کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5223798 | 1383498 | 2010 | 17 صفحه PDF | دانلود رایگان |
Cyclisations of homoallylic sulfonamides proceed smoothly via carbenium ion generation using trifluoromethanesulfonic (triflic) acid, the ease of cyclisation being directly related to the ion stability to give good to excellent yields of the corresponding pyrrolidines. Both toluene- and nitrophenyl-sulfonyl groups are suitable for all substrates tested whereas the corresponding carbamates are only useful in cases of tertiary and highly stabilised carbenium ions. Polyene-derived sulfonamides can also be cyclised to the corresponding polycyclic systems in remarkably high yields, in reactions reminiscent of related cascades encountered in terpene biosynthesis.
Cyclisations of homoallylic sulfonamides, both tosyl and nosyl, proceed smoothly via carbenium ion generation using trifluoromethanesulfonic (triflic) acid, the ease of cyclisation being directly related to the ion stability, to give good to excellent yields of the corresponding pyrrolidines. Polyene-derived sulfonamides can also be cyclised to the corresponding polycyclic systems in remarkably efficient cascade reactions.
Journal: Tetrahedron - Volume 66, Issue 23, 5 June 2010, Pages 4150-4166