Synthesis of Barbaralones and Bullvalenes Made Easy by Gold Catalysis

The gold(I)-catalyzed oxidative cyclization of 7-ethynyl-1,3,5-cycloheptatrienes gives 1-substituted barbaralones in a general manner, which simplifies the access to other fluxional molecules. As an example, we report the shortest syntheses of bullvalene, phenylbullvalene, and disubstituted bullvalenes, and a readily accessible route to complex cage-type structures by further gold(I)-catalyzed reactions

Gold(I)-Catalyzed Inter- and Intramolecular Additions of Carbonyl Compounds to Allenenes

The gold(I)-catalyzed intramolecular reaction of allenes with oxoalkenes leads to bicyclo[6.3.0]undecane ring systems, although in the case of terminally disubstituted allenes, seven-membered rings are formed. The related intermolecular addition of aldehydes to allenenes also gives seven-membered rings

Exploring the Versatility of 7‐Alkynylcycloheptatriene Scaffolds Under π‐Acid Catalysis

International audienceThe reactivity of 7‐alkynycycloheptatrienes tethered to an aryl group under π‐acid catalysis has been studied. A variety of useful cyclic products were synthesized via Au(I)‐catalyzed skeletal reorganization, Cu(II)‐catalyzed hydroarylation, or Brønsted acid‐catalyzed tandem hydroarylation/Friedel‐Crafts reaction. We also report a rare type of skeletal reorganization involving the 1,3‐acetonide tether in the presence of a univalent cationic Ga(I) + complex