628707-01-7Relevant academic research and scientific papers
Studies concerning the electrophilic amino-alkene cyclisation for the synthesis of bicyclic amines
Klein, Johannes E. M. N.,Mueller-Bunz, Helge,Evans, Paul
supporting information; experimental part, p. 986 - 995 (2009/05/30)
The bromination of a series of cyclohexenyl substituted secondary amines 1a-i has been investigated using Br2, PHT and NBS. In the case of Br2 and NBS the secondary amines preferentially undergo N-bromination. In contrast, PHT cleanly affords the products of alkene dibromination. In the case of Br2 the N-bromo species then give the products of alkene dibromination, albeit less efficiently. On subsequent treatment with K2CO3 these dibromides form the corresponding hexahydroindoles 2a-h and octahydroquinoline 2i. The presence of an N-substituent bearing a stereogenic centre (1h and 1i) was studied and the products 2h and 2i were isolated with no diastereoselectivity. When NBS was used a novel cyclisation, forming bromo-substituted octahydroindoles 9a,b and d, was observed. In relation to this sequence it was shown that these products were not intermediates in the former Br2/PHT processes and that the reaction only proceeded in the presence of the succinimide by-product of N-bromination.
A facile aminocyclization for the synthesis of pyrrolidine and piperidine derivatives
Shao, Zhihui,Chen, Jingbo,Tu, Yongqiang,Li, Liang,Zhang, Hongbin
, p. 1918 - 1919 (2007/10/03)
Bromination of an isolated double bond followed by aminocyclization furnishes a highly stereoselective protocol for the intramolecular formation of pyrrolidine and piperidine ring containing subunits that are presented in numerous biologically active natu
