- Chemoenzymatic dynamic kinetic resolution of α-trifluoromethylated amines: Influence of substitutions on the reversed stereoselectivity
-
Enzymatic resolution of α-trifluoromethylated amines via kinetic resolution (KR), dynamic kinetic resolution (DKR) employing CALB-Pd/Al 2O3, and a one-pot sequential process of KR/DKR/KR was investigated comparatively for the first time. Although CALB-catalyzed KR of α-trifluoromethylated amines with substituents of methyl (1a), isopropyl (1c), phenyl (1d) and benzyl group (1e) can provide good stereoselectivity factors E from 31 to >200 respectively, DKR and sequential process of KR/DKR/KR possess better practical application potential because of the higher conversion (62%-84%) and the similar enantiomeric excesses (90%-99%). The enantiopreference and inversion for the α-trifluoromethylated amines displayed by CALB were observed and explained by docking modes. Namely, for 1,1,1-trifluoro-2-propylamine (1a), the product amide with R-configuration was obtained, and the enantiopreference was converted to S for the amines (1b-1e) with substituents larger than methyl group. The catalysts recycle, and scale-up experiments were demonstrated successfully. All these results indicated the high efficiency and green feature of this enzymatic process, and its application significance.
- Cheng, Guilin,Xia, Bo,Wu, Qi,Lin, Xianfu
-
p. 9820 - 9828
(2013/09/02)
-
- Discovery of novel HCV inhibitors: Synthesis and biological activity of 6-(indol-2-yl)pyridine-3-sulfonamides targeting hepatitis C virus NS4B
-
A novel series of 6-(indol-2-yl)pyridine-3-sulfonamides was prepared and evaluated for their ability to inhibit HCV RNA replication in the HCV replicon cell culture assay. Preliminary optimization of this series furnished compounds with low nanomolar potency against the HCV genotype 1b replicon. Among these, compound 8c has identified as a potent HCV replicon inhibitor (EC50 = 4 nM) with a selectivity index with respect to cellular GAPDH of more than 2500. Further, compound 8c had a good pharmacokinetic profile in rats with an IV half-life of 6 h and oral bioavailability (F) of 62%. Selection of HCV replicon resistance identified an amino acid substitution in HCV NS4B that confers resistance to these compounds. These compounds hold promise as a new chemotype with anti-HCV activity mediated through an underexploited viral target.
- Zhang, Xiaoyan,Zhang, Nanjing,Chen, Guangming,Turpoff, Anthony,Ren, Hongyu,Takasugi, James,Morrill, Christie,Zhu, Jin,Li, Chunshi,Lennox, William,Paget, Steven,Liu, Yalei,Almstead, Neil,George Njoroge,Gu, Zhengxian,Komatsu, Takashi,Clausen, Valerie,Espiritu, Christine,Graci, Jason,Colacino, Joseph,Lahser, Fred,Risher, Nicole,Weetall, Marla,Nomeir, Amin,Karp, Gary M.
-
p. 3947 - 3953
(2013/07/27)
-
- Fungicidal trifluoromethylalkylamino-triazolopyrimidines
-
An improved process for the preparation of (S)-1,1,1-trifluoroalkyl-2-amines of formula IIIA, STR1 where R1 is a C1-6 alkyl group, from the corresponding racemic mixture, which process includes treating 1 part by mole of the racemic mixture with approximately 0.3 to 0.7 part by mole of D-(-)-tartaric acid in the presence of an inert solvent.
- -
-
-
