A STUDY ON SYNTHESIS OF HETEROCYCLES VIA CROSS-CONJUGATED HETEROTRIENES AND FUNCTIONALIZED CARBODIIMIDES AS KEY INTERMEDIATES

1.合成了三种新型的交叉共轭杂三烯化合物，并发展了它们的立体选择性二烯传递的杂Diels-Alder反应，用于合成各种稠环杂环化合物，如喹啉、喹唑啉、嘧啶并哒嗪、吡喃并嘧啶、吡喃并吡啶、吡咯并二氮杂非那烯和吡咯并氮杂非那烯。氮杂三烯与反应性亲二烯体如甲苯磺酰异氰酸酯、烯酮和乙烯基醚反应进行初始环加成，这取决于氮杂三烯上的取代基。2.以亚氨基膦与异氰酸酯的氮杂Wittig反应为原料，通过串联环化反应合成了咪唑并喹啉、咪唑并咪唑、咪唑并嘧啶、咪唑并喹唑啉、咪唑并噻嗪、嘧啶并苯并噻嗪、喹唑啉并苯并噻嗪和二氮杂喹啉。它们带有连接另一个官能团如烯烃、炔、邻溴芳烃、几个烯烃或迈克尔受体的酰胺-NH基团。方法[A]包括通过分子内胺-亲核加成至马来酰亚胺-枯烯碳的初始环化，随后通过使新形成的胺基团与排列的内部官能团反应进行第二环化。方法[B]是串联反应，其包括碳亲核试剂的初始分子间加成，随后是新形成的两齿胺或碳亲核试剂中心的第二分子内迈克尔加成，以得到喹唑啉或喹啉。第三种方法是以分子内或分子间的方式将双酰亚胺和烯酮亚胺与炔进行Pauson-Khand型反应，以合成吡咯啉酮衍生物。

1.Three new types of cross-conjugated heterotrienes have been prepared and their stereoselective diene-transmissive hetero Diels-Alder reactions have been developed for the synthesis of a variety of ring-fused heterocycles such as quinolines, quinazolines, pyrimidopyridazines, pyranopyrimidines, pyranopyridines, pyrrolodiazaphenalenes and pyrroloazaphenalenes. The azatrienes reacted for the initial cycloaddition with reactive dienophiles such as tosylisocyanates, ketenes and vinyl ethers, depending on the substituents on the azatrienes. The second cycloaddition underwent normal electron-demanding Diels-Alder reaction with a variety of common dienophiles.2.Tandem cyclizations strategy of functionalized carbodiimides, which were prepared by the aza-Wittig reaction of iminophosphoranes with isocyanates, has been developed for facile synthesis of a variety of ring-fused nitrogen-heterocyclic compounds such as imidazo-quinolines, imidazoimidazoles, imidazopyrimidines, imidazoquinazolines, imidazothiazines, pyrimidobenzothiazines, quinazolinobenzothiazines, and diazepinoquinolines. They bear a amide-NH group tethering another functional group such as an alkene, an alkyne, an o-bromoarene, a couple of alkenes, or a Michael acceptor. The method [A] includes the initial annulation by intramolecular amine-nucleophilic addition to the carbodiimide-cumulene carbon, followed by the second cyclization by reacting a group of newly formed amine with an inner functional group arranged. The method [B] is a tandem reaction that includes an initial intermolecular addition by a carbon nucleophile, followed by a second intramolecular Michael addition of a newly formed ambident amine or carbon nucleophile center to give quinazolines or quinolines. The third method is a Pauson-Khand type reaction of carbodiimides and ketenimines with alkynes in an intramolecular or intermolecular fashion for the synthesis of pyrrolinone derivatives.