ChemInform Abstract: Synthesis and Cyclization of 1‐Methyl‐4‐(3‐(4‐substituted‐phenylamino)propyn‐1‐yl)piperidin‐4‐ols.

Abstract

In the presence of KOH the piperidone (I) adds to the arylaminopropynes (II) to afford the title compounds (III).

Rhodium(I)-Catalyzed Synthesis of Indoles: Amino-Claisen Rearrangement of N-Propargylanilines

“…N -Propargylanilines are alternative candidates for the preparation of heterocycles, since regioselective intramolecular hydroarylation reactions of N -propargylanilines are considered to be divergent methods for the preparation of quinoline or indole frameworks (6- endo or 5- exo ). Intramolecular hydroarylation reactions have been achieved by various metal catalysts, , and the reactions of N -propargylanilines have been known to proceed via the 6- endo mode to give 1,2-dihydroquinolines (path b , Scheme ). , On the other hand, amino-Claisen rearrangements , of N -propargylaniline derivatives, which could be considered to be an alternative route to the quinoline ring system, have been reported to proceed through o -allenylaniline under the thermal or Cu-promoted conditions , (path a′ ). Although a few examples of the thermal rearrangements of N -propargylanilines brought about the formation of indoles (path a ), the reactions required extremely high temperatures (240−260 °C) and the products were obtained in low yields .…”