Abstract: Simple and efficient approaches to the synthesis of fluorinated benzoazaheterocycles with good yields are reported. Firstly a series of polyfluorinated 2-alkynylanilines - the versatile building blocks - was synthesized by the Sonogashira reaction of o-iodoaniline with terminal alkynes. Then the transformations of the obtained 2,3,4-trifluo-6-alkynilanilines in the presence of KOH or PdCl2 in MeCN, and in the presence of monohydrate of p-toluenesulfonic acid (p-TSA center dot H2O) in MeOH, EtOH or benzene were investigated. It was found that Ph- and n-Bu-containing alkynylanilines by action of PdCl2 in MeCN underwent an intramolecular cyclization reaction to produce the corresponding indoles in high yields. The reaction of KOH with alkynes containing the tertiary alcohol function at the triple bond produced the unsubstituted on the pyrrole ring indole. It was found that fluorinated 2-alkynilanilines can be transformated into indoles, 2-arylketones and 2,3-dihydroquinolines by action of p-TSA center dot H2O in boiling alcohols, depending on the substituent at the triple bond. The use of benzene as a solvent in the reaction of p-TSA center dot H2O with polyfluorinated alkynes, bearing an alcohol group resulted in representative series of 2,3-dihydroquinolinones containing a substituents R-1 and R-2 in the 2nd position of their structure (R = H, H; Me, Me; H, i-Pr; H, Ph).

Cite: Politanskaya L. , Petyuk M. , Tretyakov E.
Transformation of fluorinated 2-alkynylanilines by various catalytic systems
Journal of Fluorine Chemistry. 2019. V.228. UNSP 109394 . DOI: 10.1016/j.jfluchem.2019.109394 WOS Scopus РИНЦ

Dates:

Published print:

Dec 1, 2019

Identifiers:

Web of science	WOS:000501399400002
Scopus	2-s2.0-85074458188
Elibrary	41693150
OpenAlex	W2981049166

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