A novel application of DDQ as electrophile in the Nenitzescu reaction
作者:U. Kucklaender、R. Bollig、W. Frank、A. Gratz、J. Jose
DOI:10.1016/j.bmc.2011.03.006
日期:2011.4
Reaction of 2,3-dichloro-5,6-dicyano-benzoquinone (DDQ) with secondary enaminones yields surprisingly 2-aza-spiro[4,5]decatrienes. The reaction occurs via cyclisation of the primary Michael-adduct with the nitrile group. Reaction of DDQ with tertiary and also certain secondary enamines leads to 3-amino-benzo[b]furan derivatives. This is formed not by Michael-addition, but via geminate radical ion pair
2,3-二氯-5,6-二氰基苯并醌(DDQ)与仲烯胺酮的反应令人惊讶地产生了2-氮杂-螺[4,5]癸二烯。该反应通过伯烷基加成基与腈基的环化而发生。DDQ与叔胺以及某些仲烯胺的反应生成3-氨基-苯并[ b ]呋喃衍生物。这不是通过迈克尔加成反应形成的,而是通过形成自由基自由基对并随后生成氧碳键生成苯并呋喃而形成的。对新产品进行了研究,以抑制纯化的人蛋白激酶CK2及其一般的细胞抑制活性。结果表明,活性最高的化合物是3-氨基-5-羟基-苯并呋喃衍生物11s,CK2的IC 50值为0.2μM。
Solvent-free iodine-promoted synthesis of 3,2′-pyrrolinyl spirooxindoles from alkylidene oxindoles and enamino esters under ball-milling conditions
作者:Hui Xu、Hong-Wei Liu、Hao-Sheng Lin、Guan-Wu Wang
DOI:10.1039/c7cc08306h
日期:——
A solvent-free mechanochemical reaction of alkylidene oxindoles with enamino esters via an iodine-promoted tandem Michael/cyclization sequence has been developed to provide a variety of spirocyclic oxindoles in moderate to good yields with excellent diastereoselectivities.
Fabrication of Ag/γ-Fe<sub>2</sub>O<sub>3</sub>@TiO<sub>2</sub> hollow magnetic core–shell nanospheres as highly efficient catalysts for the synthesis of β-enaminones
作者:Hongfei Huo、Xinzhe Li、Xingchun Zhou、Lixin Jiao、Shiling Zhao、Le Zhang、Wenzhu Li、Shuwen Li、Rong Li
DOI:10.1039/c5ra14878b
日期:——
Herein, we describe a method to prepare hollow magnetic mesoporous sphere catalysts (Ag/γ-Fe2O3@meso-TiO2).
Nucleophilicaddition of β-amino α,β-unsaturated ketones and esters to the S-Sdimer of 2- aminobenzenethiol which acts as an electrophile, followed by cyclization, lead to 4H-1,4- benzothiazine derivatives.
A novel and efficient I2/FeCl3-catalyzed dominoreaction of aurones with enamino esters via Michael addition, iodination, intramolecular nucleophilicsubstitution, and spiro ring opening processes has been developed, affording a vast variety of polysubstituted pyrroles in moderate to excellent yields. This protocol features mild reaction conditions, broad substrate scope, high atom economy and efficiency
已开发出一种新颖且高效的 I 2 /FeCl 3催化的金酮与烯胺酯的多米诺反应,通过迈克尔加成、碘化、分子内亲核取代和螺环开环过程,以中等至优异的收率提供多种多取代吡咯。该方案具有反应条件温和、底物范围广、原子经济性和效率高以及大规模合成的可行性等特点。提出了一种可能的吡咯合成机理。