Allylic amination, iodine

In a similar way, 2-oxazolidinones and tetrahydro-2//-l, 3-oxazin-2-ones have been prepared by the reaction of primary allyl amines and homoallyl amines10, respectively, with carbon dioxide and iodine in methanol via an intramolecular cyclization. Prolonged reaction for a week in the presence of cesium carbonate increases the yield to 70-90%. This reaction has a large applicability and the ease of the method makes it useful in organic synthesis. 

Benzamidines and trichloroacetamidines, readily prepared from allylic amines and benzonitdle or trichloroacetonitrile, cyclized on treatment with A-iodosuccinimide or iodine in tetrahydro-furan to give the corresponding 4,5-dihydroimidazoles 1 and 2. The successive hydrolysis gave diamines166. 

Vinyl halides add to allylic amines in the presence of Ni(cod)2 where cod=l, 5-cyclooctodine, followed by reduction with sodium borohydride. Aryl iodides add to alkynes using a platinum complex in conjunction with a palladium catalyst. A palladium catalyst has been used alone for the same purpose, and the intramolecular addition of a arene to an aUcene was accomplished with a palladium or a GaCl3 catalyst, " AUcyl iodides add intramolecularly to aUcenes with a titanium catalyst, or to alkynes using indium metal and additives. The latter cyclization of aryl iodides to alkenes was accomplished with indium and iodine or with Sml2. " ... 

PhI(OTf)2 is an effective oxidant for the direct formation of bicyclic diazenium salts from a variety of linear hydrazone precursors. This oxidative cyclization is postulated to occur by the iodine(III)-mediated formation of an l-aza-2-azoniaallene salt intermediate. A direct intermolecular allylic amination has been achieved with up to 99% yields using metal-free conditions. The reaction employs a hypervalent iodine(lll) reagent as an oxidant and bistosylimide as a nitrogen source. Mechanistic studies including isotope labelling and Hammett correlation indicated that depending... 

The bridging chlorine atoms in these ir-allylicpalladium complexes are readily replaced by bromine, iodine, or the thiocyanate group by treatment with the corresponding alkali metal salt in a suitable solvent such as acetone 105, 194). The chlorine bridge is split by amines for example, the ir-allyl complex [PdCl(7r-CsH6)]2, with p-toluidine, gives [PdCl(7r-C3H6) (p-tolui-dine)] as stable, pale yellow crystals (105). 

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