107657-96-5Relevant academic research and scientific papers
Catalytic cycloisomerization of unsaturated organoiodides
Bailey, William F.,Carson, Matthew W.
, p. 9960 - 9967 (2007/10/03)
Catalytic quantities of phenyllithium (PhLi) have been found to initiate novel 5-exo cycloisomerization of a variety of structurally diverse unsaturated organoiodides. The isomerization reaction appears to be a process of broad synthetic utility for the preparation of iodomethyl-substituted five-membered rings. Primary, secondary, tertiary, or aryl iodides tethered to a suitably positioned carbon-carbon π-bond are converted cleanly to their cyclic isomers in good to excellent yield (i.e., 70-90%) by simply allowing a hydrocarbon-MTBE solution of the iodide to stand in the presence of a small quantity of PhLi at an appropriate temperature. The mechanism of the cycloisomerization was found to be substrate dependent: unsaturated aryl and primary alkyl iodides undergo isomerization via a three-step cascades (eqs 1- 3) mediated by two reversible lithium-iodine exchange reactions bracketing an irreversible 5-exo cyclization of an unsaturated organolithium; unsaturated secondary and tertiary alkyl iodides apparently isomerize via a radical- mediated atom transfer process initiated by homolytic fragmentation of the ate-complex generated upon attack of PhLi on the iodine atom of the substrate.
Iododediazoniation of Arenediazonium Salts Accompanied by Aryl Radical Ring Closure
Beckwith, Athelstan L. J.,Meijs, Gordon F.
, p. 1922 - 1930 (2007/10/02)
Treatment of o-(allyloxy)benzenediazonium tetrafluoroborate (1a) with sodium iodide in acetone affords the cyclized iodide 2a in good yield by a mechanism involving the generation and exo cyclization of the aryl radical 6a.Other diazonium salts (1b-i) containing suitable unsaturated side chains behave similarly, but those (1l,1m) in which there is an N-allylsulfonamido group yield mainly products formed by endo cyclization.The diazonium salts 1j and 1k do not give cyclized products.Factors affecting the mechanism, rates, and regiochemistry of the reaction are discussed.
