Fröhner Wolfgang, Monse Barbara, Braxmeier Tobias M, Casiraghi Laura, Sahagún Heidi, Seneci Pierfausto
Chemistry Department, Sirenade Pharmaceuticals AG, Am Klopferspitz 19a, D-82152 Martinsried, Germany.
Org Lett. 2005 Oct 13;7(21):4573-6. doi: 10.1021/ol051550a.
[reactions: see text] Two complementary and efficient strategies have been developed for the regiospecific synthesis of unsymmetrical indolopyrrolocarbazoles (IPCs) mono-N-substituted with a pentacycle. A halogen in position 2 of the intermediate bisindolylmaleimides 3a-e allows a selective Mitsunobu coupling by exploiting the increased acidity of the 2-chloro-substituted indole nitrogen. It also promotes an easier cyclization of bisindolylmaleimides 4a-e and 7b-e to IPCs. Alkylation of the 2-unsubstituted indole-3-carboxamides 2a,b and further processing to the corresponding IPCs gives access to the opposite regioisomers.
[反应：见正文] 已开发出两种互补且高效的策略，用于区域特异性合成单-N-被五环取代的不对称吲哚并吡咯并咔唑（IPC）。中间体双吲哚基马来酰亚胺3a - e的2位卤素通过利用2 - 氯取代吲哚氮增加的酸度实现选择性光延反应偶联。它还促进双吲哚基马来酰亚胺4a - e和7b - e更容易环化生成IPC。2 - 未取代的吲哚 - 3 - 甲酰胺2a、b的烷基化以及进一步加工成相应的IPC可得到相反的区域异构体。
