Synthesis of CF3-bearing pyrrolidines by hydrogenation of trifluoroacetylated pyrrole derivatives

• Published in: Journal of fluorine chemistry Vol. 180; pp. 257 - 264
• Main Authors: Smaliy, Radomyr V., Chaykovskaya, Aleksandra A., Shtil, Nataliya A., Yurchenko, Sergey A., Yurchenko, Aleksandr A., Lakhtadyr, Aleksandr I., Gorlova, Alina O., Kostyuk, Aleksandr N.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2015
• Subjects: Amines; Fluorine; Hydrogenation; Palladium; Pyrrole; Palladium; Amines; Fluorine; Hydrogenation; Pyrrole
• ISSN: 0022-1139; 1873-3328
• DOI: 10.1016/j.jfluchem.2015.09.017

Hydrogenation of trifluoroacylated pyrroles was investigated.
•An approach to CF3-bearing pyrrolidines was developed.•The CF3-bearing pyrroles were found to be easily hydrogenated by Pd/C promoted by HCl.•In some cases trifluoroacetyl groups were reduced into trifluoroethyl ones.•Wide scope of substrates was studied including stereochemistry.
Trifluoroacylated pyrroles and related compounds can be transformed to CF3-bearing pyrrolidines via a Pd/C-mediated hydrogenation under acidic conditions in high yields. The synthesis of several compounds of this type was considerably simplified as compared to formerly available procedures. Stereochemical aspects of the hydrogenation were studied and methods for both preparation and separation of diastereomerically pure products were developed.