Phenyl ring, carbene-based, metallation

The preference for metallation of the carbene-based phenyl ring, over that of... 

The same authors then proceeded to synthesise the corresponding azolium salt based on the l,r-binaphthyl scaffold (see Figure 5.23) [79]. The same failure to synthesise either the free carbene or transition metal carbene complexes from it was estabUshed experimentally. Electronic destabilisation by a double annulation effect from the two phenyl (naphthyl) rings on the seven-membered azolium ring systan is indeed the most likely explanation. 

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