Cope rearrangement palladium catalysis

Several mechanisms have been proposed for palladium catalysis of Cope rearrangements. Overman, who has examined metal ion catalysis of a number of 3,3-sigmatropic rearrangements, considers this an... 

Discovered in 1966/ " the Pd(II)-promoted" and Pd(II)-catalyzed " Cope rearrangement has become an important tool in synthetic endeavors. Catalysis of the Cope rearrangement by palladium salts such as PdCl2 provides rate enhancements as high as 10 while also offering higher levels of stereoselectivity than their thermal counterparts.In one of the early examples described by Overman, a predominant contributor in this area, 72 was smoothly converted to 73 in the presence of PdCl2(PhCN)2 at room temperature." ... 

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