Palladium-catalyzed heteroannulation of catechol with functionalized propargylic carbonates: Influence of the functional group on the regioselectivity of the cyclization

The palladium(0)-catalyzed annulation of catechol with propargylic carbonates bearing different functionalized groups (hydroxy, tert-butyldimethylsilyloxy, ester, diethylamino) afforded functionalized 2,3-dihydro-2-ylidene-1,4-benzodioxin isomers. The regioselectivity of the cyclization depends strongly on the nature of the substituent and on the chain length between the triple bond and the function.

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