N-烷基-N-酰基磺酰胺聚苯乙烯基微球作为固相酰化剂的研究

一种可循环使用的固相试剂：N-烷基-N-酰基磺酰胺聚苯乙烯基微球(5), 通过对聚苯乙烯磺酰氯微球树脂进行两步功能基化的修饰反应来制备. 制备过程如下：聚苯磺酰氯树脂(1)与伯胺(2)反应得到聚苯乙烯基N-烷基磺酰胺树脂(3), 树脂3用酰氯(4)或酸酐酰化得到N-烷基-N-酰基磺酰胺聚苯乙烯基树脂(5). 酰化的树脂5作为酰基转移试剂与亲核试剂胺反应得到二级酰胺. 根据5上取代基对酰胺生成的程度的影响结果表明, 烷基R¹和酰基(R²CO)对酰基转移反应活性的大小依次分别为：苯基＞苄基＞甲基＞正丁基＞＞H和对硝基苯甲酰基(苯甲酰基＞乙酰基. 胺的亲核能力对酰胺的收率也有一定的影响. N-苯基-N-苯甲酰基磺酰胺树脂重复使用3次没有发现活性降低.     

聚苯乙烯基N-甲基-N-酰基磺酰胺树脂的制备及其作为酰基转移试剂在酰胺合成中的应用

聚苯乙烯基磺酰氯树脂(树脂1)与甲胺水溶液在吡啶的催化作用下反应，制备了N—甲基磺酰胺树脂(树脂2)．用酰氯在吡啶中与树脂2反应，得到N—酰基—N—甲基磺酰胺树脂(树脂3)．树脂3作为胺底物的酰基转移试剂，用来制备N—取代的酰胺，收率14～81％．树脂3可以有选择性地酰化乙醇胺中的氨基而不会使羟基酰化。     

N-[(S)-脯氨酰]羟胺的合成及催化直接不对称羟醛反应研究

(S)-脯氨酸用苯甲氧羰酰氯保护氨基后用混合酸酐法与羟胺偶合, 给出N-[N-苯甲氧羰酰-(S)-脯氨酰]羟胺, 催化氢解脱去保护基得标题化合物. 该化合物对映选择性催化直接羟醛反应, 产率最高达到90.0%, 对映体过量最高达89.5%.     

N′-(取代嘧啶-2-基)-N-菊酰硫脲的合成与生物活性研究

采用活性基团拼接法, 将第一菊酸构型中的最高活性组分(＋)-反式菊酸以及二氯菊酸引入到含取代嘧啶环的酰基硫脲结构中, 合成了5个未见文献报道的N′-(取代嘧啶-2-基)-N-(＋)-反式菊酰硫脲衍生物(3a～3e)和3个均未见文献报道的N′-(取代嘧啶-2-基)-N-二氯菊酰硫脲(3f～3h), 结构经元素分析、IR和¹H NMR得到确证. 初步的生物活性测试结果表明: 大部分化合物具有较好的杀菌活性, 有的化合物兼具除草和杀菌活性, 有的化合物兼具杀虫和杀菌活性.     

D-呋喃核糖长链酰基衍生物的合成及生物活性研究

以N,N-二环己基碳二亚胺(DCC)作缩水剂, 使D-氨甲基呋喃核糖、苯甲酰氨基甲基呋喃核糖与长链脂肪酸发生缩合, 得到8个新型D-呋喃核糖的长链酰基衍生物, 通过波谱分析对其结构进行了确证. 并用噻唑蓝(MTT)法考察了所合成化合物对小鼠T-淋巴细胞增殖反应的影响. 结果显示: 长链酰基取代后的化合物4a～4d和5a～5d对小鼠T-淋巴细胞增殖的抑制活性明显优于未取代的底物2和3.     

N-[3-氰基-1-(2,6-二氯-4-三氟甲基苯基)-1H-吡唑-5-基]菊酰胺类化合物的合成及生物活性

为了寻求新的N-芳基吡唑类先导化合物, 用5种拟除虫菊酯类农药的活性基团——菊酸与高活性杀虫剂氟虫腈和其中间体5-氨基-3-氰基-1-(2,6-二氯-4-三氟甲基-苯基)吡唑在其氨基位置采用亚结构对接的方法合成得到了10个新的芳基吡唑菊酰胺类化合物. 经¹H NMR, ESI-MS和元素分析对化合物的结构进行了表征. 初步生物活性测定结果表明, 在37.5 mg/L浓度下, N-[3-氰基-1-(2,6-二氯-4-三氟甲基苯基)-4-(三氟甲基亚磺酰基)-1H-吡咯-5-基]-3-(2,2-二氯乙烯基)-2,2-二甲基环丙酰胺(3b)对小菜蛾Amaranthus spinosus抑制活性达到100%, LC₅₀为15.1 mg/L. 初步雌雄大鼠急性经口毒性综合评价属中毒级, 同时还检测了2-(4-氯苯基)-N-[3-氰基-1-(2,6-二氯-4-三氟甲基苯基)-1H-吡唑-5-基]-3-甲基丁酰胺(3i)的晶体结构.     

一步法合成N-1,3-二羟基丙烷-2-基烷基乙酰胺

以5-氨基烷基-2,2-二甲基-1,3-二噁烷为起始原料, 乙酸酐为酰化剂, 一步法选择性地合成氨基二醇类氨基乙酰化产物N-1,3-二羟基丙烷-2-基烷基乙酰胺. 该方法操作简便, 收率高. 所合成的4个新化合物的结构均经FTIR, ¹H NMR, ¹³C NMR及HRMS确证. N-3-(1,3-二羟基丙烷-2-基)丙基乙酰胺(1a)作为关键的中间体, 可以用于HIV-1 Tat/ PCAF BRD抑制剂4的合成.     

4-(取代嘧啶-2-基)-1-芳磺酰基氨基脲化合物的合成与表征

以取代的苯磺酰肼与(取代嘧啶-2-基)-氨基甲酸苯酯在非亲核性碱存在下合成了12个4-(取代嘧啶-2-基)-1-芳磺酰基氨基脲化合物5和3个5与碱形成的有机盐5as, 5bs和5cs. 所有合成化合物均经过元素分析和¹H NMR的结构确证. ¹H NMR数据证明, 在5as～5cs中, 磺酰氨基脲起到提供质子的作用.     

光学活性化合物多羟基庚酸乙酯的合成

以不对称环氧化和双羟化反应为构筑手性碳的关键步骤, 首次合成了(＋)-(2R,3S,4S,5S)-6-甲基-4,5-环氧-2,3-二羟基-庚酸乙酯(5)和(－)-(2R,3S,4R,5S)-6-甲基-2,3,4,5-四羟基-庚酸乙酯(11). 找到一条适宜于该类化合物合成的简便有效且立体选择性好的合成路线. 初步生物活性测试表明, 化合物5, 11对HL60细胞具有抑制活性.     

α-亚胺酮的不对称转移氢化合成(R)-沙丁胺醇

用手性(S,S)-Ru-TsDPEN催化剂不对称转移氢化α-亚胺酮化合物5-[(1,1-二甲基乙基)亚胺基]乙酰基-2-羟基苯甲酸甲酯(2)得光学纯β-氨基芳基乙醇类化合物(R)-5-[2-[(1,1-二甲基乙基)氨基]-1-羟乙基]-2-羟基苯甲酸甲酯(3), 再经一步还原反应即得(R)-(－)-沙丁胺醇. 对反应关键一步α-亚胺酮的不对称转移氢化反应条件进行了研究.     

Preparation of Polystyrene-supported N-phenyl-N-acyl Sulfonamide Resin and its Application in Solution-phase Synthesis of Amides

Polystyrene-supported N-phenyl-N-acyl sulfonamide resin was prepared by reacting polystyrene sulfonyl chloride resin with aniline and acylating in pyridine with either acid chlorides or anhydrides. Then, this resin was utilized as a new type of acyl transfer reagent to synthesize the amide library. It was approved to be a more effective acyl transfer reagent with higher amide yields than the polystyrene-supported N-methyl-N-acyl sulfonamide resin and N-benzyl-N-acyl sulfonamide resin. When the phenyl group bonded to the N atom on N-phenyl-N-acyl sulfonamide resin was substituted by the electron withdrawing group or electron donating group, a decreasing amide yield was obtained. N-phenyl-N-acyl sulfonamide resin could be regenerated many times.     

Soluble polymer bound cleavage reagents: a multipolymer strategy for the cleavage of tertiary amines from REM resin

Soluble polymer bound reagent 1 has been prepared to cleave tertiary amines from REM resin. Normally, amines cleaved from REM resin require extraction or chromatography to remove excess cleavage reagent and its byproducts. The solubility profile of non-crosslinked polystyrene (NCPS) based reagent 1 eliminates the need for such purification and allows for the direct isolation of a library of pure tertiary amines through simple filtration and concentration operations.     

Peptide synthesis in water IV. Preparation of N-ethanesulfonylethoxycarbonyl (Esc) amino acids and their application to solid phase peptide synthesis

A new N-protecting group, ethanesulfonylethoxycarbonyl (Esc), was designed to perform peptide synthesis in both aqueous and organic solvents. Esc-amino acids were prepared by the reaction of Esc-Cl and amino acids. Although Esc-Cl was a highly reactive reagent, it was not stable and decomposed during the purification procedure. A more stable reagent, ethanesulfonylethyl-4-nitrophenyl carbonate (Esc-ONp), was designed for preparation of Esc-amino acids. Esc-ONp was a stable reagent and could be purified by silica gel column chromatography or recrystallization. Esc-amino acids were prepared by the reaction of Esc-ONp and amino acids in good yield. To evaluate Esc-amino acids, Leu-enkephalin amide was synthesized using Esc-amino acids by the solid phase method in water. Removal of the Esc group was performed with 0.025 mol/l NaOH in 50% aqueous ethanol. Leu-enkephalin amide was successfully synthesized on a poly(ethylene glycol)-grafted polystyrene resin. Esc-amino acids have moderate solubility in organic solvents (such as dimethylformamide and acetonitrile). Leu-enkephalin amide was synthesized using Esc-amino acids by the solid phase method in dimethylformamide. Removal of the Esc group was performed with 0.05 mol/l tetrabutylammonium fluoride in dimethylformamide. Synthesis of Leu-enkephalin amide using Esc-amino acids in dimethylformamide was also successful. The yields of synthesis of Leu-enkephalin amide in water and dimethylformamide were 71% and 67%, respectively.     

Synthesis of new 3'-, 5-, and N(4)-modified 2'-O-methylcytidine libraries on solid support

A versatile solid phase combinatorial approach was developed and utilized for the rapid synthesis of new 2'-O-methylcytidine nucleoside libraries 1-7 containing 672 compounds with 3'-deoxy-3'-C-methyl, 3'-deoxy-3'-C-hydroxymethyl, and 5-alkyl/alkynyl modifications. The modified uridine scaffolds 8-10, 23-25, and 31 were loaded onto the 4-methoxytrityl chloride (MMT-Cl) polystyrene resin through the hydroxyl groups at the 5'-position as well as on the substituents at the 3'- and 5-positions. The scaffolds loaded on the resin were orthogonally protected by MMT group on the resin itself and TBDMS or acetyl protecting groups. The 4-position of the uridine derivatives was activated by 2,4,6-triisopropyl benzene sulfonyl chloride for further derivatization. The resins 14-16, 28-30, and 32 loaded with the corresponding activated scaffolds were reacted with the selected and validated amino building blocks in the 96 well format on the semiautomated synthesizer. The high-quality 2'-O-methylcytidine libraries 1-7 were thus generated and characterized by liquid chromatography-mass spectrometry (LC-MS) analysis with 63-99% successful rates.     

Polystyrene‐modified novolac epoxy resin/clay nanocomposite: Synthesis,and characterization

A polystyrene‐modified epoxidized novolac resin/montmorillonite nanocomposite was fabricated and characterized successfully. For this purpose, novolac resin (NR) was epoxidized through the reaction of phenolic hydroxyl group with epichlorohydrin in super basic medium to produce epoxidized novolac resin (ENR). Afterward, a polystyrene was synthesized by atom transfer radical polymerization (ATRP) technique, and then brominated at the benzylic positions using N‐bromosuccinimide (NBS). The brominated polystyrene (PSt‐Br) was reacted with ethanolamine in basic medium in order to afford an amine‐functionalized polystyrene (PSt‐NH₂). An organo‐modified montmorillonite (O‐MMT) was synthesized through the treatment of MMT with hexadecyl trimethyl ammonium chloride salt. Finally, ENR‐PSt/MMT nanocomposite was fabricated through curing a mixture of ENR (70 wt.%) and O‐MMT (5 wt.%) with PSt‐NH₂ (25 wt.%). Transition electron microscopy (TEM) and powder X‐ray diffraction (XRD) analysis revealed that the fabricated nanocomposite has an exfoliated structure. Thermal property studies using thermogravimetric analysis (TGA) showed that the curing of ENR by PSt‐NH₂, as well as incorporation of a small amount of MMT have synergistic effect on the thermal stability of the ENR resin.     

A novel linker for solid-phase synthesis cleavable under neutral conditions

A novel linker cleavable under neutral conditions has been developed for the solid-phase synthesis of base-labile compounds. The linker is comprised of a 3-azidomethyl-4-hydroxybenzyl alcohol moiety, and the azidomethyl group in the linker is readily converted to an aminomethyl group by treatment with a phosphine reagent in the presence of water to result in an intramolecular cyclization to release the compounds. Using the linker, a base-labile dinucleoside methyl phosphate was synthesized on a highly cross-linked polystyrene (HCP) support and cleaved successfully from the resin without decomposition of the product.     

Synthesis of a Fluorescent‐Labeled Bisbenzamidine Containing the Central (6,7‐Dimethoxy‐4‐coumaryl)Alanine Building Block

The synthesis of an amino acid amide is reported, which contains two benzamidine cores, one placed in the amide part the other one within the sulfonyl N‐capping group. The amino acid side chain bears the 6,7‐dimethoxycoumarin fluorophore. The fluorescent amino acid was prepared by using the von‐Pechmann reaction. The two corresponding nitrile groups of a precursor molecule were simultaneously converted to the amidine moieties by the Pinner reaction. The fluorescent properties of the final compound were determined.     

Fragmentation pathways of deprotonated amide‐sulfonamide CXCR4 inhibitors investigated by ESI‐IT‐MSn,ESI‐Q‐TOF‐MS/MS and DFT calculations

Amide‐sulfonamides provide a potent anti‐inflammatory scaffold targeting the CXCR4 receptor. A series of novel amide‐sulfonamide derivatives were investigated for their gas‐phase fragmentation behaviors using electrospray ionization ion trap mass spectrometry and quadrupole time‐of‐flight mass spectrometry in negative ion mode. Upon collision‐induced dissociation (CID), deprotonated amide‐sulfonamides mainly underwent either an elimination of the amine to form the sulfonyl anion and amide anion or a benzoylamide derivative to provide sulfonamide anion bearing respective substituent groups. Based on the characteristic fragment ions and the deuterium–hydrogen exchange experiments, three possible fragmentation mechanisms corresponding to ion‐neutral complexes including [sulfonyl anion/amine] complex ( INC‐1 ), [sulfonamide anion/benzoylamide derivative] complex ( INC‐2 ) and [amide anion/sulfonamide] complex ( INC‐3 ), respectively, were proposed. These three ion‐neutral complexes might be produced by the cleavages of S–N and C–N bond from the amide‐sulfonamides, which generated the sulfonyl anion (Route 1), sulfonamide anion (Route 2) and the amide anion (Route 3). DFT calculations suggested that Route 1, which generated the sulfonyl anion (ion c ) is more favorable. In addition, the elimination of SO₂ through a three‐membered‐ring transition state followed by the formation of C–N was observed for all the amide‐sulfonamides.     

Anthraquinone-2-sulfonyl chloride: a new versatile derivatization reagent-synthesis mechanism and application for analysis of amines

A new sulfonating agent, anthraquinone-2-sulfonyl chloride, has been synthesized. The reagent consists of three important moieties: a cyclic conjugation system (with 18 pi-electrons), a p-quinone system and a group of sulfonyl chloride and is thereby a versatile derivatization reagent for analytical chemistry. The mechanism about the synthetic reaction was first elucidated in aid of mass spectrometry. Several primary and secondary amines were selected to evaluate the new reagent and their standard derivatives were prepared via a facile pathway. Analytical derivatization carried on through a one-step procedure at room temperature within 3 min. The new reagent reacts quantitatively with amines to form stable sulfonamides, which are readily amenable to analysis by normal-phase and reversed-phase HPLC. Compared with standard derivatives, excellent response linearity is demonstrated over the concentration range 0.4-400 muM at 320 nm for normal-phase HPLC and 4 nM to 4 muM at 256 nm for reversed-phase HPLC. Detection limits are 0.8 nmol and 8 pmol, respectively.