119561-23-8Relevant articles and documents
New synthetic access to 3-fluoroalkyl-5-pyrazolecarboxylates and carboxylic acids
Herrera, Alberto Gómez,Schmitt, Etienne,Panossian, Armen,Vors, Jean-Pierre,Pazenok, Sergii,Leroux, Frédéric R.
, p. 17 - 23 (2018/08/10)
A novel process for preparing 3-fluoroalkyl-5-pyrazolecarboxylates and carboxylic acids is hereby presented. Easily accesible α-fluorinated ketimines were condensed with oxalyl monochloride derivatives, and the obtained vinamides underwent acid-catalyzed cyclization with substituted hydrazines. This highly efficient protocol can also be used for non-fluorinated C-3 and C-5 substituents.
PROCESS FOR PREPARING 3,5-BIS(HALOALKYL)PYRAZOLE DERIVATIVES FROM α,α-DIHALOAMINES AND KETIMINES
-
Page/Page column 17, (2015/11/24)
Process for preparine3,5-bis(haloalkyl)pyrazolederivatives from a,a-dihaloamines and ketimines The present invention relates to a novel process for preparing 3,5-bis(haloalkyl)pyrazole derivatives from a,a-dihaloamines and ketimines. Intermedaites used in the process are also claimed.
Chemoenzymatic dynamic kinetic resolution of α-trifluoromethylated amines: Influence of substitutions on the reversed stereoselectivity
Cheng, Guilin,Xia, Bo,Wu, Qi,Lin, Xianfu
, p. 9820 - 9828 (2013/09/02)
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.