已经成功开发了一种从吡啶盐直接获得 4-碘吡咯-2-甲醛的简便途径,该途径经历了级联吡咯-2-甲醛构建/选择性 C4 位碘化过程。使用 Na 2 S 2 O 8作为氧化剂和容易获得的碘化钠作为碘源,以良好到极好的收率获得了多种 4-iodopyrrole-2-carbaldehyde。原子经济和步骤经济、良好的官能团耐受性、高区域选择性以及温和的条件使这种转变成为丰富吡咯类库的替代策略。
Delineating the Role of Substituents on the Coordination Behavior of Aroylhydrazone Ligands in Pd
<sup>II</sup>
Complexes and their Influence on Suzuki–Miyaura Coupling in Aqueous Media
piperonal aroylhydrazone ligands (HL1–HL4) with [PdCl2(PPh3)2] in CH3OH and CHCl3 afforded four new Pd(II) complexes (1–4) featuring diverse coordination behaviors. These complexes 1–4 were fully characterized by elemental analyses, UV/Visible, FT‐IR and 1H/13C NMR spectra. The variant coordination modes of piperonal aroylhydrazone ligands with Pd(II) ion in these complexes were unambiguously confirmed
α-Halo carbonyls enable meta selective primary, secondary and tertiary C–H alkylations by ruthenium catalysis
作者:Andrew J. Paterson、Callum J. Heron、Claire L. McMullin、Mary F. Mahon、Neil J. Press、Christopher G. Frost
DOI:10.1039/c7ob01192j
日期:——
selective C–H alkylation of arenes is described using a wide range of α-halo carbonyls as coupling partners. Previously unreported primary alkylations with high meta selectivity have been enabled by this methodology whereas using straight chain alkyl halides affords ortho substituted products. Mechanistic analysis reveals an activation pathway whereby cyclometalation with a ruthenium(II) complex activates
catalytic reactions using transition metals is an important challenge in organic chemistry in which the intermediates are related to those produced in the classical cross-couplingreactions. As part of our research program devoted to the development of metal-catalyzed reactions using indium organometallics, a protocol for the C⁻H activation and C⁻C coupling of 2-arylpyridines with triorganoindium reagents
Palladium-Catalyzed Methylation of Aryl C−H Bond by Using Peroxides
作者:Yuhua Zhang、Jianqing Feng、Chao-Jun Li
DOI:10.1021/ja0775063
日期:2008.3.1
A novel Pd(OAc)2-catalyzed methylation reaction by dicumylperoxide via aryl C−H bond activation was discovered. Various 2-phenylpyridine and acetanilides can be used as reactants in these reactions. Peroxide was used as both the methylatingreagent and the hydrogenacceptor.
Cobalt-catalysed C–H methylation for late-stage drug diversification
作者:Stig D. Friis、Magnus J. Johansson、Lutz Ackermann
DOI:10.1038/s41557-020-0475-7
日期:2020.6
despite its significance, accessing such analogues via derivatization at a late stage remains a pivotal challenge. In an effort to mitigate this major limitation, we here present a strategy for the cobalt-catalysed late-stage C–H methylation of structurally complex drug molecules. Enabling broad applicability, the transformation relies on a boron-based methyl source and takes advantage of inherently present