of the zinc-chelated ketone enolate B and its stereoselective allylation (Scheme 1 A). 10…”