A novel palladium-catalyzed interannular selective C-H silylation of 1,1'-biaryl-2-acetamides is described. The combination of palladium catalyst with copper oxidant enables meta- or ortho-selective C-H silylation by employing hexamethyldisilane as a trimethylsilyl source, which relies on the control of NBE derivatives as a switch, thus providing straightforward access to divergent silicon-containing 1,1'-biaryl-2-acetamides.
Ruthenium-catalyzed ortho-arylation of acetanilides with aromatic boronic acids: an easy route to prepare phenanthridines and carbazoles
作者:Ravi Kiran Chinnagolla、Masilamani Jeganmohan
DOI:10.1039/c3cc49398a
日期:——
A regioselective ruthenium-catalyzed ortho-arylation of acetanilides with aromatic boronic acids is described. Later, ortho-arylated acetanilides were converted into phenanthridine and carbazole derivatives.
AbstractAn in situ generated cationic ruthenium(II) catalyst allowed for robust CH arylations of anilides with boronic acids. The optimized ruthenium catalyst was found to be both site selective and chemoselective, thereby providing the monoarylated products in excellent yields with ample substrate scope. The catalyst’s high efficacy furthermore set the stage for efficient CH arylations with borinic acids as well as potassium trifluoroborates.magnified image
作者:Wenguang Li、Wenqi Chen、Bang Zhou、Yankun Xu、Guobo Deng、Yun Liang、Yuan Yang
DOI:10.1021/acs.orglett.9b00690
日期:2019.4.19
A novel palladium-catalyzed interannular selective C-H silylation of 1,1'-biaryl-2-acetamides is described. The combination of palladium catalyst with copper oxidant enables meta- or ortho-selective C-H silylation by employing hexamethyldisilane as a trimethylsilyl source, which relies on the control of NBE derivatives as a switch, thus providing straightforward access to divergent silicon-containing 1,1'-biaryl-2-acetamides.
Intramolecular Oxidative C−N Bond Formation for the Synthesis of Carbazoles: Comparison of Reactivity between the Copper-Catalyzed and Metal-Free Conditions
作者:Seung Hwan Cho、Jungho Yoon、Sukbok Chang
DOI:10.1021/ja111652v
日期:2011.4.20
New synthetic procedures for intramolecular oxidative C-N bondformation have been developed for the preparation of carbazoles starting from N-substituted amidobiphenyls under either Cu-catalyzed or metal-freeconditions using hypervalent iodine(III) as an oxidant. Whereas iodobenzene diacetate or bis(trifluoroacetoxy)iodobenzene alone undergoes the reaction to provide carbazole products in moderate
已经开发了用于分子内氧化 CN 键形成的新合成程序,用于在 Cu 催化或无金属条件下使用高价碘 (III) 作为氧化剂从 N 取代的酰氨基联苯制备咔唑。虽然二乙酸碘苯或双(三氟乙酰氧基)碘苯单独进行反应以提供中低收率的咔唑产物,但三氟甲磺酸铜(II)和碘(III)物质的组合使用显着提高了反应效率,提供了更多样化的范围产品良率高。在包括动力学曲线、同位素效应和自由基抑制实验在内的机理研究的基础上,铜物种被提议用于催化激活高价碘 (III) 氧化剂。