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Direct Enantioselective α‐Allylation of Unfunctionalized Cyclic Ketones with Alkynes through Pd‐Amine Cooperative Catalysis
Author(s) -
Lee Jin Tu Danence,
Zhao Yu
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201802273
Subject(s) - enantioselective synthesis , chemistry , catalysis , amine gas treating , organic chemistry , synergistic catalysis , palladium , combinatorial chemistry
The first direct enantioselective α‐allylation of unfunctionalized cyclic ketones using alkynes as an economical choice of reagent is reported. This transformation uses a simple procedure with commercially available palladium, chiral bisphosphine ligand and chiral amine catalysts, and affords valuable ketones with a α‐tertiary stereocenter in good to high enantiopurity. In this transformation, a chiral palladium complex containing the ( S )‐DIFLUORPHOS ligand catalyzes the isomerization of alkynes into an electrophilic allylpalladium species, which is attacked by the enamine generated in situ from the condensation of ( R )‐prolinol with the ketone substrate.