Amines chloro, from alkenes

Adenosine analogues where the furanose ring was replaced with alternative dihydro- and tetrahydrofurans were prepared from 6-chloro-9-(4-methylenetetrahydrofuran-3-yl)-9/7-purine <2002T4865>. Of particular interest was the transformation of the exocyclic alkene on the THF ring first by dihydroxylation, then elimination to yield (4-(6-aminopurin-9-yl)-2,5-dihydrofuran-3-yl)methanol after amination of the purine ring at C-6. This A-alkenylpurine was reduced (Pd/C, H2, 25 psi, 73% yield) to provide the tetrahydrofuran-3-yl derivative. 

The reaction of aryl azides with alkenes in the presence of aluminum trichloride gave different products depending on the structure and the geometry of the alkene, the reaction proceeds via the intermediacy of an aziridine 8 complexed with the Lewis acid. Thus aziridines 9 were cleanly obtained from cycloheptene and (Z)-cyclooctene, however, from cyclopentene and cyclohexene a mixture of allylic amines 10 and /5-chloro amines 11 was produced86- 87. The use of 4-chlorophenyl azide in the reaction with cyclohexene gave only a tar. 

Many reactions of amines with palladium- and platinum-olefin complexes have been reported. Akermark showed that nucleophiles add to palladium-olefin complexes to generate aminoalkyl complexes, as shown by the example in Equation 11.26. In this case, reactions of a bis-olefin dichloropalladium complex with amines occurs by splitting of the chloro-bridged dimer by the first equivalent of amine to give a neutral olefin-ligated palladium-amine complex that undergoes attack of the coordinated alkene by a second equivalent of amine. The stereochemistry of the amination is cleanly trans. Akermark and Zetterberg isolated and characterized by C NMR spectroscopy the a-alkyl complexes formed by the amination of both cis- and frans-2-butene, and the stereochemistry of the product alkyl complexes results from external attack by amines, as shown in Scheme 11.5. 

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