We discuss a novel selenium-based reaction mechanism consisting in a selenoxide elimination-triggered enamine hydrolysis. This one-pot model reaction was studied for a set of substrates. Underoxidativeconditions, we observed and characterized the formation of primary and secondary amines as elimination products of such compounds, paving the way for a novel strategy to selectively release bioactive
A simple and mild azido-phenylselenenylation of terminal alkenes, which proceeds with complete anti-Markovnikov regioselectivity, has been developed. This reaction occurs when the alkenes are treated with (diacetoxyiodo)benzene, sodium azide, and diphenyl diselenide in dichloromethane at room temperature. The observed regioselectivity can be explained by assuming that the addition process is initiated by azido radicals. This was further supported by the results obtained starting from 1,6-heptadiene and from beta-pinene. Under the same conditions, efficient azido-phenylselenenylation of symmetrical olefins, 3,4-dihydro-2H-pyran, methyl acrylate, and vinyl crotonate can also be effected.
Pyrrolidines from olefins via radical cyclization
作者:Vijay Gupta、Magnus Besev、Lars Engman
DOI:10.1016/s0040-4039(98)00217-2
日期:1998.4
2,4-Disubstituted N-tosylpyrrolidines were prepared from olefins via N-tosylaziridination, benseneselenolate ring-opening and reductive radical cyclization. Azidoselenation of olefins, followed by reduction, N-tosylation, N-allylation and reductive radical cyclization, afforded 3,4-disubstituted N-tosylpyrrolidines. (C) 1998 Elsevier Science Ltd. All rights reserved.