Alkynyl Fischer carbene complex as a traceless directing group for the regioselective cycloaddition of dithiolethiones to arylacetylene: synthesis of E-dithiafulvene thione and dithioesters

Abstract

A phenylethynyl Fischer carbene complex was used as a traceless directing group for the regioselective cycloaddition of dithiolethiones to arylacetylene, which constitutes the first synthesis of E-dithiafulvene thione or dithioesters.

DFT Study of Thermal 1,3-Dipolar Cycloaddition Reactions between Alkynyl Metal(0) Fischer Carbene Complexes and 3H-1,2-Dithiole-3-thione Derivatives

“…In this regard, we have recently reported the first synthesis of pure regioisomer E -dithiafulvene thione via the 1,3-dipolar cycloaddition reaction between a series of 5-substituted-3 H -1,2-dithiole-3-thione derivatives with alkynyl Fischer carbene complexes followed by a demetalation−decarboxylation step by treatment with neutral aluminum oxide (Scheme ) . This transformation is important since it allows the easy access to reaction products that present interesting properties in the organic materials field and because the cycloadditions that involve organic propiolates usually lead to mixtures of cycloadducts. ,,,, A highly asynchronous cycloaddition reaction due to the thiono group of 3 H -1,2-dithiole-3-thione was initially proposed for the first step of the transformation involving Fischer carbene complexes . However, the reasons for the observed complete regioselectivity and the low temperatures required for the process to occur remain not fully understood.…”

Remarkable effect of the dithiafulvene structures on their capacity as reducing agents: Influence of conjugated thiocarbonyl group

“…The synthesis of the dithiafulvene units, DTF 2, showed in Scheme 1, has been reported previously by our group, 12 as a regioselective cycloaddition of 1,2-dithiole-3-thiones rings to an alkynyl Fischer carbene complex. Specifically, in the present work we extend the use of DTF as reducing agent for the preparation of oxidized DTF-AgNPs and PdNPs, employing DTFBut as a proof of concept example.…”

“…DTF were synthesized by the regioselective cycloaddition of dithiolethiones and alkynyl Fischer carbene Complexes, which has been previously reported in detail. 12 Synthesis of capped metal colloids. In a typical preparation of oxidized DTF-MNP, a solution of DTF in AcN (6.1 µM) was mixed together with the metal precursor salt solution to reach different M/DTF ratios.…”

“…10 Likewise, Adows and Zhao have also reported the ability of 5-((4,5-bis(decylthio)-1,3-dithiol-2-ylidene)methyl)isophthalic acid, carboxylated DTF 1 and TTF derivative (Scheme 1) as reducing agents of Au (III). 11 In the present work, we study different DTF 2 derivative compounds (scheme 1), synthetized in our group, 12 as reducing agents not only of Au (III) but also of other metals cations such as Ag(I) and Pd (II), giving as product metal NPs (MNPs) capped with oxidized DFT. The oxidized DTFBut, was produced and characterized by spectroelectrochemistry (SE) in the absence of the metal precursors and the spectral data of this species fits very well with those observed in the chemical redox reaction 3 reported.…”

Synthesis and Reactivity of 3H-1,2-dithiole-3-thiones

“…A notable and rare example of regioselective addition of Fischer's phenylethyl carbene complex 68 to 1,2-dithiole-3-thiones was reported by Rossi and Torroba [89]. The carbene moiety of Fischer's alkyne acted as an electron-withdrawing group increasing the electrophilic character of alkyne 68 (Scheme 44).…”