Regio-and Stereoselective Synthesis of (E)-1-Alkylseleno-1, 4-Pentadienes by Cross-Coupling of Allyl Bromide with Alkyl-selenovinylcoppers from Alkylselenovinyldialkylboranes

Abstract

Alkylselenovinyldialkylborane derivatives, obtained by hydroboration of terminal alkylselenoacetylenes 1 with dialkylboranes 2, were treated at -15°C with sodium methoxide and cuprous bromide-methyl sulfide to generate alkylselenovinylcopper intermediates which underwent stereospecific cross-coupling with allyl bromide to yield (E)-1-alkylseleno-1, 4-pentadienes 3. The compounds 3 were formed with retention of configuration predetermined from the stereochemistry of the initial alkylselenovinylboranes.