在这项工作中,我们开发了一种新的方法,以单分散混合的Ag @的TiO 2层使用在所述Si钛促进的交联的纳米复合材料减少 H官能材料,聚甲基(PMHS)基半互穿网络(PMHSIPN)。将二氧化钛设计为高度分散在功能材料上,然后在温和条件下以均匀的尺寸和形状形成Ag @ TiO 2纳米颗粒。实验结果表明,纳米银催化剂(在PMHSIPN上制备的Ag @ TiO 2,即nanoAg @ TiO 2@PMHSIPN)在三氟甲基酮或α,β-不饱和三氟甲基酮与末端炔烃的炔基化反应中具有增强的催化活性。在该反应中,杂化的Ag @ TiO 2纳米颗粒对各种三氟甲基酮和α,β-不饱和三氟甲基酮选择性地1,2-炔基化成水中多种氟化醇具有很高的催化活性。最后,在nanoAg @ TiO 2的基础上@PMHSIPN催化的三氟甲基酮的炔基化反应,我们开发了一个新概念,即高反应性底物充当“反应性牵引剂”或“反应性跳板
Selective Insertion of Alkynes into C–C σ Bonds of Indolin-2-ones: Transition-Metal-Free Ring Expansion Reactions to Seven-Membered-Ring Benzolactams or Chromone Derivatives
作者:Mengdan Wang、Yajie Yang、Bo Song、Liqiang Yin、Shuhui Yan、Yanzhong Li
DOI:10.1021/acs.orglett.9b04081
日期:2020.1.3
An unprecedented ring expansion reaction of indolin-2-ones with alkynyl ketones under transition-metal-free conditions has been developed. Base-promoted selective cleavage of a C-Cσbond of the amide is the key in this process, which provides a straightforward and efficient way to synthesize seven-membered-ring benzolactams or chromone derivatives. The significant advantages of this method include
Base-Promoted Tandem Reaction towards Conjugated Dienone or Chromone Derivatives with a Cyano Group: Insertion of Alkynes into C-C σ-Bonds of 3-Oxopropanenitriles
作者:Qiyi Yao、Lingkai Kong、Fangfang Zhang、Xianghua Tao、Yanzhong Li
DOI:10.1002/adsc.201700565
日期:2017.9.18
alkynes into the C–C σ-bonds of α-cyano ketones were established to construct highlyfunctionalizedconjugated olefins or chromone derivativesvia transition metal-free tandem reactions. These reactions are initialized through the nucleophilic attack of α-cyano ketones to alkynones followed by intramolecular nucleophilic addition/ring-opening to furnish the cyano-containing alkenes. In the cases of alkynones
Base-mediated insertion reaction of alkynes into carbon–carbon σ-bonds of ethanones: synthesis of hydroxydienone and chromone derivatives
作者:Fangfang Zhang、Qiyi Yao、Yang Yuan、Murong Xu、Lingkai Kong、Yanzhong Li
DOI:10.1039/c7ob00476a
日期:——
Transition-metal free insertions of alkynes into carbon–carbon σ-bonds of ethanones have been reported. These tandem reactions offer an efficient synthesis of hydroxydienones and multi-substituted chromones. This is the first example of base-promoted insertion reactions of isolated carbon–carbon triple bonds into carbon–carbon σ-bonds with active methylene compounds bearing only one electron-withdrawing