Benzoic acid, 4- intramolecular reductive alkylation

More recently, Yu and coworkers [9] described the paUadium(II)-catalyzed ortho alkylation of simple benzoic acids with either 1,2-dichloroethane or dibro-momethane (Scheme 19.5). The use of the less activated 1-chloropentane was also feasible, but furnished only a 26% yield. This reaction was shown to proceed through initial intermolecular C-H alkylation followed by intramolecular Sj 2-cyclization to give the corresponding benzolactone. As mentioned, the C-H alkylation step was proposed to occur through oxidative addition-reductive elimination or o-bond metathesis. 

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