通过在温和的条件下通过铜催化的磷化磷与烯基硼酸的氧化偶联反应,开发了一种可调谐策略,以高至极好的收率制备α,β-不饱和酯和α,β-不饱和γ-酮酯。不加水的反应得到α,β-不饱和酯,酮和酰胺,而α,β-不饱和γ-酮酯,1,4-α,β-不饱和二酮和α,β-不饱和γ-酮酰胺是使用5.0当量时获得。水。高2 O 18标记实验表明,水在α,β-不饱和γ-酮酸酯的形成中起着重要作用。在机理研究的基础上,提出了α,β-不饱和酯和α,β-不饱和γ-酮酯的合理形成机理。salts盐也可以代替磷化磷化物直接用作偶联伴侣。该反应表现出广泛的底物范围,良好的官能团耐受性,良好的区域选择性和多种偶联产物。
In Situ Generation of Quinolinium Ylides from Diazo Compounds: Copper-Catalyzed Synthesis of Indolizine
作者:Rongxiang Chen、Yanwei Zhao、Hongmei Sun、Ying Shao、Yudong Xu、Meihua Ma、Liang Ma、Xiaobing Wan
DOI:10.1021/acs.joc.7b01042
日期:2017.9.15
The Cu-catalyzedthree-component reaction between quinolines, diazo compounds, and alkenes has been established for direct construction of indolizine derivatives via quinolinium ylides. This methodology is distinguished by the use of a commercially inexpensive catalyst and readily available starting materials, wide substrate scope, and operational simplicity.
Herein, an atom-economical and eco-friendly electrochemical oxidation/cyclization of glycinederivatives through intramolecular Shono-type oxidative coupling is disclosed, leading to a variety of 2-substituted benzoxazoles in 51–85% yields. This oxidative cyclization proceeded in transition metal- and oxidant-free conditions and generated H2 as only a byproduct. Additionally, gram-scale reactions and
在此,公开了一种通过分子内 Shono 型氧化偶联对甘氨酸衍生物进行原子经济且环保的电化学氧化/环化,从而以 51-85% 的收率生成多种 2-取代苯并恶唑。这种氧化环化在无过渡金属和无氧化剂的条件下进行,并产生 H 2作为副产物。此外,克级反应和广泛的底物范围证明了该协议的合成有用性。
Diazoacetates as Terminating Agents in Living Ring-Opening Metathesis Polymerization: Synthesis of Chain-End-Functionalized Polymers
作者:Xin Wang、Yichen Sun、Xing-Qi Yao、Yan Xu、Jianbo Wang
DOI:10.1021/acs.macromol.2c01402
日期:2022.10.11
We report herein a simple, efficient strategy to access diverse end-functionalized polymers from a livingring-openingmetathesis polymerization process using diazoacetates as a new terminating agent. Such a terminating process occurs via a C═C bond-forming reaction between the chain-end ruthenium carbenes and the diazoacetates, resulting in the rapid construction of a unique, α,β-unsaturated carbonyl
Metal-free, visible-light driven α-C(sp<sup>3</sup>)–H <i>gem</i>-difluoroallylation of glycine derivatives with trifluoromethyl alkenes and 1,3-enynes
A metal free, visible-light driven α-C(sp3)−H gem-difluoroallylation of glycine derivatives with CF3-alkenes and 1,3-enynes is presented under redox-neutral conditions with good yields and excellent functional group compatibility.