Cu / CuxOy NPs结构化的COF:一种可循环利用的催化剂,用于通过大气环化CO2的利用来合成恶唑烷二酮。
摘要:
本研究描述了具有优异的表面积,可调节的孔径和巨大的CO 2捕集效率的结晶共价有机骨架(COF)的有利构造,可通过将CO 2引入反应性极强的有机骨架中来促进新型多组分环化。在催化性Cu / Cu x O y NP负载的COF的存在下,几种2-溴-3-烷基丙烯酸与几种胺衍生物和CO 2(0.1 MPa)的结合以优异的收率转化为所需的恶唑烷二酮。 96%)在无碱条件和环境温度下进行。
Transition metal-free diastereospecific synthesis of (Z)-2-arylidene-2,3-dihydrobenzo[b][1,4]dioxines by reaction of (Z)-1,2-dibromo-3-aryl-2-propenes with catechols
作者:Szymon P. Rekowski、Aabid A. Wani、Jürgen Conrad、Prasad V. Bharatam、Wolfgang Frey、Uwe Beifuss
DOI:10.1016/j.tet.2020.131482
日期:2020.10
A transition metal-free, diastereospecific reaction between substituted (Z)-1,2-dibromo-3-phenyl-2-propenes and substitutedcatechols using Cs2CO3 as a base at 140 °C for 18 h delivers exclusively substituted (Z)-2-arylidene-2,3-dihydrobenzo[b][1,4]dioxines in yields up to 89%. Experiments as well as quantum chemical calculations support the assumption that the one pot transformation proceeds as an
在140°C下以Cs 2 CO 3为碱在取代的(Z)-1,2-二溴-3-苯基-2-丙烯与取代的邻苯二酚之间进行的无过渡金属非对映异构反应可产生仅被取代的(Z)-2-亚芳基-2,3-二氢苯并[ b ] [1,4]二恶英的产率高达89%。实验以及量子化学计算均支持以下假设:一锅转化以分子间O-烯丙基化/分子内O-乙烯基化的方式进行。
New Synthesis and Application of 3-Substituted Prolinols
Carbon skeleton of polysubstituted pyroglutamates with three contiguous asymmetric centers was built up in one base-induced coupling/cyclization reaction of α-sulfonylacetamide with 2-bromo-2-propenoates. A simple transformation to 3-substituted prolinols can be easily achieved via reduction and desulfonation. A ring expansion of prolinol has been used as the key step in the formal synthesis of isoguvacine and paroxetine. The one-pot conversion of 3-substituted prolinol to the 3-substituted pyroglutamic acid is also reported.
The reaction of substituted ethyl α-bromocinnamates with tetrabutyl ammonium fluoride
作者:Yan Liang、Ying Peng Zhang、Wei Yu
DOI:10.1016/j.cclet.2012.05.015
日期:2012.7
-bromocinnamates with tetrabutyl ammonium fluoride (TBAF) was influenced largely by the position of the substituent at the phenylring. While the substrates without an ortho substituent at the phenylring were transformed to the corresponding β -fluoro ethyl cinnamates under the reaction conditions, the presence of an ortho substituent only resulted in the formation of ethyl 3-phenylpropiolate derivatives
Chemical fixation of carbon dioxide by copper catalyzed multicomponent reactions for oxazolidinedione syntheses
作者:Siddharth Sharma、Ajay K. Singh、Devendra Singh、Dong-Pyo Kim
DOI:10.1039/c4gc02089h
日期:——
The quest to reduce greenhouse gases has triggered the development of new chemical fixation of carbon dioxide.
减少温室气体排放的探索已经引发了新的化学固定二氧化碳的发展。
A convenient method for the synthesis of (Z)-α-haloacrylates: Lewis base-catalyzed carbonyl olefination using α-halo-C,O-bis(trimethylsilyl)ketene acetals
synthesis of (Z)-α-haloacrylates from variousaldehydes that uses α-halogenated ethyl-C,O-bis(trimethylsilyl)keteneacetals in the presence of a Lewis base catalyst such as acetate salts was established. This procedure gives the corresponding α-halo-α,β-unsaturated esters in high yields with excellent stereoselectivity from E/Z mixtures of ketene silyl acetals under mild conditions.