Carbenes from vilsmeier reagents by the action of bases in POCl3; the umpolung of vilsmeier reagents
作者:Ying Cheng、Simon Goon、Otto Meth-Cohn
DOI:10.1039/cc9960001395
日期:——
When para-substituted N-methylformanilides are treated in POCl3 with a base, the corresponding Vilsmeier reagent formed undergoes ready deprotonation to give an aminochlorocarbene from which a range of products derive; a carba- moyl chloride, N-methylisatins, dimers [1,2-dichloro-1,2- bis(N-methyl-N-arylamino)ethenes], trimers 5,10-dimethyl- 11-(N-methyl-N-arylamino)-10H-indolo[3,2-b]quinolinium and 5,10-dimethyl-10H-indolo[3,2-b]quinolinium salts} and tetramers [1,1′-dimethyl-3,3′-bis(N-methyl-N-arylamino)-2,2-biindolyl] are isolated, depending upon the base used and the para-substituent.
当对位取代的N-甲基苯乙酰胺在POCl3和碱的作用下处理时,形成的相应维尔斯梅尔试剂迅速去质子化,生成氨基氯卡宾,进而衍生出一系列产物;包括氨基氯化物、N-甲基异靛酮、二聚体[1,2-二氯-1,2-双(N-甲基-N-芳基氨基)乙烯]、三聚体5,10-二甲基-11-(N-甲基-N-芳基氨基)-10H-吲哚[3,2-b]喹啉和5,10-二甲基-10H-吲哚[3,2-b]喹啉盐}以及四聚体[1,1'-二甲基-3,3'-双(N-甲基-N-芳基氨基)-2,2-双吲哚基],这些产物的形成依赖于所用的碱和对位取代基。