Science of Synthesis

Arndtsen, B. A.; Tjutrins, J., Science of Synthesis: Multicomponent Reactions, (2014) 2, 476.

Balme has reported the palladium-catalyzed multicomponent synthesis of 3-methylene-substituted tetrahydrofuran derivatives from aryl halides, propargylic alcohols, and electron-poor alkenes (‌Scheme 2‌).[‌18‌] This reaction is believed to proceed via the initial coupling of the propargyl alcohol and the alkene, followed by cyclization prior to reductive elimination. Dichlorobis(triphenylphosphine)palladium(II) catalyzes this process with high selectivity. A range of substrates can be employed, although α-substituted propargyl alcohols often yield mixtures of diastereomers. A less versatile variation of this method employs allylic alcohols rather than propargylic alcohols, leading to methyltetrahydrofurans.[‌19‌]

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References