一锅法合成1,4-二(2,2'-二吡咯甲基)苯

以吡咯和对苯二甲醛为原料,采用无溶剂Michael加成反应一步合成1,4-二(2,2'-二吡咯甲基)苯(BDMP)。考察了投料比、温度、催化剂等因素对反应的影响。得出合成的最佳工艺条件为:n(吡咯)∶n(对苯二甲醛)∶n(丙酸)=4∶1∶0.1,反应温度25℃,反应时间30min。在此条件下,产品1,4-二(2,2'-二吡咯甲基)苯的收率可达85%,纯度可达95%(HPLC)。目标化合物经1HNMR、13CNMR确证。     

二乙酰基吡咯的合成

吡咯转化为吡咯钾与对甲基苯磺酰氯反应,得1 对甲基苯磺酰基吡咯(Ⅰ),产率61 0%,熔点105～106℃;n(Ⅰ)∶n(乙酸酐)=1 0∶1 15,在室温下反应2h,得1 对甲基苯磺酰基 2 乙酰基吡咯(Ⅱ),产率80 5%,熔点110～111℃;Ⅱ在碱性溶液中水解,得2 乙酰基吡咯(Ⅲ),产率为94 4%,熔点89～90℃;Ⅲ与冰乙酸在室温下反应14d,得2,5 二乙酰基吡咯(产率16 2%,熔点158～159℃)和2,4 二乙酰基吡咯(产率45 1%,熔点137～138℃)。通过核磁共振、红外光谱和元素分析验证了产品的结构。     

2,2-二羟甲基十二酸的合成

研究了以月桂醛(正十二醛)、甲醛、过氧化氢为原料,经羟醛缩合、过氧化氢氧化合成2,2-二羟甲基十二酸的方法,探讨了原料摩尔比、催化剂或氧化剂用量、反应温度和时间对羟醛缩合反应和氧化反应的影响。结果表明,月桂醛(正十二醛)与甲醛摩尔比为2.6∶1.0、催化剂与月桂醛摩尔比为0.51∶1.0、羟醛缩合反应温度为50℃、反应时间为3 h,合成的2,2二-羟甲基十二醛收率为46%;H2O2与2,2二-羟甲基十二醛摩尔比为1.1∶1.0,氧化反应温度为70℃、反应时间为7 h,合成的2,2二-羟甲基十二酸收率为86%。并用13C和1H核磁共振谱表征了2,2-二羟甲基十二酸的结构。     

2,5-二甲基对苯二甲腈α-位溴代反应

用N-溴代丁二酰亚胺(NBS)作溴化剂,以2,5-二甲基对苯二甲腈为原料,合成了目标化合物2,5-二溴甲基对苯二甲腈。用正交设计实验对影响2,5-二甲基对苯二甲腈生成2,5-二溴甲基对苯二甲腈的溴代反应条件进行了考察,最佳反应条件为:n(2,5-二甲基对苯二甲腈)∶n(NBS)=1∶2.1,反应温度80℃,2,5-二甲基对苯二甲腈浓度0.1 mol/L,反应时间16 h,产率可达31.4%。溴代粗品经反相柱色谱分离〔洗脱液:V(甲醇)∶V(水)=70∶30〕,洗脱组分分别是2-甲基-5-溴甲基对苯二甲腈、2,5-二溴甲基对苯二甲腈、2-甲基-5-(1,1-二溴)甲基对苯二甲腈与2-溴甲基-5-(1,1-二溴)甲基对苯二甲腈。     

2,2'-二氨基联苄的合成研究

以邻硝基氯苄为起始原料,经缩合和还原得到2,2'-二氨基联苄,探索了反应的影响因素。结果表明,2,2'-二硝基联苄较佳合成条件为:n(邻硝基氯苄)∶n(金属钠)=1∶2,回流,反应7 h,收率85.00%,HPLC纯度97.32%;2,2'-二氨基联苄的较佳合成条件:n(2,2'-二硝基联苄)∶n(Fe)=1∶7,采用水与无水乙醇混合溶剂,V(水)∶V(乙醇)=2∶1,反应时间4 h,反应温度90℃,收率97.50%,HPLC纯度98.86%。产品结构经1H NMR、13C NMR和LC-MS分析表征确认。     

手性2,2’-双二苯基膦基-1,1’-联萘的合成

以(S)-(-)-1,1'-联萘-2,2'-二酚为原料,经三氟甲基磺酸基保护后与二苯基氧膦偶联,最后经三氯硅烷还原得到(S)-(-)-2,2'-双二苯基膦基-1,1'-联萘,采用~(31)PNMR、~1HNMR和HRMS对目标化合物进行结构表征,通过考察各步的反应条件,得出最佳的工艺条件:n〔(S)-(-)-1,1'-联-2-萘酚二(三氟甲磺酸酯)〕∶n(二苯基氧膦)∶n(1,4-二氮杂二环[2.2.2]辛烷)∶n〔Ni(dppe)Cl_2〕∶n(HSiCl_3)=1∶2.1∶2.5∶0.1∶3,在催化偶联步骤反应温度为100℃,反应时间为48 h,三氯硅烷还原步骤加热回流5 h,得到手性2,2'-双二苯基膦基-1,1'-联萘的收率可达82.3%,e.e.值为99.3%。     

2-丁炔-1,4-二苯合成工艺研究

以2-丁炔-1,4-二(对甲苯磺酸酯)为起始原料,在AlCl3催化下和苯发生傅-克烷基化反应,合成2-丁炔-1,4-二苯。考察了AlCl3和磺酸酯的物质的量比、溶剂种类和用量、反应时间、反应温度对产物收率的影响,确定适宜的反应条件如下:n(AlCl3)∶n(磺酸酯)∶n(苯)为2.6∶1∶2.8、反应时间为2h、反应温度为40℃,在此条件下,2-丁炔-1,4-二苯收率为60.1%。产物经元素分析、IR和1HNMR确证。     

除草剂2,6-二氟苯胺的合成

以 2 ,6 -二氟苯酰胺、氯气和氢氧化钠为原料 ,采用苯甲醇为反应介质 ,经Hofmann酰胺降级反应 ,制得 2 ,6 -二氟苯胺。其最佳工艺条件为 :n(酰胺 )∶n(氢氧化钠 )∶n(氯气 )∶n(苯甲醇 ) =1∶8 5 6∶1 2 3∶2 19,产品收率可达 92 % ,纯度可达 90 %     

固体光气法合成5-叔丁基-1,3,4-噁二唑-2(3H)-酮

研究了以特戊酸甲酯为原料,用固体光气代替光气两步合成标题化合物,为该中间体的合成提供了一条环境友好的新途径。考察了反应温度、物料配比及反应时间对第一步产物2,2-二甲基丙酸肼合成收率的影响,确定最佳工艺条件为:反应温度为90℃,n(水合肼)∶n(特戊酸甲酯)=1.5∶1,反应时间28 h;采用正交法考察了反应温度、物料配比、缚酸剂用量对标题化合物合成收率的影响,结果表明,最佳反应条件:以甲苯作溶剂,碳酸氢钠作缚酸剂,反应温度为80℃,n(2,2-二甲基丙酸肼)∶n(固体光气)∶n(碳酸氢钠)=1∶1.5∶0.35,在此最佳工艺条件下,收率可达94.88%。目标化合物经质谱、核磁氢谱验证。     

1,2-二（N-（4-硝基-邻苯二甲酰亚胺)）甲基碳硼烷的合成及其紫外吸收性质

以4-硝基邻苯二甲酰亚胺、1,4-二氯-2-丁炔和十硼烷为原料,通过取代反应和炔加成反应合成了1,2-二[N-(4-硝基-邻苯二甲酰亚胺)甲基]碳硼烷(4-NP CBR)。考察了反应溶剂、原料物质的量之比和反应温度对反应的影响,得到的优化条件为:甲苯为反应溶剂,n{1,4-二[N-(4-硝基-邻苯二甲酰亚胺)]-2-丁炔)}∶n(乙腈硼烷)=1.2∶1,100℃下加热反应16 h,在该条件下,1,2-二[N-(4-硝基-邻苯二甲酰亚胺)甲基]碳硼烷的产率为51.2%。产物通过FTIR、~1HNMR、~(13)CNMR和HR-MS进行结构表征,并测定了其紫外吸收性质。     

Production of 2-phenylethanol in hybrid system using airlift reactor and immersed hollow fiber membrane module

To minimize capital and operative costs in many bioproductions of chemical specialities, where the product inhibits the bioreaction, a hybrid system based on the application of membrane extraction integrated in the bioreactor to remove the product is a suitable solution. Integration can be done by an external module for membrane extraction or, as a more effective solution, by an extraction membrane module immersed directly in the bioreactor. In this second case, it is not necessary to use microfiltration to prevent membrane fouling or to use another pump for shell flow in the membrane module. Moreover, the system is very compact, highly effective, resistant to failures and its mathematic simulation is also possible. These statements are proved in this paper where a hybrid system consisting of an airlift reactor and immersed extraction hollow fiber membrane module was used for the biotransformation of l-phenylalanine to the desired rose-like aroma, 2-phenylethanol, by yeasts Saccharomyces cerevisiae. Two biotransformation experiments were carried out using different feeding and aeration strategies. In both experiments, high conversion of l-phenylalanine (up 100%) and high volumetric production of 2-phenylethanol (up 18.6 g L⁻¹) were reached. Both biotransformation experiments were mathematically predicted with good agreement between experimental data and simulations.     

Conformation–function relationships for the comb-shaped polymer pOEGMA

Poly(oligo(ethylene glycol) methyl ether methacrylate) (pOEGMA) is a highly versatile polymer because manipulation of the dimensions of its comb-type structure has a predictable effect on the conformation of its main-chain and side-chains which can, together or independently, be either extended or collapsed. This control, and the distinctive physical–chemical characteristics of pOEGMA, are the common driving forces behind its tunable thermosensitivity properties, supramolecular assembly characteristics, and efficient protein repellency. Because of these interesting properties, pOEGMA is increasingly being used within functional coatings, biosensors, drug delivery systems, biomaterials, etc. This Trend article highlights the how to control (and factors influencing) pOEGMA main/side-chain conformations, and consequently exploit this polymer in several emerging areas of importance. This discussion integrates all current areas of application (i.e., in solution, within complex (bio)conjugates, and grafted to solids), in order to provide a common and general perspective on how this polymer can be most efficiently used in future applications.     

对煤泥水处理流程中小循环的分析

以离心机脱水作业和浮选精煤加压过滤作业的小循环为案例,推导循环系数计算式,定量确定了离心液和滤液的浓度与循环负荷之间的关系,指出了小循环对选煤生产的影响;介绍了"2+2"模式煤泥水处理流程的特点,采用该流程彻底消除了选煤生产中的小循环。     

“2+3”提高采收率技术在靖安油田的应用

靖安油田位于鄂尔多斯盆地,现已进入开发中后期,针对其油藏产油量递减速度快,含水率急剧上升,开发效果变差等问题,选取“2+3”提高采收率技术对注水井进行调剖,使其对应油井达到稳产增产的目的,并指出该油田应用“2+3”采油技术的有利条件和改进措施.     

CO2的电驱动还原

CO₂的过量排放已威胁到了环境与能源的可持续发展,通过化学或生物手段将其转化为化工原料或生物燃料能够有效缓解由CO₂过量排放造成的能源与环境压力。然而CO₂的还原过程是非自发且缓慢的,依赖于外部提供的能量和催化剂。如何实现长效的能量供给并针对性开发高性能的催化剂是CO₂回收转化技术的重点。利用稳定、清洁的电能作为驱动力,在催化剂的协同下将CO₂增值为化学品并实现碳中性循环。这种策略被称为CO₂的电驱动还原,在CO₂转化方面优势显著。从CO₂无机电催化和CO₂微生物电合成2个方面综述了近年来CO₂电驱动还原的研究进展。首先,对比和讨论了CO₂的无机电催化中不同类型的电催化剂的特性,以及优化和改性的手段。其次,总结阐明了微生物电合成中电极与微生物催化剂之间直接和间接的电子传递方式,并重点讨论了不同电子载体（H₂、甲酸、天然和人工的氧化还原电子载体）介导的间接电子传递的相关工作。最后总结展望了CO₂电驱动还原系统的发展。     

Downregulation of lncRNA PpL-T31511 and Pp-miRn182 Promotes Hydrogen Cyanamide-Induced Endodormancy Release through the PP2C-H2O2 Pathway in Pear (Pyrus pyrifolia)

Bud endodormancy is an important, complex process subject to both genetic and epigenetic control, the mechanism of which is still unclear. The endogenous hormone abscisic acid (ABA) and its signaling pathway play important roles in the endodormancy process, in which the type 2C protein phosphatases (PP2Cs) is key to the ABA signal pathway. Due to its excellent effect on endodormancy release, hydrogen cyanamide (HC) treatment is considered an effective measure to study the mechanism of endodormancy release. In this study, RNA-Seq analysis was conducted on endodormant floral buds of pear (Pyrus pyrifolia) with HC treatment, and the HC-induced PP2C gene PpPP2C1 was identified. Next, software prediction, expression tests and transient assays revealed that lncRNA PpL-{"type":"entrez-nucleotide","attrs":{"text":"T31511","term_id":"613609"}}T31511-derived Pp-miRn182 targets PpPP2C1. The expression analysis showed that HC treatment upregulated the expression of PpPP2C1 and downregulated the expression of PpL-{"type":"entrez-nucleotide","attrs":{"text":"T31511","term_id":"613609"}}T31511 and Pp-miRn182. Moreover, HC treatment inhibited the accumulation of ABA signaling pathway-related genes and hydrogen peroxide (H₂O₂). Furthermore, overexpression of Pp-miRn182 reduced the inhibitory effect of PpPP2C1 on the H₂O₂ content. In summary, our study suggests that downregulation of PpL-{"type":"entrez-nucleotide","attrs":{"text":"T31511","term_id":"613609"}}T31511-derived Pp-miRn182 promotes HC-induced endodormancy release in pear plants through the PP2C-H₂O₂ pathway.     

High pressure enhances activity and selectivity of Candida rugosa lipase immobilized onto silica nanoparticles in organic solvent

High hydrostatic pressure has been increasingly utilized to improve functions of enzymes, and most of such studies are currently focused on free enzymes in aqueous solution or organic solvent. In this work, Candida rugosa lipase (CRL) was immobilized onto silica nanoparticles and its activity and enantioselectivity in organic solvent were evaluated at high pressures under different water activities. The application of high hydrostatic pressures (50–200 MPa) led to improved activities of immobilized CRL for transesterification of (R)-1-phenylpropan-2-ol with vinyl acetate by 4–6 folds. Additionally the immobilization of CRL resulted in a significant change of selectivities, shifting the enantiomeric excess from the (R)- towards (S)-1-phenylpropan-2-yl acetate product at atmospheric pressure. The application of high pressures led to either enantiomeric excess towards (R)-1-phenylpropan-2-yl or no enantiomeric selectivity, depending on the water activities in the organic solvent and the level of pressures. The interesting behaviour of immobilized CRL under high pressures offers new opportunities to modulate enzyme functions through combination of high pressures and enzyme immobilization.     

Engineering proteolytically-degradable artificial extracellular matrices

Hydrogels are widely used as provisional matrices for tissue engineering and regenerative medicine, showing also great promise as platforms for 3D cell culture. Different bio-functionalization strategies have been proposed to enhance the biological performance of hydrogels, particularly when they lack intrinsic bioactivity. In this context, the design of artificial materials that mimic structural and functional features of the natural extracellular matrix (ECM) has been pursued. This review presents an overview on bioengineering approaches of integrating protease-sensitive motifs into hydrogels, for the creation of cell-responsive biomimetic scaffolding materials that degrade in response to their proteolytic microenvironment. The successful incorporation of protease-sensitive motifs in several synthetic and natural polymers, which has been achieved using various chemical routes, is described. In each case, the selected peptide sequences and their target proteases are highlighted, along with the main achievements of the study. A critical analysis of current limitations and recent advances is also provided, along with suggestions for further improvements.