Synthesis of 5H-Pyrazino[2,3-b]indoles from Indole-2,3-dione Derivatives.
摘要:
Reaction of N-acetylindol-2,3-diones with ethylenediamines gave the dihydro-pyrazinones 11, which could, after dehydrogenation and deacetylation be transformed to the corresponding 5H-pyrazino[2,3-b]indoles 5. N,N-Dimethylaminoethylation of the anion of 5 occurred selectively in the 5-position. Thermolysis of 1-pyrazinylbenzotriazole gave pyrazino[1,2-a]-benzimidazole 33 and no 5H-pyrazino[2,3-b] indole.
yields. A proposed mechanism involving initial formation of a spiro compound is given. This isolable intermediate subsequently rearranges via a sequential isocyanate ring opening and a cyclisation process to a urea derivative which finally cyclized to the indolo[3,2-c]quinolin-6-ones. The urea derivative could be prepared separately and cyclized selectively to indolo[3,2-c]quinolin-6-one. Reaction of N-acetylisatin
等摩尔量的2-氨基苄胺和靛红在乙酸中的回流以良好的产率产生了吲哚[3,2 - c ]喹啉-6-酮。提出了一种涉及螺环化合物初始形成的机制。该可分离的中间体随后通过顺序的异氰酸酯开环和环化过程重排为脲衍生物,该脲衍生物最终环化为吲哚[3,2 - c ]喹啉-6-酮。尿素衍生物可单独制备并选择性环化为吲哚[3,2- c]喹啉-6一。N-乙酰基Isatin与2-氨基苄基胺在室温下反应生成1,4-苯并二氮杂酮3-(2-乙酰氨基苯基)-1,5-二氢-1,4-苯并二氮杂-2-酮,而其异构体2(2-乙酰氨基苯并室温下由2-(2-乙酰氨基苯基)-N-(2-氨基苄基)-2-氧乙酰胺在乙酸中获得)-4,5-二氢-1,4-苯并二氮杂-3-酮。
Phosphine-Catalyzed (4 + 1) Annulation of <i>o</i>-Hydroxyphenyl and <i>o</i>-Aminophenyl Ketones with Allylic Carbonates: Syntheses and Transformations of 3-Hydroxy-2,3-Disubstituted Dihydrobenzofurans and Indolines
作者:Zifeng Qin、Wei Liu、Danyang Wang、Zhengjie He
DOI:10.1021/acs.joc.6b00596
日期:2016.6.3
A phosphine-catalyzed (4 + 1) annulationreaction of o-hydroxyphenyl and o-aminophenyl ketones with ester-modified allylic carbonates has been developed, providing a facile and efficient method to synthesize functionalized 2,3-disubstituted dihydrobenzofurans and indolines. Under mild conditions and in the catalysis of PPh3 (20 mol %), the reactions of o-hydroxyphenyl or o-aminophenyl ketones readily