The α‐arylation of enolizable aryl ketones can be carried out with aryl halides under transition‐metal‐free conditions using KOtBu in DMF. The α‐aryl ketones thus obtained can be used for step‐ and cost‐economic syntheses of fused heterocycles and Tamoxifen. Mechanistic studies demonstrate the synergetic role of base and solvent for the initiation of the radical process.
可以在DMF中使用KO t Bu在无过渡金属的条件下,用芳基卤化物进行可烯丙基芳基酮的α-芳基化反应。由此获得的α-芳基酮可用于稠合杂环和他莫昔芬的分步和成本经济合成。机理研究表明,碱和溶剂对自由基过程的启动具有协同作用。
Highly stereoselective nickel-catalyzed difluoroalkylation of aryl ketones to tetrasubstituted monofluoroalkenes and quaternary alkyl difluorides
作者:Chao Li、Yi-Xuan Cao、Ruo-Xing Jin、Kang-Jie Bian、Zi-Yang Qin、Quan Lan、Xi-Sheng Wang
DOI:10.1039/c9sc02806d
日期:——
stereo-defined tetrasubstituted monofluoroalkenes or quaternary alkyl difluorides from secondary or tertiary ketones, respectively, has been established. Mechanistic investigations indicated that these C-H fluoroalkylations proceed via a Ni(i)/Ni(iii) catalytic cycle. An obvious fluorine effect was observed in the reaction, and this reaction has demonstrated high stereoselectivity, mild conditions, and broad
Selective α-Methylation of Aryl Ketones Using Quaternary Ammonium Salts as Solid Methylating Agents
作者:Johanna Templ、Michael Schnürch
DOI:10.1021/acs.joc.1c03158
日期:2022.3.18
We describe the use of phenyl trimethylammonium iodide (PhMe3NI) as an alternative methylatingagent for introducing a CH3 group in α-position to a carbonyl group. Compared to conventional methylatingagents, quaternary ammonium salts have the advantages of being nonvolatile, noncancerogenic, and easy-to-handle solids. This regioselective method is characterized by ease of operational setup, use of
Exogenous Ligand-Free NiH-Catalyzed Hydroacylation of Aryl Alkenes with Aroyl Fluorides
作者:Jihye Kim、Jieun Jang、Yoonho Lee、Kwangmin Shin
DOI:10.1021/acs.orglett.2c02110
日期:2022.7.29
Acylfluorides have emerged as efficient acyl group donors, but these attractive reagents have rarely been utilized in transition-metal-catalyzed hydroacylation. Herein we report a nickel hydride-catalyzed hydroacylation of aryl alkenes using aroyl fluorides. The reaction proceeds without recourse to an exogenous ligand under mild conditions. The synthetic utility of the present method is demonstrated
Highly efficient α-arylation of aryl ketones with aryl chlorides by using bulky imidazolylidene-ligated oxazoline palladacycles
作者:Xian Wei、Kun Wang、Weiwei Fang
DOI:10.1039/d3ob00354j
日期:——
important building blocks. Herein, we presented an efficient catalytic system for the α-arylation of aryl ketones with inactive aryl chlorides by firstly using N,N′-bis(2,6-diisopropylphenyl)-imidazol-2-ylidene (IPr)-ligated chiral oxazoline palladacycles, and tolerated a wide range of substrates at lowcatalystloadings, leading to the desired products in good to excellent yields.
羰基化合物的 α-芳基衍生物是重要的组成部分。在此,我们首先使用N , N ′-双(2,6-二异丙基苯基)-咪唑-2-亚基 (IPr)-连接的手性恶唑啉钯环,提出了一种高效的芳基酮与非活性芳基氯的 α-芳基化催化体系, 并在低催化剂负载下耐受多种底物, 从而以良好的收率获得所需的产品。