Departamento de Química, Universidade Estadual de Maringá (UEM), 87030-900, Maringá, PR, Brazil.
Departamento de Química, Universidade Federal de Santa Maria (UFSM), 97110-970 - Santa Maria, RS, Brazil.
Org Biomol Chem. 2020 Apr 1;18(13):2524-2537. doi: 10.1039/d0ob00319k.
A simple and efficient methodology for highly regioselective synthesis of azomethine pyrazoles and isoxazoles containing a trifluoromethyl group is reported. The cyclocondensation of trifluoromethylated β-enamino diketones (TBED) with phenylhydrazine and hydroxylamine hydrochloride, in the presence of BF3, provided 5-aryl-4-[(tert-butyl)iminomethyl]-3-trifluoromethylazoles by aza-Michael-type 1,2-addition. The scope of the reaction was expanded by transimination with arylamines in a one-pot method starting from TBED. Thus, 83 novel 4-[(alkyl/aryl)iminomethyl]-3-trifluoromethylazoles were obtained with high regioselectivity and in yields of 51 to 89%.
报道了一种简单高效的方法，用于高区域选择性合成含三氟甲基的亚胺基吡唑和异噁唑。在 BF3 的存在下，三氟甲基化的β-烯氨基二酮（TBED）与苯肼和盐酸羟胺环缩合，通过氮杂迈克尔型 1,2-加成得到 5-芳基-4-[(叔丁基)亚氨基甲基]-3-三氟甲基唑。通过从 TBED 开始的一锅法与芳胺进行转亚胺化反应，扩展了反应的范围。因此，以高区域选择性和 51%至 89%的产率获得了 83 种新型 4-[(烷基/芳基)亚氨基甲基]-3-三氟甲基唑。
