共查询到20条相似文献,搜索用时 109 毫秒
1.
2.
3.
研究了苄基卤代物与三丁基烯丙基锡的偶联反应,当以10mol%Cu(OTf)2为催化剂,CH2Cl2为溶剂时,1-氯甲基-4-苯基萘与三丁基烯丙基锡于室温反应1h,交叉偶联反应产物1-(3-丁烯基)-4-苯基萘(3b)收率即达93%.结果表明,芳环含供电子基的底物反应活性较高,在室温反应几分钟即可完成,而芳环含吸电子基的底物反应活性低.反应产物3b,1-溴-4-(3-丁烯基)萘(3c)和1-(3-丁烯基)-4-硝基萘(3f)未见报道,且其结构经表征确认. 相似文献
4.
5.
6.
7.
8.
CO2甲烷化反应是一个复杂的多相催化过程,在反应过程中会产生各种各样的中间体,其反应路径目前还存在许多争议和矛盾。深入系统地研究CO2甲烷化反应中催化剂表面中间体的演变过程,可以进一步从机理的角度优化催化剂的设计方案,提高催化性能。本工作主要基于原位红外光谱表征技术,总结梳理了最近关于CO2甲烷化反应路径研究的相关工作,着重探讨了负载型催化剂的活性金属、载体、助剂、合成方法等因素对CO2甲烷化反应路径的影响以及由此对催化剂性能所产生的积极效果。同时针对现阶段所面临的争论点,即反应气CO2与H2的活化位点、催化剂的活性位点以及未来可行的研究方法进行了详细论述。 相似文献
9.
C60与胺类化合物的反应是C60衍生化的重要方法。 本文介绍了C60氢胺化反应的一般规律和特点,对C60氢胺化反应在制备含C60高分子功能材料、含C60自组装单分子膜(SAM)、含C60有机/无机纳米材料和C60生物功能材料等方面应用的研究进展作了综述。 相似文献
10.
本文采用计算流体力学方法建立了以沼气为原料气的CO2甲烷化反应器模型,通过多物理场耦合求解获得了不同反应条件下甲烷化反应器内的温度分布和反应速率等数据,考察了反应温度、压力、流速等对甲烷化反应的影响。研究结果表明,提高反应温度和压力有利于提高CO2甲烷化反应速率和生产效率,但在相同装填量的催化剂床层CO2的出口转化率降低。以Al2O3为载体的Ni催化剂,在床层直径小于25 mm时,恒壁温条件下床层内外温差为3.1℃。综合热力学和动力学两方面的影响,以沼气为原料的CO2甲烷化反应温度应以300~400℃为宜。在300℃,1.0 MPa的反应条件下,反应停留时间大于257.6 s可达到高于98%的CO2转化率。 相似文献
11.
Copper was found to be able to promote the SnC12-mediated carbonyl allylation reactions in water, giving the corresponding homoallylic alcohol products in very high yields. Detailed studies showed that the reaction could be applied to a variety of carbonyl compounds including those with hydroxyl, amino and nitro groups. It was also found that this reaction showed good regioselectivities for some substrates. Furthermore, carefully controled experiments and in situ NMR measurements provided important insights into the mechanism of the newly developed reaction. 相似文献
12.
13.
氮气保护条件下,纳米铝在0.1 N NH4Cl溶液中,能有效地促进羰基化合物与烯丙基溴进行Barbier-Grignard型烯丙基化反应,得到相应高烯丙醇。芳香族醛或酮的烯丙基化产率较高,而脂肪族羰基化合物反应产率低,反应产率受羰基空间位阻影响大,在同样条件下,邻羟基羰基化合物烯丙基化产物主要是赤式-邻二醇。 相似文献
14.
A novel mediator (Al/KF) has been developed and employed in the Barbier‐type alkylations of various aldehydes and ketones with alkyl halide in water. The carbonyl compounds could be effectively converted into corresponding homoallylic alcohol in good yields only when allyl bromides or substituted allyl bromides were used as halides. Aromatic aldehydes could afford homoallylic alcohols in high yields, unfortunately, the allylation of aromatic aldehyde substituted by nitro‐ or amino‐group could not proceed smoothly, and the allylation yields of ketones and aliphatic carbonyl compounds were lower under the same condition. The diastereoselectivity and regioseletivity of the reaction have also been studied, the predominant products preferred the erythro‐ or anti‐isomer in dominant γ‐adduct by using Al/KF mediated allylation of benzaldehydes with cinnamyl bromide and ethyl 4‐bromo‐2‐butenoate in water. 相似文献
15.
Catalyzed by AgNO3, Mg was found for the first time to be able to mediate the coupling reaction between aromatic aldehydes and benzyl bromide or chloride in water. The yields were slightly higher than the recent results for Mg-mediated allylation despite the fact that aqueous benzylation is intrinsically much harder than allylation. It was also found that the coupling reaction was chemoselective for aromatic aldehydes over aliphatic aldehydes, and chemoselective for aromatic aldehydes over aromatic ketones. 相似文献
16.
Barbier allylation and Friedel-Crafts alkylation of (un)substituted benzaldehydes, allylbromide and phenols can be combined in a one-pot process in ionic liquid (BuPyC1/SnC12·2H2O) to directly synthesize 4-(2-hydroxyphenyl)- 4-[(un)substituted phenyl]but-1-ene compounds, which were applied to the synthesis of 4-(substituted phenyl)- chromans through intramolecular cyclization reactions. 相似文献
17.
In/SBA-15催化剂的一步法制备及其在水介质中Barbier反应中的应用 总被引:1,自引:0,他引:1
采用金属In的石蜡溶液浸渍载体, 一步法制备具有介孔结构的In/SBA-15催化剂. 在水介质中苯甲醛与烯丙基溴的Barbier反应中, 发现负载量为w(In)=13%的In/SBA-15的催化活性显著高于金属In颗粒催化剂, 而选择性相似, 目标产物1-苯基-3-丁烯基-1-醇的得率可达89.2%. In/SBA-15的高活性主要归因于In活性位在SBA-15上的高分散, 以及规整的介孔结构有利于反应物分子的扩散. 同时, 金属In与SBA-15间较强的相互作用也可稳定In活性位, 显示出良好的应用潜力. 相似文献
18.
A simple and effective pinacol coupling of various aromatic aldehydes mediated by gallium in good yields has been carried out. The reaction is highly effective in water in the prurience of KOH or HCl and was strongly affected by the steric environ-ment surrounding the carbonyl group. Aliphaflc aldehydes, ke-tones and aromatic ketones appear inert under the same reac-tion conditions. 相似文献
19.
20.
Overthepasttenyears ,thepursuitofsynthetictar getswithincreasingcomplexityhasresultedinthedevel opmentofreactionsthatemphasizechemo ,regio ,di astereo andenantioselectivity .1 4 Theadditionsoforganichalidetocarbonylcompounds ,promotedbyvariousmet alsandacidc… 相似文献