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Please login to access the full content or check if you have access via46.6.1.1 Variation 1: 1,4-Disubstituted E,E-1,3-Dienes by [2C + 2C] Alkenyl–Alkenyl Coupling via Organoboron Migratory Insertion Reactions
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Negishi, E.; Wang, G., Science of Synthesis, (2009) 46, 245.
Selective monohydroboration of 1-chloroalk-1-ynes with thexylborane (1,1,2-trimethylpropylborane), followed by a second hydroboration of alk-1-ynes, produces the corresponding dialkenyl(thexyl)boranes. Their treatment first with sodium methoxide and then with 2-methylpropanoic acid produces 98–99% stereomerically pure E,E-1,3-dienes in 45–55% overall yields, thereby providing most probably the first highly selective and potentially general route to E,E-1,3-dienes (Scheme 9).[1] This one-pot synthesis of E,E-1,3-dienes from an alk-1-yne and a 1-chloroalk-1-yne is efficient, selective, and potentially general, but it has not been widely used, perhaps because of the later development of palladium-catalyzed cross-coupling routes to the same class of compounds.
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References
[1] | Meeeeee, M.; Meeeeee, M., M. Meee. Mee., Meee. Meeeee., (8888), 888. |
[9] | Meeeeee, M.; Meeeeeee, M. M.; Meeeeee, M., M. Me. Meee. Mee., (8888) 88, 8888. |
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