Gold Catalyzed Cyclopropanation/[5+3] Cycloaddition of 1,4,9‐ and 1,4,10‐Allenenynes to Bicyclo[3.3.1]nonane Derivatives

A synthetic method to prepare cycloalkyl‐ and (hetero)aryl‐fused bicyclo[3.3.1]nonane derivatives from gold(I)‐catalyzed cyclopropanation/[5+3] cycloaddition of 1,4,9‐ and 1,4,10‐allenenynes is described. The suggested double cycloisomerization mechanism delineates the first example of a stepwise [5+3] cycloaddition pathway in gold catalysis, a mode of reactivity that is also sparse in organic chemistry. Experimental and Density Functional...