has been developed toward a range of carbocycles. The key success is based on the use of a batch of newly designed cyclic carbonates as substrates that can provide carbon–carbon zwitterion intermediate under palladium catalysis. The kinetics of the reactions are controllable toward either strained seven- or thermodynamically more favored five-membered carbocycles. The release of this chemistry will
Tailoring a magnetically separable NiFe2O4 nanoparticle catalyst for Knoevenagel condensation
作者:Qichen Li、Xiaozhong Wang、Yanyun Yu、Yingqi Chen、Liyan Dai
DOI:10.1016/j.tet.2016.11.011
日期:2016.12
A magnetically separable NiFe2O4 nanoparticle catalyst was prepared readily via a simple one-step hydrothermal process. The catalytic performance of this hetero-nanostructure was investigated by Kneovenagel condensation with aldehydes and active methylene compounds under mild conditions. The newly designed catalyst exhibited a prominent catalytic activity with 99.5% conversion, 99% selectivity and
可通过简单的一步水热法容易地制备可磁分离的NiFe 2 O 4纳米颗粒催化剂。在温和条件下,通过Kneovenagel与醛和活性亚甲基化合物的缩合反应,研究了这种杂化纳米结构的催化性能。新设计的催化剂表现出突出的催化活性,转化率为99.5%,选择性为99%,产率极高,与各种醛和活性亚甲基化合物兼容,转化率也很高,选择性也很高。通过施加外部磁场,这种易于分离的混合材料(NiFe 2 O 4)可以循环使用八次而不会造成重大损失,从而开创了低成本制造C的新时代。C债券,用于大规模扩展用途,尤其是在制药和化妆品行业。
corresponding properties, and a new linkage is essential to the progress of this field. Herein, condensation of 1,3,5-triformylphloroglucinol with 1,1′-(1,4-phenylene)bis(thiourea), 1,1′-(2,5-dimethyl-1,4-phenylene)bis(thiourea) or 1,1′-(3,3′-dimethyl-[1,1′-biphenyl]-4,4′-diyl)bis(thiourea) were applied to construct COFs with thiourea linkages for the first time.
Piperidine-Mediated [3 + 3] Cyclization of 2-Amino-4<i>H</i>-chromen-4-ones and 2-Benzylidenemalononitriles: To Access 2-Aminochromeno[2,3-<i>b</i>]pyridine Derivatives
作者:Dan Zhang、Naili Luo、Jianbo Gan、Xinyi Wan、Cunde Wang
DOI:10.1021/acs.joc.1c00797
日期:2021.7.2
Piperidine-mediated [3 + 3] cyclization of 2-amino-4H-chromen-4-ones and substituted 2-benzylidenemalononitriles was developed for the synthesis of 2-amino-4-aryl-5H-chromeno[2,3-b]pyridin-5-one derivatives. This novel transformation provides a highly efficient and facile route to functionalized 5H-chromeno[2,3-b]pyridines from readily available substrates under mild reaction conditions.
哌啶介导的 [3 + 3] 环化 2-amino-4 H -chromen-4-ones 和取代的 2-benzylidenemalononitriles 被开发用于合成 2-amino-4-aryl-5 H - chromeno[2,3- b ]pyridin-5-one 衍生物。这种新的转化为在温和反应条件下从容易获得的底物制备官能化的 5 H -色基[2,3- b ]吡啶提供了一种高效且简便的途径。
Na2CO3-Mediated [3+3] Annulation Reaction of Substituted Benzamidines with 2-Benzylidenemalononitriles: Access to Substituted Pyrimidine-4,6-diamines
An efficient protocol for the synthesis of 2-aryl-5-benzylpyrimidine-4,6-diamines from readily available substituted 2-benzylidenemalononitriles and substituted benzamidines was developed. This practical protocol provides high value pyrimidine-4,6-diamines in moderate to good yields under simple reaction conditions. This approach also enables some modifications of structurally complex bioactive molecules