Emilia Obijalska

Synthesis of β-amino-α-trifluoromethyl alcohols and their applications in organic synthesis

Abstract A comprehensive overview on methods applied for syntheses of β-amino-α-trifluoromethyl alcohols, including stereocontrolled variants, is presented. In addition, reported cases of the exploration of β-amino-α-trifluoromethyl alcohols for the preparation of trifluoromethylated peptidomimetics and other biologically active, fluorinated compounds are discussed. Attractive opportunities for their applications as organocatalysts are also presented.

Recent progress in the synthesis of 1,2,4-benzotriazines (microreview)

Although first synthesis of 1,2,4-benzotriazine was performed at the end of 19th century still new methods for their preparation are developed. This microreview combines recent (2006–2017) information on the strategies used for the synthesis of 1,2,4-benzotriazines – [4+2] cycloaddition reactions, diverse cyclocondensations, heterocyclization of N-(2-aminoaryl)hydrazides, etc.

Efficient synthesis of tri- and difluoroacetyl hydrazides as useful building blocks for non-symmetrically substituted, fluoroalkylated 1,3,4-oxadiazoles

A convenient and efficient approach to 2-arylamino-5-fluoroalkyl-1,3,4-oxadiazoles has been established via heterocyclization of tri- and difluoroacetylated thiosemicarbazides using dicyclohexylcarbodiimide. A heterocyclization performed with selected thiosemicarbazides under basic conditions led to 4-aryl-5-fluoroalkyl-2,4-dihydro-3H-1,2,4-triazole-3-thiones in moderate yields. The starting fluoroacetylated thiosemicarbazides were prepared by fluoroacetylation of benzyloxycarbonyl-protected hydrazine with a corresponding anhydride, followed by hydrogenolytic deprotection and reaction with arylisothiocyanates. Fluoroacetylated semicarbazides were prepared similarly, but all attempts to achieve their heterocyclization were unsuccessful.