硫醚

In chapter three, the activating agents of ytterbium have been examined. Barbier-type reaction promoted by ytterbium metal was examined. The experimental results shown that the yield of Barbier reaction of imines with allylic bromide promoted by ytterbium is higher than that of aldehydes and ketones with allylic bromide under the same reaction conditions. In this chapter, the reductive cleavage of Se-Se and S-S bond induced by ytterbium metal was also studied.

首先研究了金属镱的活化剂以及活化方法，接着考察了金属镱促进的Barbier反应及其在合成高烯丙基胺和高烯丙基醇中的应用，以及影响该反应的主要因素；究了金属镱促进的二硫醚和二硒醚的S—S键和Se—Se键的还原断裂，继而与氯代烃，胺基甲酰氯反应生成相应的硫醚，硒醚，胺基甲酸硫代酯和硒代酯。

The present invention relates to the depolymering cyclization reaction of aromatic dithio ether polymer to prepare aromatic cyclic dithio ether compound under the presence of mercapto group containing compound and alkali matter.

本发明涉及利用芳香双硫醚聚合物的解聚成环反应来制备芳香双硫醚环状化合物的方法。该方法采用芳香双硫醚聚合物在含巯基的化合物和碱性物质存在的条件下发生解聚成环反应生成双硫醚环状化合物。

SMM is the main precursor substance of DMS, and Cystine is one of the precursor substances of DMS in vegetables.

硫甲基蛋氨酸是蔬菜中甲硫醚主要的前体物质，胱氨酸是蔬菜中甲硫醚的前体物质之一。

Eleven novel 2-alkylthio-5-(5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-5-yl)-1,3,4-oxadiazole derivatives (5) and six novel 2-alkylthio-5-(5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-5-yl)-1,3,4-thia- diazole derivatives (8) have been designed and synthesized by using 5-amino-3-ethoxycarbonyl-1H-1,2,4-triazole as a starting material.

以5-氨基－1H-1，2，4-三唑－3-羧酸乙酯为起始原料，设计合成了11个新型的2-取代硫醚－5-（5，7-二甲基－1，2，4-三唑并[1，5-a]嘧啶基）-1，3，4-恶二唑类化合物(5)和6个新型的2-取代硫醚－5-（5，7-二甲基－1，2，4-三唑并[1，5-a]嘧啶基）-1，3，4-噻二唑类化合物(8)。

1A series ofω-alkylmercapo acid were synthesized by two methods:one involved the reaction of the appropriateω-bromoalkyl acid with mercaptide under the presence of base;the other method was used only for the long alkyl compound by the reaction ofω-alkenyl acid and alkanethiol in the presence of AIBN.

正是基于以上考虑，本论文探索了合成下沿带有硫醚官能团，而上沿带有偶氮官能团的杯[4]芳烃衍生物的方法，进行了以下研究： 1采用ω-溴代羧酸和烃基硫醇在碱性条件下发生反应，或由ω-烯基羧酸和硫醇在AIBN的存在下反应，得到了ω-硫醚羧酸，使用氯化亚砜将羧酸转化为酰氯。

A series of sulfonated poly(arylene thioether/ether phosphine oxide)s was prepared by direct polycondensation of sBFPPO and BFPPO with the diphenol-type or dimercapto-type monomers such as hydroquinone, bisphenol-A, 4,4'-biphenol, 4,4'-diphenol (6F), 1,5-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, and 4,4'-thiobisbenzenethiol, respectively.

将BFPPO与sBFPPO分别与多种二羟基或二巯基单体，如对苯二酚、双酚A、4，4'-二苯酚、双酚F、1，5'-二羟基萘、4， 4'-二羟基二苯硫醚和4，4'-二巯基二苯硫醚，直接共聚制备了一系列磺化聚芳醚三苯基氧膦，侧重考察了二羟基和二巯基单体结构单元对产物的耐氧化性能的影响。

In chapter four, the preperation of ytterbium diiodide was examined. The reductive cleavage of Se-Se bond and S-S bond induced by ytterbium diiodide was investigated. The reaction of diselenides and disulfides with allylic bromide promoted by ytterbium diiodide was also examined. The intermolecular Barbier-type reaction induced by ytterbium diiodide was studied. In the last section of this chapter, the intermolecular reductive coupling of nitriles with azides induced by samarium diiodide was investigated.

第四章，研究了二碘化镱的制备方法，以及二碘化镱作为一种优良的单电子转移试剂在有机合成中的应用：二硒醚的Se--Se键和二硫醚S-S键的还原断裂，及其在合成烯丙基硒醚，硒代酯和烯丙基硫醚，硫代酯中的应用，实验结果表明二碘化镱也能促进分子间的Barbier反应，而文献认为二碘化镱不能促进分子间的Barbier反应；最后研究了二碘化钐促进的叠氮化合物与腈的交叉还原偶联反应，一步高收率地制备脒的方法。

The chapter two was focused on the samarium diiodide promoted organic reactions and their applications in organic synthesis, firstly, a new synthesis of highly substituted cyclopentadienes from a,β-alkynone promoted by samarium diiodide was investigated and the highly substituted cyclopentadienes were prepared in moderate to good yields under mild conditions. Secondly, the Michael addition and Michael-aldol tandem reaction of diorganyl diselenides or diorganyl disulfides with α,β-alkynones mediated by samarium diiodide were studied and a series of alkenylsulfides and alkenylselenides were prepared in good yields. Then the highly regioselecfive nucleophilic addition of the allylsamarium bromide to α,β-alkynones were explored. We found that the allylsamarium bromide reacts with α,β-alkynones to afford regiospecificly 1. 2-nucleophilic addition products in good yields under mild condition. At last we studied the coupling reaction of aryl halides promoted by NiCl〓/PPh〓/Sm〓.

第二章 研究了二碘化钐、金属钐促进的有机反应：1、二碘化钐促进下α，β-炔基酮的偶联环化反应，提供了一种制备多取代环戊二烯的新方法；2、二碘化钐促进下的二硫醚、二硒醚与α，β-炔基酮的Michael加成反应，为高产率地制备多取代的烯基硫或烯基硒化合物提供了方便可靠的新方法；3、二碘化钐促进下的二硫醚、二硒醚与α，β-炔基酮和醛、酮的Michael—aldol串联反应，提供了一种一锅法高产率地制备多取代的含硫的烯丙基醇或含硒的烯丙基醇类化合物的方便可靠的原子经济性的新方法；4、烯丙基溴化钐与α，β-炔基酮的高度区域选择性的1，2-亲核加成反应；5、NiCl〓/PPh〓/Sm〓促进的卤代芳烃的偶联反应-一种从各种卤代芳烃制备联苯类化合物的有效方法。

The catalytic transformation pathway can change to decrease the yield of hydrogen and yield methyl-contained sulfides such as methyl mercaptan, dimethyl sulfide and dimethyl disulfide, but overlarge concentration of methanol would holdback the transformation of isobutyl mercaptan. The transformation of isobutyl mercaptan was favorable if the volume ratio of methanol and benzene was 0.2.The addition of methanol assume certain effect on the catalytic cracking of di-n-butyl sulfide in solvent benzene but without changing the cracking reaction mechanism of di-n-butyl sulfide.

甲醇也可以使异丁硫醇的催化转化路径发生改变降低硫化氢的产率，生成甲硫醇、甲硫醚及二甲基二硫化物等含甲基硫化物，但甲醇的浓度过高会抑制异丁硫醇的转化，在反应体系中当甲醇的体积占到溶剂苯体积的20%时对异丁硫醇的转化较为有利；甲醇的添加对丁硫醚在溶剂苯中的催化裂化有一定影响，但没有改变丁硫醚的裂解反应历程。

The structure of sulfonated polys from DB is similar to that of sulfonated poly(arylene thioether phosphine oxide)s from TB. The latter could be regarded as the"product"of the former provided that the ether unit of the former was replaced by the thioether unit. The studies illustrated that the latter exhibited much better oxidative stability than the former. This is due to the fact that the thioether unit of the former was oxidized into the sulfone or sulfoxide unit in Fenton reagent, which inactivated the adjacent benzene rings and thus retarded the degradation reaction.

从结构上看，后者可以看成是前者的醚基团被硫醚基团取代后的&产物&，其耐氧化性能比前者好得多，这是因为后者的硫醚基团在Fenton试剂中被氧化成为砜或亚砜基团，而砜或亚砜基是钝化基团，钝化了与之相连的苯环，阻碍了降解反应。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。