Synthesis of 4<i>H</i>-3,1-Benzoxazines, Quinazolin-2-ones, and Quinoline-4-ones by Palladium-Catalyzed Oxidative Carbonylation of 2-Ethynylaniline Derivatives
作者:Mirco Costa、Nicola Della Cà、Bartolo Gabriele、Chiara Massera、Giuseppe Salerno、Matteo Soliani
DOI:10.1021/jo0357770
日期:2004.4.1
presence of catalytic amounts of 10% Pd/C in conjunction with Bu4NI and KF and under 2.4 MPa of a 3:1 mixture of CO and air. Anti and syn 6-exo-dig cyclization modes account for the formation of the two stereoisomers. Isomerization of the vinylpalladium intermediate may occur as well. Formation of a double carbonylation product 7r and of a gem-dimethoxycarbonylation product 6s, whose structures have been
通过钯催化的各种取代基的环化-烷氧基羰基化反应,可以有效而直接地合成4 H -3,1-苯并恶嗪3和4,喹唑啉-2-酮5和喹啉-4-酮衍生物6和7。 2-(三甲基硅烷基)乙炔基苯胺或脲衍生物2。反应在65或75°C的7:1 MeCN / MeOH中,在催化量为10%Pd / C的情况下,与Bu 4 NI和KF一起在2.4 MPa的CO和3:1的混合物下进行空气。反和Syn 6 -exo-dig环化模式说明了两种立体异构体的形成。乙烯基钯中间体的异构化也可能发生。通过不寻常的重排可以证明双羰基化产物7r和宝石-二甲氧基羰基化产物6s的形成,其结构已经通过X射线衍射分析确定。