Gold-catalyzed intermolecular coupling of sulfonylacetylene with allyl ethers: [3,3]- and [1,3]-rearrangements.

Gold-catalyzed intermolecular couplings of sulfonylacetylenes with allyl ethers are reported. A cooperative polarization of alkynes both by a gold catalyst and a sulfonyl substituent resulted in an efficient intermolecular tandem carboalkoxylation. Reactions of linear allyl ethers are consistent with the [3,3]-sigmatropic rearrangement mechanism, while those of branched allyl ethers provided [3,3]- and [1,3]-rearrangement products through the formation of a tight ion-dipole pair.

Entry to ß-alkoxyacrylates via gold-catalyzed intermolecular coupling of alkynoates and allylic ethers.

The first gold-catalyzed intermolecular coupling of alkynoates and allylic ethers invoking alkoxy addition and [3,3]-sigmatropic rearrangement as the key mechanism has been developed. Remarkably, the reaction showed complete chemoselectivity toward the pathway initiated by the alkoxy addition to alkynes. This unprecedented reactivity led to a new access to diversely substituted ß-alkoxyacrylates in a highly efficient manner.