Functionalization of Azacalixaromatics by Cu(II)-Catalyzed Oxidative Cross-Coupling Reaction between the Arene C–H Bond and Boronic Acids
作者:Yang Liu、Chao Long、Liang Zhao、Mei-Xiang Wang
DOI:10.1021/acs.orglett.6b02530
日期:2016.10.7
Catalyzed by Cu(ClO4)2·6H2O under mild aerobic conditions using air as the oxidant, azacalix[1]arene[3]pyridines underwent a highly efficient oxidative cross-coupling reaction with a large number of aryl-, alkenyl-, and alkylboronic acids to afford diverse functionalized macrocycles. Stoichiometric reactions of an arylboronic acid with isolated and structurally well-defined high valent organocopper
Mechanistic Study on Cu(II)-Catalyzed Oxidative Cross-Coupling Reaction between Arenes and Boronic Acids under Aerobic Conditions
作者:Qian Zhang、Yang Liu、Ting Wang、Xinhao Zhang、Chao Long、Yun-Dong Wu、Mei-Xiang Wang
DOI:10.1021/jacs.8b01896
日期:2018.4.25
by Cu(II), transmetalation of arylboronate to ArCu(II), the redox reaction between the resulting ArCu(II)Ar' and ArCu(II) to form respectively ArCu(III)Ar' and ArCu(I), and finally reductive elimination of ArCu(III)Ar'. Under aerobic catalytic conditions, all Cu(I) ions released from reductive elimination of ArCu(III)Ar' and from protolysis of ArCu(I) were oxidized by oxygen to regenerate Cu(II) species
近年来,现代有机铜化学受到了极大的关注,因为与贵金属相比,铜盐天然丰富、价格低廉且毒性较小。铜盐还表现出催化和介导碳-碳和碳-杂原子键形成反应的多功能性。尽管铜盐在催化中有着广泛的应用,但反应机制仍然难以捉摸。使用氮杂杯[1]芳烃[3]吡啶,一种嵌入芳烃的大环,及其分离且结构明确的ArCu(II)和ArCu(III)化合物作为分子工具,我们现在报告了一项深入的实验和计算研究以空气为氧化剂,Cu(II) 催化芳烃和硼酸之间的氧化交叉偶联反应的机理。有机铜化合物与对甲苯基硼酸的化学计量反应验证了芳基铜 (II) 而不是芳基铜 (III) 作为反应性有机金属中间体。XPS、EPR、1H NMR、HRMS 和紫外-可见光谱证据以及所有产物和铜形态的分离和量化,结合对瞬态中间体的电子结构和能量学的计算分析,提出了涉及亲电子金属化的反应序列芳烃通过 Cu(II),芳基硼酸盐金属转移为 ArCu(II),所得的
Synthesis of Functionalized Azacalix[1]arene[3]pyridine Macrocycles from Cu(II)-Mediated Direct Amination Reactions of Arene through High Valent Arylcopper(III) Intermediates
作者:Yang Liu、Qian Zhang、Qing-Hui Guo、Mei-Xiang Wang
DOI:10.1021/acs.joc.6b01448
日期:2016.11.4
presence of K3PO4 under mild conditions, azacalix[1]arene[3]pyridines underwent arene C–H bond amination with a number of sulfonamides, imides, and saccharin to afford the diverse C–N bond forming products. Based on different reactivity between arylcopper(II) and arylcopper(III) compounds toward nitrogen nucleophiles, the reaction proceeded most likely through arene C–H bond metalation via reactive arylcopper(III)
在温和条件下,在K 3 PO 4存在下,由Cu(ClO 4)2介导,对azacalix [1] arene [3]吡啶进行芳烃C-H键胺化反应,并用许多磺酰胺,酰亚胺和糖精进行处理,以提供多种C–N键形成产品。基于芳基铜(II)和芳基铜(III)化合物对氮亲核试剂的不同反应性,该反应最有可能通过芳烃铜键通过反应性芳基铜(III)中间体进行金属化以及它们与源自氮的去质子化的氮阴离子的结合而进行。 p K a的氮亲核试剂的酸性NH键(DMSO)<17.5,然后进行还原消除。该研究不仅提供了方便,直接的途径,以其他方式不易获得的官能化杂芳基芳烃,也丰富了我们对高价有机铜化学的理解。