Phosphine‐Catalyzed β‐Selective Conjugate Addition of α‐Fluoro‐β‐ketoamides to Allenic Esters

A Strategy for the β‐selective conjugate addition of α‐fluoro‐β‐ketoamides to allenic esters has been developed via phosphine catalysis. This protocol exhibits a broad substrate scope, and a wide range of compounds bearing fluorinated quaternary carbon center was obtained in good to excellent yields. This protocol allows the use of γ‐substituted allenic esters to furnish the products with exclusive β‐selectivity. A strategy for the β‐selective conjugate addition of α‐fluoro‐β‐ketoamides to allenic esters has been developed via phosphine catalysis and demonstrated for a wide range of ketoamides and allenoate substrates.