Platinum Oxide Catalyzed Hydrosilylation of Unsymmetrical Internal Aryl Alkynes under Ortho-Substituent Regiocontrol
摘要:
[GRAPHICS]PtO2- and H2PtCl6-catalyzed hydrosilylation of internal aryl alkynes having a para or an ortho substituent with triethylsilane are discussed and compared. The regioselectivity of the H-Si bond addition was found to be controlled by the ortho substituent rather than the nature of the platinum catalyst. Arylallcynes with an ortho substituent, regardless of its electronic nature, directed the silyl substituent mainly to the a-position. PtO2 proved to be a versatile and powerful catalyst compared to H2PtCl6 since it prevents the alkyne reduction.
A highly efficient palladium-catalyzed cascade annulation of pyrazolones and aryl iodides to access various benzo[c]cinnoline derivatives has been achieved at 80 °C. A pyridine-type ligand could improve the reaction efficiency under current reaction conditions, giving a higher product yield up to 94%. This novel approach provided a one-pot dual C–H activation strategy with good functional group tolerance
在80°C时,已经实现了高效的钯催化吡唑啉酮和芳基碘的级联环化反应,以得到各种苯并[ c ]肉桂酸衍生物。吡啶类配体可提高当前反应条件下的反应效率,最高收率可达94%。这种新颖的方法提供了具有良好官能团耐受性的一锅双C–H活化策略,例如卤素,甲氧基,硝基,酯,苯酚等。该产物可以很容易地转化为cinnoline衍生物。
作者:María Jesús Cabrera-Afonso、Zhi-Peng Lu、Christopher B. Kelly、Simon B. Lang、Ryan Dykstra、Osvaldo Gutierrez、Gary A. Molander
DOI:10.1039/c7sc05402e
日期:——
employed to prepare sulfones with biological relevance (e.g., in bioconjugation, drug substance synthesis, etc.) as demonstrated in the synthesis of drug-like compounds or their precursors. When paired with existing Ni/photoredox chemistry for Csp3–Csp2 cross-coupling, an array of diverse sulfone scaffolds can be readily assembled from bifunctional electrophiles. A mechanistic manifold consistent with
该报告详细介绍了通过镍/光氧化还原双重催化构建芳基和杂芳基砜的策略的开发和实施。使用芳基亚磺酸盐,可以在室温、无碱条件下形成C-S键。一系列芳基卤化物和杂芳基卤化物与该方法兼容。所描述的反应的广泛耐受性和温和性质可以潜在地用于制备具有生物相关性的砜(例如,在生物共轭、药物物质合成等中),如在药物样化合物或其前体的合成中所证明的。当与现有的用于 C sp 3 –C sp 2交叉偶联的 Ni/光氧化还原化学配对时,可以很容易地从双功能亲电子试剂组装一系列不同的砜支架。提出了与实验和计算数据一致的机械流形。
Sonogashira coupling reactions in biodegradable ionic liquids derived from nicotinic acid
作者:Jitendra R. Harjani、Theodore J. Abraham、Alwyn T. Gomez、M. Teresa Garcia、Robert D. Singer、Peter J. Scammells
DOI:10.1039/b919394d
日期:——
The biodegradable ionic liquids, 3-butoxycarbonyl-1-methylpyridinium bis(trifluoromethanesulfonyl)imides (1a–d), have been evaluated as solvents for copper- and phosphine-free Sonogashiracoupling reactions. The stability of these ionic liquids toward basic conditions was analysed in order to further probe their utility for transition metal catalyzed reactions which require the presence of a base.
Palladium-Catalyzed Carbonylative Coupling of Tributyl(1-fluorovinyl)stannane with Aryl Halides and Aryl Triflates
作者:Takeshi Hanamoto、Kumiko Handa、Tomonori Mido
DOI:10.1246/bcsj.75.2497
日期:2002.11
catalytic amount of CsF in DMF in good yields. The palladium-catalyzedcarbonylative cross-coupling reaction of 2 with aryl iodides bearing various functional groups smoothly proceeded giving the corresponding aryl 1-fluorovinyl ketones in good yields under an atmospheric pressure of carbon monoxide. A similar carbonylative cross-coupling reaction of 2 with aryl triflates was also accomplished in the presence
Cross-Coupling Reactions of (1-Fluorovinyl)methydiphenylsilane<sup>1</sup> with Aryl Halides and Aryl Triflates
作者:Takeshi Hanamoto、Tomoko Kobayashi
DOI:10.1021/jo030111r
日期:2003.8.1
of functional groups (nitro, ester, ketone, and ether) on the aromatic rings can be tolerated under these mild conditions. Aryl iodides are superior to aryl bromides as the coupling reaction partner. The cross-couplingreaction of 1 with aryltriflates instead of aryl halides was also accomplished in the presence of tetrabutylammonium iodide (n-Bu(4)NI) as the additive under similar conditions.