N-芳(烷)磺酰基-N′-[1-氰(环)烷基]脲的合成与杀菌活性

磺酰脲类化合物是已知的超高效除草剂［１］，而取代的氨基乙腈类化合物又具有多种生物活性如杀菌和除草活性［２～５］。为了寻找新的具有生物活性的先导化合物，作者以取代的氨基乙腈基团替代已知磺酰脲结构中的嘧啶胺或三嗪胺，合成了如下通式（１）所示的１３个未见文...     

N′-(4,5,6-三取代嘧啶-2-基)-2-噻吩磺酰脲的合成

前文曾报道了15种含4,6—二取代嘧啶环的噻吩磺酰脲类化合物的合成和除草活性测定。初步的结构与生物活性关系的研究表明,嘧啶环上取代基的种类,数目及位置对此类化合物的生物活性影响较大,含4,6—二甲基嘧啶环的噻吩磺酰脲具超高除草活性,含4—羟基—6—甲基嘧啶环或4—氯—6—甲基嘧啶环的噻吩磺酰脲能有效抑制植物根系的生长,而含取代氨基的噻吩磺酰脲的生物活性较差。为进一步研究不同取代基对此类化合物生物活性的影响,本文合成了13种     

新磺酰脲类化合物的合成及生物活性

以正在开发的新磷磺酰脲除草剂N-[2′-(4′-甲基)嘧啶基]-2-硝基苯磺酰脲的研究为基础,设计合成了19个脲桥经修饰的磺酰脲类化合物以及3个新型嘧啶中间体,产物结构经¹HNMR谱及元素分析确证.盆栽试验和离休ALS酶研究结果表明,所合成的化合物均表现出一定的除草活性,部分化合物的除草活性较好.     

三嗪基三取代氨基甲酰脲的合成及其生物活性

以4,6-二烷氧基-2-三嗪基异氰酸酯和N,N-二取代脲为原料,合成了10个未见文献报道的标题化合物,其结构经1HNMR,IR和元素分析确证。初步生物活性测定表明,所有化合物均具有一定的除草活性。其中部分化合物具有明显的除草活性。     

新型吡唑甲酰脲类化合物的合成及其生物活性

５－氯－１，３－二甲基吡唑－４－甲酰基异氰酸酯同胺类化合物反应，合成了２３个新型吡唑甲酰脲类化合物，其化学结构经ＩＲ、１ＨＮＭＲ、ＭＳ和元素分析确证。所有化合物均具有一定的杀菌活性，部分化合物具有较好的杀虫活性。     

N,N,N′′-三取代氨基甲酰脲类化合物的合成

N，N－二取代脲和取代三氯乙酰胺反应合成了10种未见文献报道的标题化合物，产物结构经元素分析、IR和^1H NMR确证。初步生物活性测定表明多数化合物具有明显的除草活性。     

N-(4,6-二甲氧基嘧啶-2-基)-N'-磷酰基脲类衍生物的合成及生物活性

利用二氯代磷酰基异氰酸酯与4,6-二甲氧基-2-氨基嘧啶的加成反应合成了中间体N-(4,6-二甲氧基嘧啶-2-基)-N'-二氯代磷酰基脲(Ⅰ).Ⅰ与2倍的醇或胺反应得到对称双取代磷酰基脲类化合物Ⅱa_Ⅱi;Ⅰ与1倍的胺反应得到氯代磷酰基脲类化合物Ⅲa_Ⅲe,再与1倍的醇反应则得到不对称双取代磷酰基脲类化合物Ⅳa_Ⅳg.生物活性测定结果表明,化合物Ⅱ、Ⅲ和Ⅳ均显示一定除草活性.     

苯环2-位不同酯基取代的磺酰脲类化合物的合成及其除草活性

以正在开发的磺酰脲类超高效除草剂NK94827[N'-(4'-甲基嘧啶-2'-基)-2-甲氧羰基苯磺酰脲]的基本结构为基础,设计合成了18个苯环2位不同酯基取代的的新型磺酰脲类化合物,产物结构均经¹HNMR及元素分析确证.经油菜平皿法和盆栽试验测试除草活性,所合成的部分磺酰脲化合物的除草活性高.     

N-[4-氯-2-取代氨基甲酰基-6-甲基苯基]-1-芳基-5-氯-3-三氟甲基-1H-吡唑-4-甲酰胺的合成及生物活性

通过改变传统氯虫酰胺中吡唑环上氨基甲酰基与吡啶环之间的相对位置, 或以其它芳环取代原分子中的吡啶环, 设计合成了24个结构新颖的N-[4-氯-2-取代氨基甲酰基-6-甲基苯基]-1-芳基-5-氯-3-三氟甲基-1H-吡唑-4-甲酰胺类化合物. 所有目标化合物的结构均通过¹H NMR谱、 元素分析或高分辨质谱表征确定. 初步的生物活性测试结果表明, 部分化合物对东方粘虫具有较好的杀虫活性, 其中化合物6m在浓度为50 mg/L时具有80%的杀虫活性. 同时, 在浓度为50 mg/L时目标化合物对5种常见病菌具有明显的抑制作用, 其中化合物6n和6x对苹果轮纹菌的抑菌率达62.1%.     

N-(4,6-二取代嘧啶-2-基)-N'-(1-甲基-3-乙基-4-氯吡唑-5-基)甲酰基(硫)脲的合成及生物活性

利用活性结构拼接原理,将高效杀螨剂吡螨胺分子的吡唑环部分引入酰基（硫）脲化合物中,以1-甲基-3-乙基-4-氯-5-甲酸基吡唑和2-氨基-4,6-二取代嘧啶为起始原料,通过多步反应合成了5种N-（4,6-二取代嘧啶-2-基）-N’-（1-甲基-3-乙基-4-氯吡唑-5-基）甲酰基脲和5个N-（4,6-二取代嘧啶-2．基）-N’-（1．甲基-3-乙基-4-氯吡唑-5-基）甲酰基硫脲化合物,其化合物结构经IR、^1HNMR及元素分析测试技术确证。初步生物活性试验表明,在50mg／L质量浓度下目标化合物的杀螨活性不太理想,但有些化合物具有较好的除草活性,其中化合物Ib、Ic和Ie对稗草主根的生长抑制率大于60％。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.