卤素键催化作为一种激活有机分子的有力工具,最近受到越来越多的关注。然而,到目前为止,催化剂结构的变化非常有限。本文中,我们报道了使用碘炔作为卤素键供体催化剂的第一个例子。通过使用带有五氟苯基的碘炔作为催化剂,硫酰胺可以有效地活化并与2-氨基苯酚反应生成苯并恶唑,收率很高。包括13 C NMR光谱分析和一些对照实验在内的机理研究提供了具体的证据,表明这种催化活化是基于卤素键。因此,在这项研究中获得的结果表明,碘炔可以作为卤素支架催化未来发展的新支架。
A new synthetic method is reported in which 2-arylbenz(ox,imid,thi)azoles can be prepared by the palladium catalyzed condensation of aromatic halides with o-amino(phenol, aniline, thiophenol)s followed by dehydrative cyclization. This method is tolerant of a wide variety of functional groups on either aromatic ring and gives good to excellent yields of products.
A General, Multimetallic Cross-Ullmann Biheteroaryl Synthesis from Heteroaryl Halides and Heteroaryl Triflates
作者:Kai Kang、Nathan L. Loud、Tarah A. DiBenedetto、Daniel J. Weix
DOI:10.1021/jacs.1c10907
日期:2021.12.29
medicine and materials science, the synthesis of biheteroaryls by cross-coupling remains challenging. We describe here a new, general approach to biheteroaryls: the Ni- and Pd-catalyzed multimetallic cross-Ullmann coupling of heteroaryl halides with triflates. An array of 5-membered, 6-membered, and fused heteroaryl bromides and chlorides, as well as aryltriflates derived from heterocyclic phenols,
Efficient and versatile catalysis of N-alkylation of heterocyclic amines with alcohols and one-pot synthesis of 2-aryl substituted benzazoles with newly designed ruthenium(<scp>ii</scp>) complexes of PNS thiosemicarbazones
作者:Rangasamy Ramachandran、Govindan Prakash、Sellappan Selvamurugan、Periasamy Viswanathamurthi、Jan Grzegorz Malecki、Venkatachalam Ramkumar
DOI:10.1039/c4dt00006d
日期:——
or As, L = 2-(2-(diphenylphosphino)benzylidene) thiosemicarbazone (PNS-H), 2-(2-(diphenylphosphino)benzylidene)-N-methylthiosemicarbazone (PNS-Me), 2-(2-(diphenylphosphino)benzylidene)-N-phenylthiosemicarbazone (PNS-Ph)) have been synthesized and characterized by elemental analysis and spectroscopy (IR, UV-Vis, 1H, 13C, 31P-NMR) as well as ESI mass spectrometry. The molecular structures of complexes
Two New Mononuclear Copper(II)-Dipeptide Complexes of 2-(2′-Pyridyl)Benzoxazole: DNA Interaction, Antioxidation and in Vitro Cytotoxicity Studies
作者:Qian Gan、Yongyu Qi、Yahong Xiong、Yinlian Fu、Xueyi Le
DOI:10.1007/s10895-016-1999-5
日期:2017.3
reactions between the Cu(II) complexes with DNA are spontaneous with negative Gibbs free energy (ΔG). The positive changes of enthalpy (ΔH) and entropy (ΔS) suggested that the binding processes are dominated by hydrophobic interaction accompanying with endothermic. Also, the complexes exhibited efficient oxidative cleavage of pBR322 plasmid DNA in the presence of ascorbic acid, probably induced by •OH
两种新的单核混合配体铜(II)配合物[Cu(PBO)(Gly-gly)(H 2 O)]·ClO 4 ·1.5H 2 O(1)和[Cu(PBO)(Gly- L -leu) (H 2 O)]·ClO 4(2)(PBO是2-(2'-吡啶基)苯并恶唑,Gly-gly和Gly- L -leu是糖基-甘氨酸阴离子和糖基-L-亮氨酸阴离子),已经通过各种分析和光谱技术进行了制备和表征。使用多光谱方法(吸收,发射,圆二色性),粘度测定和电化学滴定以及分子对接技术研究了配合物与DNA的相互作用。结果表明,1和2通过插入模式与小牛胸腺DNA(CT-DNA)结合。热力学分析表明,Cu(II)配合物与DNA之间的反应是自发的,负Gibbs自由能(ΔG)。焓(ΔH)和熵(ΔS)的正变化)表明结合过程主要由疏水性相互作用和吸热引起。同样,在抗坏血酸的存在下,复合物表现出对pBR322质粒DNA的有效氧化裂解,这可能是
Cu(I) complexes regulated by N-heterocyclic ligands: Syntheses, structures, fluorescence and electrochemical properties
investigation shows that complexes 1–3 exhibit distinct tunable light green (512 nm)-to-yellow (557 nm) photoluminescence by varying the N-heterocyclic ligands. Three complexes show intense 2-PBO-based yellow, 3-PBO-based light green and intense PBM-based bright green luminescence upon irradiation with a standard UV lamp (λex = 254 nm) at room temperature. Moreover, the electrochemical properties of 1–3 have been