Studies on organophosphorus compounds XXII The dimer of p‐methoxyphenylthionophosphine sulfide as thiation reagent. a new route to O‐substituted thioesters and dithioesters

Abstract

Simple alifatic and aromatic esters, such as ethyl, iso-propyl, and benzyl benzoates, benzyl butanoate, ethyl heptanoate, and ethyl 1 -and 2-naphthoate, respectively, react with the dimer of p-methoxyphenylthionophosphine sulfide 1 in anhydrous xylene at 140 "C to give the corresponding 0-substituted thioesters in nearly quantitative yields. Also simple alifatic and aromatic S-substituted thioesters, such as S-phenyl, S-benzyl and S-tert-butyl thiobenzoates, S-phenyl and S-benzyl thioacetates, and S-ethyl thiobutanoate, produced the corresponding dithioesters in nearly quantitative yields upon treatment with 1 in anhydrous toluene at 1 1 0 "C. 13C NMR data for the carbonyl-and corresponding thiocarbonyl carbons, have been recorded and a linear relation between the chemical shifts of C=S and C=O is found: 6(C=S) = 1.75.6(C=O) -79.6 for 0-substituted thioesters and 6(C=S) = 1.31.6(C=O) -22.1 for dithioesters. An anomalous reaction has been observed: Thiobenzoic acid, S,S'-methylene ester 2 reacted with 1 to give 4,5-diphenyl-1,3-dithiol-2-thion 3 .

Fluorocarbon and Hydrocarbon N‐Heterocyclic (C5–C7) Difluorooxymethylene‐Bridged Liquid Crystals

“…Trifluoromethanesulfonic acid alkyldiyl (1h-3h) and polyfluoroalkyldiyl esters 1f-3f were prepared by our group earlier by using the combination of trifluoromethanesulfonic acid and alkyl diol (1a-3a) or polyfluoroalkyl diol (1b-3b), respectively (Scheme 2). [14,16] In this article, the intermediates 3CCANO 2 and 5CCANO 2 , having the difluoromethyleneoxy moiety as a linkage group were synthesized by oxidative fluorodesulfuration as described by Kirch et al [17] These nitro compounds can be reduced by Zn and NH 4 Cl in CH 3 OH/THF solution to give 3CCANH 2 or 5CCANH 2 in ca. [12] Two methods have been developed for the introduction of a difluoromethyleneoxy moiety.…”

“…The diffraction patterns obtained for compounds 3CCA5F and 3CCA6H are shown in Figures 3 and 4, respectively. At 160°C (Figure 3, b), a sharp scattering at 5.30°is observed corresponding to a d spacing of 16.65 Å given in the small angle region; a diffuse scattering at 17.52°, corresponding to a d spacing of 5.06 Å, was also obtained. At 180°C (Figure 3, a), the plot shows only a wide diffraction peak in the wide angle region and no diffraction peak was found in the small angle region; combined with POM, these results indicate an isotropic phase at this temperature.…”

A Focused Review of Synthetic Applications of Lawesson’s Reagent in Organic Synthesis

“…Lawesson's reagents were first systematically studied by Lawesson and co-workers in 1978, mainly for carbonyl groups' transition to thiocarbonyls [7][8][9]. LR is commercially available and widely used in organic synthesis.…”

Lewis base-free thiophosphonium ion: a cationic sulfur atom transfer reagent

“…3,4 Trigonal planar dithiophosphoranes have a natural tendency to dimerise or trimerise forming dithiadiphosphetanes or trithiatriphosphinanes, in which phosphorus adopts a tetrahedral binding mode. Since the discovery of the potential of dithiophosphoranes as thionating reagents, 5 scientists were eager to isolate the monomeric and thus more reactive species. In 1983, the groups of Appel, 6 as well as Majoral and Navech, 7 synthesised the first monomeric dithiophosphorane II (Scheme 1) by using a very bulky 2,4,6-tri-tert-butylphenyl group, which prevents dimerisation upon blocking both sides of the PS 2 plane but decomposes at 110 1C via isomerisation.…”

“…Only one of the two crystallographically independent molecules of 3 and only one part of the disordered isopropyl group and N 2 PSCl moiety is depicted. Selected bond lengths [Å] and angles[1] of[4][BArF 24 ]: P-N1 1.5578(12), P-N4 1.5606(12), P-S 1.8967(5), N1-P-N4 108.02(6), N1-P-S 124.79(5), N4-P-S 127.17(5).…”