A diastereo- and enantioselective propargylic substitution reaction between propargylic carbonates and α-substituted nitroacetates catalyzed by a Cu-pybox complex is described. This method allows the preparation of a series of non-proteinogenic quaternary α-aminoacid precursors featuring two contiguous stereogenic centers and a terminal alkyne moiety in high yields with good to excellent diastereo-
A quaternary ammonium salt represented by formula (
5
)
(wherein R
1
represents an alkyl group having 1 to 4 carbon atoms, R
2
represents an alkyl group having 1 to 10 carbon atoms, R
3
represents an alkyl group having 1 to 10 carbon atoms that is optionally substituted with one or more phenyl groups; or a phenyl group that optionally has one or more groups selected from the group consisting of alkyl groups having 1 to 10 carbon atoms and a trifluoromethyl group, R
4
represents an alkyl group having 1 to 4 carbon atoms, R
5
represents an alkyl group having 1 to 10 carbon atoms, C* represents an asymmetric carbon atom, and X
−
represents a halide ion) can be used as a catalyst having good stability under basic conditions.
McKenzie; Mills; Myles, Chemische Berichte, 1930, vol. 63, p. 904,910
作者:McKenzie、Mills、Myles
DOI:——
日期:——
US9259723B2
申请人:——
公开号:US9259723B2
公开(公告)日:2016-02-16
Design and Evaluation of Inclusion Resolutions, Based on Readily Available Host Compounds
作者:Simona Müller、Marcel Cyrus Afraz、René de Gelder、Gerry J. A. Ariaans、Bernard Kaptein、Quirinus B. Broxterman、Alle Bruggink
DOI:10.1002/ejoc.200400613
日期:2005.3
of enantiomers through selective crystallisation of diastereomeric inclusioncompounds can extend the scope of traditional racemate resolution beyond salt forming compounds. To assess the practical value of this approach the literature was carefully screened and promising results were checked. Also an extensive range of new inclusion hosts suitable for resolution processes, derived from simple hydroxyand