A Mild and Efficient Method for Selective Acetylation of Amines

Primary and secondary amines were acetylated under mild conditions by means of 3-acetyl-1,3-thiazolidine-2-thione [ATT(1)]. The reaction was successfully applied to selective acetylation of a primary amino group of diamines containing a primary and a secondary amino groups or exclusive N-acetylation of amino alcohols.     

Synthesis of thiiranylmethylamides from N(S)-allylthiooxamides

Abstract

The first representative of N¹-substituted N²-thiiranylmethylethaneamides has been synthesized from N¹-substituted N²-allylethaneamides. The formation of thiiranylmethylamides passes through bromine-induced cyclization of N-allylthioamide moiety followed by hydrolysis of 5-bromomethyl-1,3-thiazoline ring.     

Selenium Catalyzed Synthesis of Cyclic Thionecarbamates from Hydroxyisocyanides and Sulfur

Abstracts

1,3-Oxazine-2-thiones were prepared from 3-hydroxyisocyanides and sulfur in the presence of catalytic amounts of selenium.     

Tetrakis(thione)platinum(II) complexes: synthesis,spectroscopic characterization,crystal structures,and in vitro cytotoxicity

A new series of platinum(II) complexes based on thione ligands with general formula [Pt(thione)₄]X₂ (X^??=?Cl^?, NO₃^?) has been synthesized and characterized using CHNS elemental analysis, infrared, ¹H and ¹³C solution-state NMR as well as ¹³C and ¹⁵N solid-state NMR spectroscopy, and X-ray crystallography. The spectroscopic methods confirm the coordination of Pt(II) with thiocarbonyl groups via sulfur of the thione ligands. The X-ray structures showed a distorted square planar geometry for 1, [Pt(MeImt)₄]Cl₂ (MeImt = N-Methylimidazolidine-2-thione) while the hydrogen bonding interactions in 7, [Pt(iPrImt)₄](NO₃)₂·0.6(H₂O) induce a bent see-saw distortion relative to the ideal square planar geometry. The in vitro cytotoxicity studies showed that 2, [Pt(EtImt)₄]Cl₂ is generally the most effective, a two-fold better cytotoxic agent than cisplatin and carboplatin against MCF7 (human breast cancer).     

Synthesis and photochromic properties of 1,2-dihetarylethenes with 1,3-dioxole- and 1,3-oxazole-2-thione bridges

Methods for the synthesis of substituted bis(2,5-dimethyl-3-thienyl)ethenes with 1,3-dioxole- and 1,3-oxazole-2-thione fragments as ethene bridges were developed. These compounds exhibit photochromic properties. Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1299–1301, May, 2005.     

Hydrogen-bond networks of 1,3-imidazolidine-2-thione: synthesis and structures of complexes of silver(I), copper(I), cadmium(II) and zinc(II)

Solution reactions of silver(I), copper(I), cadmium(II) and zinc(II) salts with 1,3-imidazolidine-2-thione (imdt) under diverse conditions yielded four complexes: [Cd(SC₃H₆N₂)₂(Ac)₂] (1), [Zn(SC₃H₆N₂)₂(Ac)₂] (2), [Cu₂(SC₃H₆N₂)₆]SO₄ (3) and [Ag₂(SC₃H₆N₂)₆]SO₄ (4). Complexes 1 and 2 are 1D and 2D hydrogen-bond aggregations. Complexes 3 and 4 are isostructural 3D hydrogen-bond networks. The diverse coordination modes of imdt and different anions are the major factors for three distinct hydrogen-bond structures.     

Synthesis of 2-D graphite-like and 3-D diamond-like silver(I) polymers with 1,3-imidazolidine-2-thione

Two metal–organic coordination polymers, [Ag₂(imdt)₃(OAc)₂] _n (1) (imdt = 1,3-imidazolidine-2-thione, OAc = CH₃COO^?) and [Ag(imdt)Cl] _n (2), were synthesized under similar conditions by using Et₃N (triethylamine) as buffering agent. X-ray diffraction shows that 1 crystallizes in the monoclinic system, C2 /c space group, a = 13.822(5) Å, b = 9.082(3) Å, c = 16.965(6) Å, V = 2114.2(14) ų, Z = 8, D _c = 2.012 g cm^?3. Compound 2 crystallizes in the orthorhombic system, P2₁2₁2₁ space group, a = 7.993(6) Å, b = 7.993(6) Å, c = 10.548(7) Å, V = 673.9(7) ų, Z = 4, D _c = 2.419 g cm^?3. Both 1 and 2 exhibit different architectures due to their different anions. Compound 1 shows a 2-D graphite-like network structure and 2 shows a 3-D diamond-like network structure.     

N—烃氧丙酰基四氢噻唑—2—硫酮的合成

在三聚氯氰存在下由烃氧丙酸与四氢噻唑-2-硫酮反应得到N-烃氧丙酰四氢噻哇-2-硫酮(2a-i),由2a,c-h与格氏试剂反应得到烃氧乙基苯基酮(3a,c-h).产物2a-i未见报道.     

Synthesis of 1-Bromo-3-butyn-2-one and 1,3-Dibromo-3-buten-2-one

Synthetic procedures for the preparation of 1-bromo-3-butyn-2-one and 1,3-dibromo-3-buten-2-one are given. These compounds are prepared from 2-bromomethyl-2-vinyl-1,3-dioxolane, which can readily be prepared from 2-ethyl- 2-methyl-1,3-dioxolane. The synthetic routes are as follows: 2-bromomethyl-2-vinyl-1,3-dioxolane is converted to 2-(1,2-dibromoethyl)-2-bromomethyl-1,3-dioxolane. Double dehydrobromination with ^tBuOK affords 2-ethynyl-2-bromomethyl-1,3-dioxolane. Formolysis with formic acid gives 1-bromo-3-butyn-2-one. Deacetalized 2-bromoethyl-2-vinyl-1,3-dioxolane was treated with Br₂ and Li₂CO₃/12-crown-4 in tetrahydrofuran to give 1,3-dibrom-3-buten-2-one in moderate yield.     

Zum Mechanismus der Reduktion von 1,3-Benzodithiol-2-thionen

Carbophilic reaction of 1,3-benzodithiole-2-thione (1) with trideuteroborane · dimethylsulfide, synthesized from NaBD₄ and BF₃ ·Me ₂S inTHF, gave 2,2-dideutero-1,3-benzodithiole (5 b) as well as the minor side-products7 b,8 and9 b.

     

Convenient approach to chiral 4-monosubstituted 1,3-oxazolidine-2-thiones

Chiral 4-monosubstituted 1,3-oxazolidine-2-thiones are regarded as one of the modified version of Evans auxiliaries in asymmetric aldol condensation, which can generate two adjacent chiral carbon centers in one time They have advantages over Evans auxiliaries in some aspects, however, their application is highly limited by their preparation approaches as toxic or flammable chemicals are involved. Here, a mild and applicable procedure for preparing the chiral oxazolidine-2-thione auxiliaries has been developed in this article. Potassium ethylxanthate and the corresponding chiral amino alcohols as the starting material in absolute ethanol are mixed and the mixture are heated under reflux for 1?h in open air to provide 1,3-oxazolidine-2-thiones chiral auxiliaries in moderate to excellent yields.     

Heterocyclic thioamides of copper(I): Synthesis and crystal structures of copper complexes with 1,3-imidazoline-2-thiones in the presence of triphenyl phosphine

Reaction of copper(I) chloride with 1,3-imidazoline-2-thione (imzSH) in the presence of Ph₃P in 1:2:2 or 1:1:2 (M:L:PPh₃) molar ratios yielded a compound of unusual composition, [Cu₂(imzSH)(PPh₃)₄Cl₂] · CH₃OH (1), whose X-ray crystallography has shown that its crystals consist of four coordinated [CuCl(1κS-imzSH)(PPh₃)₂] (1a), and three coordinated [Cu(PPh₃)₂Cl] (1b) independent molecules in the same unit cell. In contrast, crystals of complexes of copper(I) bromide/iodide are formed by single molecules of [CuBr(1κS-imzSH)(PPh₃)₂] · H₂O (2) and [CuI(1κS-imzSH)(PPh₃)₂] (3), respectively, similar to molecule 1a. The related ligand, 1,3-benzimidazoline-2-thione (bzimSH) formed a complex [CuBr(1κS-bzimSH)(PPh₃)₂] · CH₃COCH₃ (4), similar to 2. The formation of 1a and 1b has been also revealed by NMR spectroscopy. The NMR spectra of 2–4 also showed weak signals indicating formation of compounds similar to 1b. It reveals that the lability of the Cu–S bond varies in the order: Cl ? Br ∼ I. Weak interactions {e.g. C–H?π electrons of ring, –NH?halogens/oxygen, C–H?halogens/oxygen, π?π (between rings)} have played an important role in building 2D chains of complexes 1–4.     

Synthesis of substituted 2-amino-1,3-thiazine-6-thiones

The reaction of thiourea with l-acyl-2-bromoacetylenes in AcOH in the presence of BF₃·Et₂O affords 2-amino-4-phenyl(2-thienyl)-1,3-thiazine-6-thiones in high yields. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 11, pp. 1947–1949, November, 2000.     

Improved Synthesis of 1-Bromo-3-buten-2-one

A convenient procedure for the synthesis of 1-bromo-3-buten-2-one, 4, from commercially available 2-ethyl-2-methyl-1,3-dioxolane, 1, is described. The procedure involves three reaction steps: (1) The acetal 1 is converted to 2-(1-bromoethyl)-2-bromomethyl-1,3-dioxolane, 2, by reacting 1 with elemental bromine in dichloromethane to yield 98% of 2. (2) Dehydrobromination of 2 with potassium tert-butoxide in tetrahydrofuran gives 2-bromomethyl-2-vinyl-1,3-dioxolane, 3, in 84–93% yield. (3) Removal of the acetal protection from 3 by formolysis for 6–10 h afforded 1-bromo-3-buten-2-one, 4, in 85–94% yield. A more rapid method is acid hydrolysis of 3 under microwave activation (100 °C, 8–10 min), by which 4 was obtained in 75% yield. Full experimental details are given.

HSCN condensation with ulosides: preferred formation of carbohydrate-fused hemiaminals of the 4-hydroxy-1,3-oxazolidine-2-thione type

Selected ulofuranosides and ulopyranosides react with thiocyanic acid to give good yields of stable carbohydrate-fused hemiaminal 1,3-oxazolidine-2-thiones.     

Small libraries of fused quinazolinone-sugars. Access to quinazolinedione nucleosides

Unprotected carbohydrates can readily be converted into base-modified nucleosides and deoxynucleosides through a short sequence involving the condensation of anthranilic acid derivatives with a suitably protected sugar-derived 2-alkylthio-1,3-oxazoline.     

配合物{[Cu(hmtade)][Ni(dmit)2]}2·4DMSO的合成、表征及晶体结构

合成了配合物{[Cu(hmtade)][Ni(dmit)2]}2·4DMSO(1)(hmtade为5,7,7,12,14,14-六甲基-1,4,8,11-四氮杂环十四-4,11-二烯; dmit为1,3-二硫杂环戊二烯-2-硫酮-4,5-二硫醇; DMSO为二甲亚砜), 采用元素分析、红外光谱和紫外-可见光谱进行了表征, 并用X射线衍射法测定了晶体结构. 该晶体属于单斜晶系, P21/n空间群; 晶胞参数: a=1.49952(6) nm, b=1.77229(7) nm, c=3.1275(1) nm, β=102.442(1)°, V=8.1163(5) nm3, Dc=1.558 Mg/m3, Z=8, F(000)=3944, μ(Mo Kα)=1.637 mm-1, S=1.016, (Δ/σ)max=0.001, R1=0.0673, wR2 =0.1672[I>2σ(I)]. 晶体结构研究表明, 配合物{[Cu(hmtade)]·[Ni(dmit)2]}2·4DMSO包含2个[Cu(hmtade)][Ni(dmit)2]子单元. 每个子单元中, 1个dmit中的1个S原子与Cu及Ni配位, 形成异双核Cu—Ni配合物. 其中Cu(Ⅱ)为五配位的四方锥构形, Cu—N键长在0.1949(5)~0.2007(4) nm范围内, Cu—S键长分别为0.28913(18)和0.28952(18) nm; 配阴离子[Ni(dmit)2]2-为畸变四方形, Ni—S键长在0.21729(16)~0.21905(17) nm范围内. 溶剂分子DMSO与配体hmtade形成了N—H…O氢键. 通过分子内S…S和S…H短接触形成了二聚体, 二聚体之间通过S…S短接触形成一维链状结构, 并通过S…S, S…H和C…H短接触进一步形成二维和三维结构.     

New Sulfur,Silicon and Phosphorus Containing Reagents

The problems of synthesis and transformations of new organoelement reagents containing sulfur, silicon and phosphorus (S-P-O-Si, P(S)-S-Si) are discussed.