Cascade Reactions of Other Alkynes

SCHEME 4A0 Gold-catalyzed aUtyne hydroamination/ammlation/aromatization cascade. 

SCHEME 4.31 Gold-catalyzed tetrahydropyran synthesis from homopropargylic ethers. 

SCHEME 4.32 Au(I)-catalyzed formation of A-acyl iminium ion and the subsequent 

Notably, the reaction is not prevented by the basic amine, suggesting that the initial gold-catalyzed cycUzation must be facile. 149 can then proceed through Lewis acid-or Brpnsted add-catalyzed formation of the N-acyl iminium ion 150, which cyclizes to yield the final product 147 in an excellent yield. 

SCHEME 433 Au(I)-catalyzed synthesis of functionalized bicyclo[3.2.0]heptanes. 

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