含席夫碱基的螺噁嗪类光致变色化合物的合成及性质

设计合成了一系列含席夫碱基的螺噁嗪双功能光致变色材料4a~4d. 通过¹H NMR, ¹³C NMR, IR和HRMS对其结构进行了表征. 新化合物在几种有机溶剂中均表现出了良好的光致变色性. 研究了化合物在几种高分子膜中的光致变色性. 比较了化合物4b的开环体在两种不同溶剂, 即甲醇和二甲亚砜, 以及3种高分子介质, 即聚甲基丙烯酸甲酯(PMMA)、聚乙烯醇缩丁醛(PVB)和聚乙烯醇(PVA)中的消色速率. 研究了化合物在甲醇、二甲亚砜、PMMA及PVB中的消色过程动力学, 根据化合物在溶液中和高分子介质中开环体消色过程的差别, 推测了存在两种动力学解释的原因. 研究结果显示, 化合物4d在PMMA膜中的耐疲劳度良好.     

含席夫碱基的螺吡喃双功能光致变色材料的合成及性质

设计合成了一系列含席夫碱基的螺吡喃双功能光致变色材料4a~4n. 通过1H NMR, IR和HRMS对其结构进行了表征. 研究了化合物在几种溶剂和PMMA膜中的光致变色性质, 研究了化合物4a在甲醇中, 以及化合物4a和4f在高分子介质聚甲基丙烯酸甲酯(PMMA)中的消色过程. 结果表明, 化合物4e在PMMA膜中光照后呈现出与其它化合物不同的颜色, 为罕见的绿色. 化合物4a在二氯甲烷溶液中有良好的荧光性能. 所合成的新型含席夫碱基的螺吡喃双功能光致变色材料在甲醇、二氯甲烷和环己烷溶液中及在PMMA膜中均表现出良好的光致变色性质.     

含BOC保护基团的螺吡喃类化合物的合成及其光致变色性能的研究

合成了5-[N-(叔丁氧甲酰基)氨基]-1,3,3-三甲基-6′-硝基吲哚啉螺吡喃(BOCSPI)和5-[N-(叔丁氧甲酰基)氨基]-1,3,3-三甲基-6′-硝基-8′-甲氧基吲哚啉螺吡喃(BOCSPII)两种光致变色化合物,采用紫外-可见光谱法研究了其在溶液和以不同质量比掺杂在聚甲基丙烯酸甲酯(PMMA)膜中的光致变色性能.研究表明螺吡喃的高掺杂量不利于其开环和闭环态的转化,BOCSPII分子中的甲氧基有利于有色开环体的部花菁的稳定.     

基于烯胺腈结构的吡喃香豆素并嘧啶类化合物的合成及抗肿瘤活性研究

吡喃香豆素是一类重要的天然产物,具有广泛的生物活性和药理作用,如抗肿瘤、抗菌、抗人类免疫缺陷病毒(HIV)、抗炎、抗氧化等.嘧啶是另一类重要的含氮杂环化合物,利用药物设计中的药效团拼合原则,如将吡喃香豆素和嘧啶结构进行拼合,有可能获得抗肿瘤活性更好的先导化合物.因此,首先以4-羟基香豆素、芳香醛、丙二腈为原料,4-二甲氨基吡啶(DMAP)为催化剂,通过多组分反应合成具有烯胺腈结构的吡喃香豆素,再与N,N-二甲基甲酰胺二甲缩醛(DMF-DMA)反应制备N,N-二甲基甲脒,最后与芳香胺通过Dimroth重排制备新型4-苯胺基取代吡喃香豆素并嘧啶类化合物,并通过熔点,IR,1H NMR,13C NMR,元素分析对目标产物的结构进行了表征,所得目标产物均未见文献报道.该方法具有反应时间短、反应条件温和、操作简单、产率高、无需柱色谱分离等优点.通过四甲基偶氮唑盐微量酶反应比色法(MTT)对目标产物抑制人宫颈癌细胞Hela和人急性早幼粒白血病细胞HL-60的活性进行了体外评价,结果表明:化合物4-(4'-溴苯胺基)-5-(2',3'-二氯苯基)-色烯[3',4':5,6]吡喃[2,3-d]嘧啶-6-酮(4k)和4-(4'-溴苯胺基)-5-(4'-硝基苯基)-色烯[3',4':5,6]吡喃[2,3-d]嘧啶-6-酮(4l)对HL-60具有较高活性,其IC50分别为(11.3±0.3)和(10.8±0.2)μmol/L;化合物4-(4'-氯苯胺基)-5-(3',4',5'-三甲氧苯基)-色烯[3',4':5,6]吡喃[2,3-d]嘧啶-6-酮(4g)和4-(3'-氯-4'-氟苯胺基)-5-(3',4',5'-三甲氧苯基)-色烯[3',4':5,6]吡喃[2,3-d]嘧啶-6-酮(4h)对Hela具有较高活性,其IC50分别为(9.2±0.6)和(8.5±0.2)μmol/L.     

一种新型双缩合螺吡喃的合成、表征及晶体结构

以过量吲哚啉和5-硝基水杨醛为原料合成了4-(2-亚甲基-1-乙基-3,3-二甲基吲哚啉-2'-基)-6-硝基-1'-乙基-3',3'-二甲基-螺[3,4-二氢-2H-l-苯并吡喃-2,2'-吲哚啉],通过核磁共振、红外光谱、元素分析对其结构进行了表征.同时利用X单晶衍射仪测定了该化合物的结构,结果表明:晶体属单斜晶系,空间群P21/n,a=1.2476(3)nm,b=1.1939(2)nm,c=2.0317(4)nm,α=90°,β=107.45(3)°,γ=90°,Dc=1.205g/cm3,μ=0.077mm-1,F(000)=1120,V=2.8871(10)nm3,Z=4.     

一种吲哚螺吡咯多取代杂环化合物的合成及其晶体结构

利用多组分1,3偶极环加成反应方法,合成了一种新的螺环结构1'-甲基-3'-吡啶甲酰基-4'-(2-噻吩基)螺[吲哚啉-3,2'-吡咯啉]-2-酮化合物,并对该化合物进行了红外光谱、核磁共振谱及X-射线单晶衍射表征.单晶衍射结果表明:该晶体属于三斜晶系,空间群为P-1,晶体参数为a=0.899 9(1)nm,b=0.914 4(1)nm,c=1.271 1(2)nm,α=92.852(1)°,β=107.305(2)°,γ=101.580(1)°.在分子晶体结构中,吡咯啉环采用了信封式构象,通过螺碳原子与吲哚啉环相连,形成刚性螺环结构,2个环接近垂直构型,其二面角为84.15(2)°.     

聚乙二醇支载的螺吡喃类光致变色化合物的合成及其逆光致变色性质

采用DCC缩合的方法,将吲哚啉螺苯并吡喃的衍生物和聚乙二醇相缩合,以聚乙二醇末端的羟基和吲哚啉螺苯并吡喃衍生物的羧基为反应活性基团,实现了带有羧基的螺吡喃类光致变色化合物支载到了聚乙二醇两端.通过引入亲水基团得到了水溶性较好的螺环类光致变色化合物.通过对产物的紫外-可见光谱的研究发现,产物具有良好的光致变色性质,在乙醇、丙酮和乙酸乙酯中皆具有良好的光致生色现象;产物可溶于水,在紫外光(波长365nm)照射时产生了光消色现象,具有明显的逆光致变色性质.该方法原料易得,反应条件容易控制,为光致变色新材料的研究和开发提供了新方法.     

吡喃羟丙基纤维素的合成与光响应性研究

以N,N'-二环己基碳二亚胺/4-二甲氨基吡啶(DCC/DMAP)为催化体系,在四氢呋喃溶剂中,常温下1'-(3-羧乙基)-3',3'-二甲基-6-硝基螺[吲哚啉-2,2[2H]吲哚啉苯并吡喃](SPCOOH)与羟丙基纤维素(HPC)发生酯化反应,合成了螺吡喃羟丙基纤维素SP-HPC.通过改变SPCOOH与HPC的重量比,可以制备含有不同螺吡喃(SP)取代度(DSsp)的SP-HPC.当SPCOOH/HPC为1.5时,DSsp达到最大值1.08.SP-HPC溶解在THF中,经紫外光照射后,闭环的SP逐渐开环转变为部花菁式(MC)大共轭结构,溶液由无色逐渐变为深紫色;当溶液又置于完全黑暗环境时,开环的MC又逐渐闭环回复到SP形式,溶液又变为无色.溶液中的SP-HPC显示了快速可逆的紫外光响应特性.由于SP基团的疏水性,使得SP-HPC在水溶液中自组装为球形胶束.SP-HPC胶束显示了光响应性,闭环形式的SP吸收紫外光转变为开环形式MC,MC的大共轭结构导致基团间发生更紧密地堆叠,促使球形胶束收缩.SP-HPC固体膜显示了可逆的紫外光响应性,但是MC转化为SP的光响应速度比由SP吸收能量转化为MC的速度慢得多.     

新型双螺噁嗪分子的合成及性能

设计合成了3个双螺噁嗪化合物, 采用核磁共振谱、红外光谱和高分辨质谱对这些化合物进行了表征. 测试了光照前后化合物在不同溶剂中的紫外吸收光谱、荧光光谱以及在高分子薄膜中的消色动力学曲线. 结果表明, 目标化合物均具有良好的光致变色性能和耐疲劳度, 在材料、分子开光及生物探针领域有潜在的应用前景.     

超声辐射下合成含苯并噻喃片段的新颖螺吲哚类化合物及其抗真菌活性

探索了一种快速、高效的超声合成方法,通过三组分一锅法合成了20个2'-氨基-2-氧代-5'H-螺[吲哚啉-3,4'-苯并噻喃[4,3-b]吡喃]-3'-甲腈类结构新颖的螺吲哚化合物.所得到的化合物均由1H NMR,13C NMR和HRMS确证.研究了超声对产率和反应时间的影响.采用微量稀释法对所合成的化合物进行了抗真菌活性的测定.其中,化合物4f对新生隐球菌、絮状表皮癣菌和总状毛霉的抑制活性均优于阳性对照药物氟康唑.     

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.