- Photoredox-catalyzed deoxyfluorination of activated alcohols with Selectfluor
-
Herein we disclose a deoxyfluorination of alcohols with an electrophilic fluorine source via visible-light photoredox catalysis. This radical-mediated C–F coupling is capable of fluorinating secondary and tertiary alcohols efficiently, complementing previously reported nucleophilic deoxyfluorination protocols.
- González-Esguevillas, María,Miró, Javier,Jeffrey, Jenna L.,MacMillan, David W.C.
-
p. 4222 - 4227
(2019/06/13)
-
- PROCESS FOR PRODUCTION OF OPTICALLY ACTIVE FLUOROPROLINE DERIVATIVE
-
A process for producing an optically active fluoroproline derivative represented by the general formula (2) by fluorinating an optically active hydroxyproline derivative represented by the general formula (1). The process comprises adding N-(2-chloro-1,1,2-trifluoroethyl) diethylamine or N-(1,1,2,3,3,3-hexafluoropropyl) diethylamine which is inexpensive and easy to handle to an aprotic nonpolar organic solvent at a temperature of 10?C or lower and then fluorinating the compound at a temperature ranging from 10 to 50?C. This process enables to produce an optically active fluoroproline derivative represented by the general formula (2) in which the configuration at position-4 of a compound represented by the general formula (1) is inverted, in a high purity with reduced by-product production. (1) (2) wherein R1 represents a substituted or unsubstituted alkyl or aryl group; R2 represents a substituted or unsubstituted alkyl, aryl, alkylcarbonyl, alkoxycarbonyl, arylcarbonyl or aryloxycarbonyl group; and an asterisk (*) denotes an asymmetric carbon.
- -
-
Page/Page column 10-11; 12-13
(2008/06/13)
-
- Practical synthesis of Boc and Fmoc protected 4-fluoro and 4-difluoroprolines from trans-4-hydroxyproline
-
Boc-cis-4-fluoro-L-proline and 4-difluoro-L-proline, usable in classical peptide synthesis, were obtained in respectively 71% (3 steps) and 65% (4 steps) overall yields from the readily available trans-4-hydroxy-L-proline methyl ester. The corresponding fluorinated trans-isomer was isolated in 24% yield (5 steps). Transformation of Boc-protected compounds to their Fmoc-equivalents was performed in high yields.
- Demange, Luc,Menez, Andre,Dugave, Christophe
-
p. 1169 - 1172
(2007/10/03)
-