The Cycloaddition Reaction of Lawesson's Reagent with 1,3-Dienes

Lawesson's reagent undergoes [2 + 4] cycloaddition reaction with 2-methyl-1, 3-butadiene,cyclopentadiene to yield heterocycles 4 and 5, respectively.

The Cyclization Reactions of Lawesson's Reagent with Bifunctional Substrates

The cyclizaion reactions of Lawesson's reagent(LR) with the substrates containing two functional groups such as hydroxy groups,amino groups, has been applied to prepare the O-P-O,N-P-N type 5-membered and 6-membered phosphorus heterocycles.The heterocyclizaional possibility of LR with bifunctional compounds was also discussed.

Thionization Method of Glycosyl Urea and Carbamide Sugars

This work is describing a thionization method for glycosyl urea and carbamide of sugars by using the Lawesson’s reagent. It is proposed the method based on the interaction of glycosyl urea and carbamide of sugars with the Lawessons reagent at a 1:1 ratio in the presence of a pyridine. As a result, sulfur-containing derivatives of sugar carbamides are obtained with the help of Lawesson’s reagent. Obtained experimental data are indicating the developed new method for thionization of sugar carbamides, which opens up broad possibilities for synthesis of various carbohydrate derivatives of thiourea. Significance of this work is that, thiourea derivatives are promising bactericidal, fungicidal and anti-inflammatory drugs. Therefore, the preparation of thiourea derivatives and the study of their properties remain topical tasks in the field of chemistry.

Facile Synthesis of Five-membered Phosphoroheterocycles Bearing N-P-N and S-P-N Moieties

New reactions of Lawesson reagent (LR) with alpha -hydroxy (amino)nitriles have been studied. The experimental results showed that the five-membered phosphoroheterocycles 2 and 4 bearing N-P-N or S-P-N moiety could be readily prepared in high yields. Meanwhile, the possible mechanism of the reactions was also discussed.

Crystal Structures and Antimicrobial Activity of Two Phosphorus Compounds

One phosphorus heterocycle compound 1, C13H13N2OPS, was synthesized by the reaction of Lawesson＇s reagent （LR） with o-phenylene diamine. The crystal belongs to the orthorhombic system, space group P212121 with a = 5.5274（11）, b = 8.1603（16）, c = 28.830（6） A, V = 1300.4（4） A^3, Z = 4, Mr= 276.28, Dc = 1.411 g/cm^3, F（000） = 576,μ = 0.360 mm^-1, R = 0.0259 and wR = 0.0652 for 1414 observed reflections with I 〉 2σ（I）. While compound 2, C14H17N2O2PS, was obtained as a ring-cleavage product of compound 1. This crystal is of monoclinic system, space group P21/c with a = 9.5619（19）, b = 21.879（4）, c = 7.3618（15） A, β= 103.03（3）°, V=1500.4（5） A^3, Z = 4, Mr= 308.33, Dc = 1.365 g/cm^3, F（000） = 648,μ = 0.325 mm^-1, R = 0.0383 and wR =0.0742 for 2283 observed reflections with I 〉 2σ（I）. Phosphorus atom in each compound bonds with sulfur and carbon atoms using sp^3 hybrid orbitals, and crystals of these two compounds are formed and stabilized by intermolecular hydrogen bonds and Van der Waals＇ forces. The special structure of compound 1 leads to its good antimicrobial activity against staphylococcus aureus.

Crystal Structure of 1,3-Dibenzyl-2-benzylaminothiocarbonyl-1,3,4- diazaphospholidin-5-thione-4-sulfide

The title compound, C31H30N3OPS3, crystallizes in monoclinic system, space group P21/n,with a = 11.839(7), b = 8.975(5), c = 29.15(2)? b = 100.07(1), V = 3049(3)?, Z = 4, Dc = 1.280g/cm3, Mr = 587.73, F(000) = 1232, m = 0.324mm-1, the final R = 0.0434 and wR = 0.1140 for 4787 observed reflections with I >2s(I). The title compound is a five-membered heterocycle containing a phosphorus, two nitrogen and two carbon atoms.The analysis result shows that the five-membered ring is nearly coplanar. The P(1)N(1) bond length(1.685? indicates the existence of pd?bond between N(1) and P(1) atoms of the title compound.

Thioxanthene-9-thione Mediated MMA Polymerization

In the ＂cycloketyl radical mediated living polymerization＂ （CMP） process, a cycloketyl compound, [9,9＇]bixanthenyl-9,9＇ diol （BIXAN） was ultilized as initiator and mediator. The cycloketyl （CK） radical was used as the dormant radical to achieve the increase of molecular weight. Herein, a series of cycloketyl thioketones were synthesised by Lawesson＇s reagent by one step reaction with high yeild, and we found that, when a special cyeloketyl thioketone compound, thioxanthene-9-thione （TXT）, was added to a routine radical polymerization system, TXT could capture chain radical, and simultaneously formed an radical analogous to CK radical in structure, which could trigger the growth of polymer chains. This simple system was efficient to initiate the polymerization of methyl methacrylate （MMA） and in all cases the molecular weights increased with the increase of conversions. By the end-group analysis with 1H-NMR and MALDI-TOF MS, it was confirmed that the P-STXT radical was used to control the polymerization. The re-initiating reactions were achieved when PMMA was used as the macro-initiator.