Rh(III)-Catalyzed spiroannulation of ketimines with cyclopropenones via sequential C-H/C-C bond activation.

An unprecedented Rh(III)-catalyzed [3+3]-spiroannulation of ketimines with cyclopropenones to access spiro[4,5]dienones has been developed. Sequential C-H/C-C bond activation and subsequent nucleophilic addition are disclosed in this process. This procedure represents the first example of the construction of spirolactams utilising cyclopropenones as 3C synthons. The remarkable advantages of this protocol are excellent chemo- and regio-selectivity, wide functional group tolerance, high reaction yields, and tolerance towards H 2 O.