Direct Access to 9/6‐Fused Cycles via Sequential Hydride Shift Mediated Double C(<i>sp</i>³)−H Bond Functionalization

Abstract

Abstract We have developed a sequential hydride shift process involving a [1,8]‐hydride shift. When cinnamylidene malonates having a biphenyl core were treated with 30 mol% Yb(OTf) 3 and 10 mol% i Pr 2 NEt, the desired sequential [1,8]‐[1,5]‐hydride shift process proceeded smoothly to afford synthetically challenging nine‐membered carbocycle‐fused piperidine derivatives in good chemical yields (up to 77%). Notably, the desired nine‐membered carbocycles could not be obtained by a single [1,8]‐hydride shift/cyclization process, suggesting that the employment of the sequential system is crucial to achieving the reaction. magnified image

Topics & Concepts