Enantiocontrol by assembled attractive interactions in copper-catalyzed asymmetric direct alkynylation of alpha-ketoesters with terminal alkynes: OH center dot center dot center dot O/sp(3)-CH center dot center dot center dot O two-point hydrogen bonding combined with dispersive attractions

Copper-catalyzed asymmetric direct alkynylation of alpha-ketoesters with terminal alkynes with chiral prolinol-phosphine ligands, most preferably (alpha R, 2S)-1-(2-dicyclohexylphosphinobenzyl)-alpha-neopentyl-2-pyrrolidinemethanol, afforded various enantioenriched chiral propargylic tertiary alcoho...

Full description

Saved in:
Bibliographic Details
Published inChemical science (Cambridge) Vol. 9; no. 14; pp. 3484 - 3493
Main Authors Schwarzer, Martin C., Fujioka, Akane, Ishii, Takaoki, Ohmiya, Hirohisa, Mori, Seiji, Sawamura, Masaya
Format Journal Article
LanguageEnglish
Published CAMBRIDGE Royal Soc Chemistry 14.04.2018
Subjects
Chemistry
Chemistry, Multidisciplinary
Physical Sciences
Science & Technology
PATH
RHODIUM(III) COMPLEXES
DOT-O INTERACTION
LIGANDS
APPROXIMATION
ZETA VALENCE QUALITY
BASIS-SETS
ALDEHYDES
ENANTIOSELECTIVE ADDITION
C-H
Online AccessGet full text

Cover

More Information
Summary:Copper-catalyzed asymmetric direct alkynylation of alpha-ketoesters with terminal alkynes with chiral prolinol-phosphine ligands, most preferably (alpha R, 2S)-1-(2-dicyclohexylphosphinobenzyl)-alpha-neopentyl-2-pyrrolidinemethanol, afforded various enantioenriched chiral propargylic tertiary alcohols. Quantumchemical calculations using the BP86 density functional including Grimme's empirical dispersion correction [DF-BP86-D3(BJ)-PCM(tBuOH)/TZVPP//DF-BP86-D3(BJ)/SVP] show the occurrence of OH center dot center dot center dot O/sp(3)-CH center dot center dot center dot O two-point hydrogen bonding between the chiral ligand and the carbonyl group of the ketoester in the stereo-determining transition states. Combined with the hydrogen-bonding interactions orienting the ketoester substrate, dispersive attractions between the chiral ligand (P-cyclohexyl groups) and the ketoester in the favored transition states, rather than steric repulsions in the disfavored transition state explain the enantioselectivity of the asymmetric copper catalysis.
ISSN:2041-6520
2041-6539
DOI:10.1039/c8sc00527c