Bronsted Acid-Catalyzed Enantioselective Iodocycloetherification Enabled by Triphenylphosphine Selenide Cocatalysis

Enantioselective iodocycloetherifications can be conducted using sterically highly demanding BINOL-based phosphoric acid diesters as catalyst. To achieve highly enantioselective reactions, cocatalysis by triphenylphosphine selenide is necessary. With cocatalysis, good to excellent enantioselectivities can be achieved for a broad range of substrates using catalyst and cocatalyst loadings as low as 1 mol %. The triphenylphosphine selenide cocatalyst itself does not strongly influence diastereoselectivity, but leads to higher reactivity and, in combination with a BINOL-based phosphoric acid diester, to good enantioselectivity.

Automated summary

Enantioselective iodocycloetherifications can be achieved using sterically highly demanding BINOL-based phosphoric acid diesters as catalyst, requiring cocatalysis by triphenylphosphine selenide. Good to excellent enantioselectivities can be achieved for a broad range of substrates with low catalyst and cocatalyst loadings of 1 mol %. Triphenylphosphine selenide itself does not strongly impact diastereoselectivity, but improves reactivity and enhances enantioselectivity when combined with a BINOL-based phosphoric acid diester.