Yang Weiguang, Qiao Rui, Chen Jiuxi, Huang Xiaobo, Liu Miaochang, Gao Wenxia, Ding Jinchang, Wu Huayue
College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China.
J Org Chem. 2015 Jan 2;80(1):482-9. doi: 10.1021/jo5024848. Epub 2014 Dec 11.
A palladium-catalyzed sequential cyclization/C-H activation cascade reaction of 2-amino-N'-arylbenzohydrazides with triethyl orthobenzoates has been developed, providing indazolo[3,2-b]quinazolinones in good to high yields. Two key intermediates of the reaction, 2-phenyl-3-(phenylamino)quinazolinone and C-H insertion palladacycle, were isolated, and their structures were unambiguously confirmed by X-ray crystallography. This method represents an unprecedented example of a halogen-free protocol to access indazolo[3,2-b]quinazolinones. Moreover, this chemistry also provides a useful tool for the discovery of fluorescent materials.
已开发出一种钯催化的2-氨基-N'-芳基苯甲酰肼与原苯甲酸三乙酯的串联环化/C-H活化级联反应，能以良好至高收率得到吲唑并[3,2-b]喹唑啉酮。分离出了该反应的两个关键中间体，即2-苯基-3-(苯基氨基)喹唑啉酮和C-H插入钯环，并通过X射线晶体学明确证实了它们的结构。该方法是获取吲唑并[3,2-b]喹唑啉酮的无卤素方案的一个前所未有的实例。此外，这种化学方法还为荧光材料的发现提供了一种有用的工具。
