Copper catalyzed direct alkenylation of simple alkanes with styrenes
作者:Yefeng Zhu、Yunyang Wei
DOI:10.1039/c4sc00093e
日期:——
A novel Cu-catalyzed direct alkenylation of simple alkanes with styrenes was described. In the presence of a catalytic amount of Cu(OTf)2, a diverse range of alkenes undergo coupling with cycloalkanes to produce (E)-alkyl alkenes. This transformation is proposed to proceed via a radical process.
Impregnated copper or palladium–copper on magnetite as catalysts for the domino and stepwise Sonogashira-cyclization processes: a straightforward synthesis of benzo[b]furans and indoles
作者:Rafael Cano、Miguel Yus、Diego J. Ramón
DOI:10.1016/j.tet.2011.12.042
日期:2012.2
An impregnated copper on magnetite catalyst is a versatile system for different domino Sonogashira-cyclization processes between 2-iodophenol and different alkynes to give the corresponding substituted benzo[b]furans. The catalyst could be recovered ten times without losing its activity. The related process using 2-iodoaniline was, however, better catalyzed by mixed palladium–copper on magnetite giving
Cobalt-Catalyzed Negishi Cross-Coupling Reactions of (Hetero)Arylzinc Reagents with Primary and Secondary Alkyl Bromides and Iodides
作者:Jeffrey M. Hammann、Diana Haas、Paul Knochel
DOI:10.1002/anie.201411960
日期:2015.4.7
di(hetero)arylzinc reagents with primary and secondaryalkyliodides or bromides using THF‐soluble CoCl2⋅2 LiCl and TMEDA as a ligand, which leads to the corresponding alkylated products in up to 88 % yield. A range of functional groups (e.g. COOR, CN, CF3, F) are tolerated in these substitution reactions. Remarkably, we do not observe rearrangement of secondaryalkyliodides to unbranched products. Additionally
Palladium complexes with an annellated mesoionic carbene (MIC) ligand: catalytic sequential Sonogashira coupling/cyclization reaction for one-pot synthesis of benzofuran, indole, isocoumarin and isoquinolone derivatives
作者:Akshi Tyagi、Noor U Din Reshi、Prosenjit Daw、Jitendra K. Bera
DOI:10.1039/d0dt02918a
日期:——
Two Pd(II) complexes (1 and 2) featuring a fused π-conjugated imidazo[1,2-a][1,8]naphthyridine-based mesoionic carbene ligand have been synthesized and structurally characterized. Both complexes effectively catalyze the one-pot synthesis of benzofuran starting from phenylacetylene and 2-iodophenol under mild conditions. Complex 1 is found to be an excellent catalyst for the straightforward access to
合成了两个Pd(II)配合物(1和2),这些配合物具有基于π-共轭咪唑并[1,2- a ] [1,8]萘啶基的介电卡宾配体的稠合结构。两种络合物在温和条件下均能有效地催化苯乙炔和2-碘苯酚的一锅法合成苯并呋喃。通过末端炔烃与苯酚,N-甲基苯胺,苯甲酸和N的2-碘衍生物的反应,发现配合物1是直接访问苯并呋喃,吲哚,异香豆素和异喹诺酮衍生物库的极佳催化剂。-甲基苯甲酰胺。使用多种不同取代的末端炔烃证明了催化方法的通用性,并以良好或优异的收率获得了相应的所需产物。在对照实验的基础上,提出了一种二循环机理,该机理涉及2-碘衍生物与炔烃的Sonogashira偶联以及随后的相应2-炔基化合物的环化。
Controlled Synthesis of 2- and 3-Substituted Benzo[<i>b</i>]furans
作者:Tao Pei、Cheng-yi Chen、Lisa DiMichele、Ian W. Davies
DOI:10.1021/ol102123u
日期:2010.11.5
A controlled regioselective synthesis of either C-2 or C-3 substituted benzo[b]furans from readily accessible 1-(2-hydroxyphenyl)-2-chloroethanones is described. Addition of a range of Grignard reagents to the α-chloro ketones generates alkoxide intermediates, which can form either 2-substituted benzo[b]furans via a [1,2]-arylmigration or 3-substituted benzo[b]furans via a direct cyclization and dehydration
描述了从容易获得的1-(2-羟苯基)-2-氯乙酮的C-2或C-3取代的苯并[ b ]呋喃的受控区域选择性合成。在α-氯代酮中添加一系列格氏试剂可生成醇盐中间体,该中间体可通过[1,2]-芳基迁移形成2-取代的苯并[ b ]呋喃,或通过a形成3-取代的苯并[ b ]呋喃。直接环化和脱水序列。提出了一种温度依赖性的[1,2]-芳基迁移机制,用于形成2-取代的苯并[ b ]呋喃。