A Novel and Efficient Method for the Synthesis of α-Azidoketones and α-Ketothiocyanates
作者:J. S. Yadav、B. V. Subba Reddy、M. Srinivas
DOI:10.1246/cl.2004.882
日期:2004.7
α-Diazoketones underwent insertion smoothly with sodium azide and potassium thiocyanate in the presence of CeCl3·7H2O under mild reaction conditions to afford the corresponding α-azidoketones and α-ketothiocyanates in excellent yields.
Selective alkylation of indazoles is still a highly challenging topic in chemistry and the synthesis of important molecules. Herein, a novel highly selective N2-alkylation of indazoles with diazo compounds is described in the presence of TfOH. Unlike the traditional metal- and base-catalysed version, this protocol highlights the regioselectivity of alkylation of indazoles and a metal-free catalysis
吲唑的选择性烷基化仍然是化学和重要分子合成中极具挑战性的课题。在此,描述了在 TfOH 存在下,吲唑与重氮化合物的新型高选择性N 2 -烷基化。与传统的金属和碱催化版本不同,该方案突出了吲唑烷基化的区域选择性和无金属催化体系,以高区域选择性( N 2 / N 1高达 100/0) 和出色的官能团耐受性。此外,成功地进行了克级合成以产生相应的产物。通过控制实验进行的机械研究提供了合理的机械建议。
TfOH-Catalyzed Regioselective S–H Insertion of Cyclic Thioamide Derivatives with Diazo Compounds at Room Temperature
We have developed a method for highly regioselective S–H bond insertion reactions of various diazo compounds and cyclic thioamide derivatives at room temperature. These reactions provide straightforwardaccess to alkylated benzimidazoles, benzothiazoles, and benzoxazoles. This mild method uses readily available TfOH as a catalyst and features a broad substrate scope, good functional group tolerance
Pyrazoline bisphosphonate esters as novel antiinflammatory and antiarthritic agents
作者:Richard A. Nugent、Megan Murphy、Stephen T. Schlachter、Colin J. Dunn、Robert J. Smith、Nigel D. Staite、Louise A. Galinet、Sharon K. Shields、Danielle G. Aspar、Karen A. Richard、Norman A. Rohloff
DOI:10.1021/jm00053a017
日期:1993.1
Vinylidenebisphosphonic acid tetraethyl ester (1) and diazo ketones 7a-1 in ether at 22-degrees-C yield pyrazoline bisphosphonate tetraethyl esters 8a-1 in moderate to good yield. These compounds were evaluated in animal models of arthritis: rat adjuvant induced polyarthritis (AIP) and murine antigen-induced arthritis (AIA) and a murine model of chronic inflammation, the delayed type hypersensitivity granuloma reaction (DTH-GRA). (5-Benzoyl-2,4-dihydro-3H-pyrazol-3-ylidene)-bisphosphonic acid tetraethyl ester (8a), and [5-(3-fluorobenzoyl)-2,4-dihydro-3H-pyrazol-3-ylidene)bisphosphonic acid tetraethyl ester (8d) significantly inhibited the arthritis models, AIP (15 mg/kg) and AIA (25 mg/kg), as well as the DTH-GRA (25 mg/kg). Conversion of 8a to the corresponding bisphosphonic acid, 10a, resulted in loss of activity Compounds with alkyl substituents on the pyrazoline nitrogen, 9a-d, were inactive in the DTH-GRA. These results show that 8a and 8d have novel antiinflammatory activity and are capable of inhibiting chronic arthritis and inflammation in animals. Such compounds might be in man for treating chronic tissue injury associated with arthropathies such as inflammatory joint disease as well as other chronic inflammatory diseases.
InBr3/Cu(OTf)2-catalyzed C-alkylation of pyrroles and indoles with α-diazocarbonyl compounds
作者:J.S. Yadav、B.V.S. Reddy、G. Satheesh
DOI:10.1016/j.tetlet.2003.09.031
日期:2003.11
Pyrroles and indoles react smoothly with alpha-diazocarbonyl compounds in the presence of 10 mol%, of InBr3, under mild conditions to afford the corresponding 2- and 3-alkyl pyrrole and 3-alkyl indole derivatives, respectively, in good yields with high selectivity. (C) 2003 Elsevier Ltd. All rights reserved.