Rhodium- and Iridium-Catalyzed Allylation of Electron-Rich Arenes with Allyl Tosylate

Abstract

The allylation of electron-rich arenes with allyl tosylate proceeded at 0 °C in the presence of [Rh(nbd)(CH₃CN)₂]PF₆. Various oxygenated arenes were allylated with high para-selectivity in almost all cases. Especially in the reaction of anisoles, the tendency was remarkable.

allylations - arenes - catalysis - iridium - rhodium

References

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11

Reactions with cotyl tosylate and 1-methyl-2-propenyl tosylate should provide some information about the mechanism. However, we were not able to prepare 1-methyl-2-propenyl tosylate because of its instability.

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14

Typical Procedure: To a suspension of an arene (5.0 mmol) and [Rh(nbd)(CH₃CN)₂]PF₆ (0.025 mmol) in dry toluene (1 mL), allyl tosylate (0.5 mmol) was added at 0 °C under an N₂ atmosphere. After stirring for 15 h or 24 h, the mixture was filtered thorough a plug of silica, followed by washing with diethyl ether (ca. 30 mL). The solvent was removed under reduced pressure to give an oil that was further purified by flash column chromatography to yield an allylated product. The products obtained were identified by comparison of their ¹H NMR spectral data with those of commercial or reported samples.