Platinum-Catalyzed Dehydroalkoxylation-Cyclization Cascade via N-O Bond Cleavage
Platinum-Catalyzed Dehydroalkoxylation-Cyclization Cascade via N-O Bond Cleavage
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DOI：
10.1021/ja900174t
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发表时间：
2009-04-01
影响因子：
15
通讯作者：
Terada, Masahiro
中科院分区：
文献类型：
--
作者：
Nakamura, Itaru;Sato, Yusuke;Terada, Masahiro
将氮原子上带有烷氧基和芳基的邻炔基苯基脲和乙酰胺 1 进行铂催化环化反应，通过 N-O 键断裂得到相应的四环化合物 2，收率良好至优异。例如，N-甲氧基-N'-甲基-N'-(2-(戊-1-炔基)苯基)-N-苯基脲(1a)在Ptl(4)(10mol%)存在下在1,4-二恶烷中于100℃反应12小时，得到5-甲基-12-丙基吲哚并[1,2-c]喹唑啉-6(5H)-酮(2a) 通过亚胺结合的铂类胡萝卜素中间体，然后进行芳香族 C-H 插入，产率达到 93%。
ortho-Alkynylphenylureas and -acetamides 1, with an alkoxy and aryl group on the nitrogen atom, were subjected to platinum-catalyzed cyclization reactions to afford the corresponding tetracyclic compounds 2, via N-O bond cleavage, in good to excellent yields. For example, N-methoxy-N'-methyt-N'-(2-(pent-1-ynyl)phenyl)-N-phenylurea (1a) was reacted for 12 h in the presence of Ptl(4) (10 mol%) in 1,4-dioxane at 100 degrees C to afford 5-methyl-12-propytindolo[1,2-c]quinazolin-6(5H)-one (2a) in 93% yield, via an iminium-bound platinum carbenoid intermediate, followed by an aromatic C-H insertion.