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Trifluoromethylated 3‐(Pyrazol‐1‐yl)propanamide (PPA) Ligands
Author(s) -
Liebing Phil,
Edelmann Frank T.
Publication year - 2020
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.202000148
Subject(s) - chemistry , trifluoromethyl , elemental analysis , pyrazole , solid state , nuclear magnetic resonance spectroscopy , medicinal chemistry , stereochemistry , proton nmr , hydrogen bond , crystallography , organic chemistry , molecule , alkyl
The new PPA ligands 3‐[5‐methyl‐3‐(trifluoromethyl)‐1 H ‐pyrazol‐1‐yl]propanamide (CF 3 MePPA; 3 ) and 3‐[3,5‐bis(trifluoromethyl)‐1 H ‐pyrazol‐1‐yl]propanamide ((CF 3 ) 2 PPA; 4 ) were synthesized by Aza‐ Michael addition of the specific pyrazole derivatives to acrylamide. Both products were characterized by elemental analyses, IR and NMR spectroscopy, and mass spectrometry. X‐Ray structure determination of 3 revealed the presence of a one‐dimensional hydrogen‐bonded structure in the solid state. The ligating ability of the new ligands towards PdCl 2 was studied, showing that 3 behaves similar to Me 2 PPA and reacts cleanly with PdCl 2 to afford the sparingly soluble complex PdCl 2 (CF 3 MePPA‐ κN ) 2 . By contrast, the donor ability of pyrazolyl group in 4 was found to be considerably reduced, thus resulting in the formation of the unusual complex PdCl 2 {(CF 3 ) 2 PPA‐ κN }{(CF 3 ) 2 PPA‐ κO }.