10.1021/ja010789t.s001
Norio Shibata
Norio
Shibata
Emiko Suzuki
Emiko
Suzuki
Toru Asahi
Toru
Asahi
Motoo Shiro
Motoo
Shiro
Enantioselective Fluorination Mediated by Cinchona Alkaloid
Derivatives/Selectfluor Combinations: Reaction Scope and Structural
Information for <i>N</i>-Fluorocinchona Alkaloids
American Chemical Society
2001
chiral derivatizing reagents 3
DHQDA
combination
PYR
1 H NMR analyses
ee
DHQB
DHQD
Enantioselective Fluorination Mediated
fluoroammonium cinchona alkaloid tetrafluoroborates
DHQ
enantioselective fluorination
AQN
2001-06-30 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Enantioselective_Fluorination_Mediated_by_Cinchona_Alkaloid_Derivatives_Selectfluor_Combinations_Reaction_Scope_and_Structural_Information_for_i_N_i_-Fluorocinchona_Alkaloids/3634467
Cinchona-alkaloid/Selectfluor combinations efficiently fluorinate a variety of carbonyl compounds
in a highly enantioselective manner to furnish chiral α-fluorocarbonyl compounds. The DHQB/Selectfluor
combination is effective for the enantioselective fluorination of indanones and tetralones <b>1</b> in up to 91% ee.
The first enantioselective syntheses of chiral derivatizing reagents <b>3</b> was accomplished with high ee and in
high chemical yields by the DHQDA/Selectfluor combination. 3-Fluorooxindoles <b>7</b> were prepared with ee up
to 83% using the (DHQ)<sub>2</sub>AQN/Selectfluor or the (DHQD)<sub>2</sub>PYR/Selectfluor combination. Since the combinations
are conveniently prepared in situ from readily available reagents, the present system represents a practical
method for enantioselective fluorination. X-ray crystallography and <sup>1</sup>H NMR analyses of the cinchona alkaloids/Selectfluor combination have established that the species that mediate this novel reaction are <i>N</i>-fluoroammonium
cinchona alkaloid tetrafluoroborates, which adopt open conformations.