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。
Synthesis of 2-Substituted Benzofurans and Indoles Using Functionalized Titanium Benzylidene Reagents on Solid Phase
作者:Calum Macleod、Gordon J. McKiernan、Emma J. Guthrie、Louis J. Farrugia、Dieter W. Hamprecht、Jackie Macritchie、Richard C. Hartley
DOI:10.1021/jo026384o
日期:2003.1.1
nitrogen nucleophile in the ortho position were generated from thioacetals, using low-valent titanocene complex, Cp2Ti[P(OEt)3]2. Methylene acetal, alkyl ether, silyl ether, fluoro, tertiary amino, and N-alkyl, N-benzyl, N-prenyl, and N-silyl tert-butyl carbamate groups were tolerated in the titanium alkylidene reagents (Schrock carbenes). Aryl-chlorine bonds were stable to the titanium benzylidene functionality
One-Pot Synthesis of Substituted Benzo[<i>b</i>]furans from Mono- and Dichlorophenols Using Palladium Catalysts Bearing Dihydroxyterphenylphosphine
作者:Miyuki Yamaguchi、Haruka Katsumata、Kei Manabe
DOI:10.1021/jo401503t
日期:2013.9.20
on the phosphorus atom (Cy-DHTP) was found to be a powerful ligand for the palladium-catalyzed one-potsynthesis of substituted benzo[b]furans from 2-chlorophenols and terminal alkynes. This catalyst system was also applicable to the sequential one-potsynthesis of disubstituted benzo[b]furans from dichlorophenols via the Suzuki–Miyaura cross-coupling of chlorobenzo[b]furan with boronic acids. The use
发现在磷原子上带有环己基的二羟基叔苯基膦(Cy-DHTP)是钯催化由一锅法从2-氯酚和末端炔烃合成取代苯并[ b ]呋喃的强配体。该催化剂体系还适用于通过氯苯并[ b ]呋喃与硼酸的Suzuki-Miyaura交叉偶联从二氯苯酚一步法一锅合成二取代的苯并[ b ]呋喃。Cy-DHTP和XPhos这两种配体的使用是促进反应的关键。机理研究表明,Pd–Cy-DHTP催化剂是Sonogashira交叉偶联步骤中的活性物种,而Pd–XPhos催化剂则加速了Suzuki–Miyaura交叉偶联步骤。
One-pot synthesis of 2,3-disubstituted benzofurans from 2-chlorophenols using palladium–dihydroxyterphenylphosphine catalyst
2,3-Disubstituted benzofurans possessing 2-hydroxyphenyl moiety at the C-3 position were synthesized from readily available 2-chlorophenols and terminal alkynes by hydroxy-directed ortho-Sonogashira coupling and subsequent oxypalladation/reductive elimination, using Pd-dihydroxyterphenylphosphine catalyst. The catalyst accelerates not only the Sonogashira coupling but also the introduction of 2-hydroxyphenyl
Nickel-Catalyzed Regioselectivity-Switchable Hydroheteroarylation of Vinylarenes with Electron-Rich Heteroarenes
作者:Yu Shui、Sajid Imran、Wen-Hui Jin、Yang Liu、Nadia Ismaeel、Hong-Mei Sun
DOI:10.1021/acs.orglett.3c03618
日期:2023.12.15
We report the first example of a regioselectivity switch in the hydroheteroarylation of vinylarenes with electron-rich heteroarenes, including benzofurans, benzothiophenes, and indoles, using an expedient ligand-controlled strategy. In the presence of NaOtBu, Ni(IMesMe)[P(OEt)3]Br2 yields C2-alkylated heteroarenes with high branched selectivity, whereas the use of Ni(IPr*OMe)[P(OEt)3]Br2 favors the
我们报告了使用便利的配体控制策略,在乙烯基芳烃与富电子杂芳烃(包括苯并呋喃、苯并噻吩和吲哚)的氢杂芳基化中进行区域选择性转换的第一个例子。在 NaO t Bu 存在下,Ni(IMes Me )[P(OEt) 3 ]Br 2产生具有高支化选择性的 C2-烷基化杂芳烃,而使用 Ni(IPr *OMe )[P(OEt) 3 ]Br 2有利于相应线性产物的形成。这种稳健的方法还可以在不使用导向基团的情况下轻松获得一系列 C2 烷基化的富电子杂芳烃。