The first organocatalytic enantioselective Streckersynthesis of α-quaternary α-trifluoromethylated amino acids has been developed. Employing Takemoto’s thiourea catalyst the nucleophilic addition of trimethylsilyl cyanide to trifluoromethyl ketimines affords α-amino nitriles in good to excellent yields (50–99%) and very good enantioselectivities (ee=83–95%). The enantiopure amino nitriles can be obtained
Anionic-Anionic Asymmetric Tandem Reactions: One-Pot Synthesis of Optically Pure Fluorinated Indolines from 2-<i>p</i>-Tolylsulfinyl Alkylbenzenes
作者:José Luis García Ruano、José Alemán、Silvia Catalán、Vanesa Marcos、Silvia Monteagudo、Alejandro Parra、Carlos del Pozo、Santos Fustero
DOI:10.1002/anie.200802885
日期:2008.9.29
Diastereodivergent Synthesis of Fluorinated Cyclic β<sup>3</sup>-Amino Acid Derivatives
作者:Isabel Aparici、Marta Guerola、Clemens Dialer、Antonio Simón-Fuentes、María Sánchez-Roselló、Carlos del Pozo、Santos Fustero
DOI:10.1021/acs.orglett.5b02759
日期:2015.11.6
The ability of 2-p-tolylbenzyl carbanions to behave as a source of chiral benzylic nucleophiles has been shown in its reaction with fluorinated imines. The process takes place with high levels of stereocontrol, rendering the corresponding amines as single diastereoisomers. Subsequent cross-metathesis followed by intramolecular aza-Michael reaction makes the synthesis of fluorinated homoproline derivatives bearing three stereogenic centers possible. Furthermore, the selectivity of the cyclization process can easily be tuned up in a diastereodivergent manner simply by changing the reaction conditions.