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Tin‐Mediated Free‐Radical Cyclization of β‐Allenylbenzoyloximes
Author(s) -
Depature Michaël,
Diewok Josef,
Grimaldi Jacques,
Hatem Jacques
Publication year - 2000
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(200001)2000:2<275::aid-ejoc275>3.0.co;2-r
Subject(s) - chemistry , tin , radical cyclization , free radical reaction , radical , combinatorial chemistry , organic chemistry
A set of allene‐tethered benzoyloximes ( 5 ) has been treated with n Bu 3 SnH. Depending on their substitution pattern, a wide range of compounds has been obtained. If the stannyl radical adds on the allene, the C ‐centred radical thus formed undergoes either a 5‐ exo ring closure to give the cyclopentene derivatives 7 or a 6‐ endo ring closure onto the N atom to give the dihydropyridines 8 . If the stannyl radical adds on the benzoyl moiety, an iminyl radical is formed which leads to the 3 H ‐pyrroles 9 and the alkylidene‐pyrrolines 10 . Steric effects as well as polar effects are the factors governing the reaction course.