Addition of amines to butadiene in alkali metals or lithiumdiethylamide (LiNEt
2) -hexamethylphosphoric triamide (HMPA) systems was studied. In the case of dialkylamines in alkali metals-HMPA systems, the main products were dialkylamino-
trans-2-butene and dialkylamino-2-vinyl-4-hexene.
When excess amounts of an amine was added, the product obtained was a 1 : 1 adduct of butadiene and the amine, which was a mixture of
trans-isomer (8386%),
cis-isomer (39%) and vinyl-isomer (812%).
The yield of dialkylamino-2-vinyl-4-hexenes increased with the ionic radii of alkali metals employed, that is, Li<Na<K.
When LiNEt
2 was used in place of Li, and a small ammount of HMPA was added to LiNEt
2, the
trans-isomer of the 1 : 1 adduct was the main product.
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