Aus silylgeschütztem 4′‐Hydroxyacetophenon (1) entsteht durch Umsetzung mit Schwefelkohlenstoff und Iodmethan in Gegenwart von Kalium‐tert‐butylat der silylsubstituierte 4′‐Hydroxy‐β‐hydroxydithiozimtsäuremethylester (2). Die Molekülstruktur des nach Abspaltung der Schutzgruppe entstehenden Esters 3 wurde durch Röntgenstrukturanalyse bestimmt. Die phenolische OH‐Gruppe wird mit DL‐α‐Liponsäure (4) verestert. Der so zugängliche 4′‐(1, 2‐Dithiolan‐3‐pentanoyl)‐β‐hydroxydithiozimtsäuremethylester (5) bildet mit NiII, PdII und PtII Komplexe.

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Synthesis and Analytical Characterization of Functionalized β‐Hydroxydithiocinnamic Acids and their Esters. Complex Chemistry towards Nickel(II), Palladium(II), and Platin(II)Starting from silyl‐protected 4‐hydroxy acetophenone (1) the 1,1‐ethenedihiolato complexes 3–5 were synthesised using carbon disulfide and potassium‐tert‐butylate as a base. After being deprotected, the resulting 4‐hydroxy‐substituted complexes 6–8 were esterified with DL‐α‐lipoic acid to obtain the compounds 9–11. The resulting complexes were characterized using NMR spectroscopy, mass spectrometry and IR spectroscopy.3‐substituted β‐hydroxydithiocinnamic acid methyl ester (12) was obtained via an analogous path of reaction using silyl‐protected 3‐hydroxy acetophenone (2), carbon disulfide and methyl iodide. After removing of the silyl group the resulting hydroxy group was esterified with DL‐α‐lipoic acid. Using the dithioacid ester 14 as a ligand the NiII (15), PdII (16) and PtII (17) [O,S] complexes were obtained.

Starting from 4-bromoacetophenone 1, the 4-bromo-β -hydroxydithiocinnamic acid 2 and the 4-bromo-β -hydroxydithiocinnamic acid hexyl ester 3 were prepared using carbon disulfide and potassium-tert-butylate as a base. Acting as a ligand, the acid gives 1,1-ethenedithiolato complexes with (Ph3P)2Pt(II) (4a), (Et3P)2Pt(II) (4b), dppePt(II) (4c), (Ph3P)2Pd(II) (4d), dppePd(II) (4e), and dppeNi(II) (4f). In contrast to the acid, the deprotonated ester 3 forms a monoanionic bidentate ligand. [O,S] Complexes of Pt(II) (5a), Pd(II) (5b) and Ni(II) (5c) were obtained. All complexes have been fully characterised using 1H NMR, 13C NMR and 31P NMR spectroscopy, mass spectrometry, infrared spectroscopy and elemental analyses. The molecular structures of the complexes 4b and 5a - 5c were determined by X-ray diffraction analyses.

Some 1,1 -ethenedithiolato complexes of nickel(II), palladium(II), and platinum(II) with dif