Reaction of (Acyloxy)alkyl α-Halides with Phenols: Effect of Nucleofugicity and Nucleophilicity on Product Distribution

Article abstract of DOI:10.1021/jo00169a035

The product distribution obtained from the reaction of (acyloxy)alkyl α-halides (1 or 5) with phenols was found to depend on the nucleophilicity of the phenol, the nucleofugicity of the leaving group, and the ability of the electrophile to stabilize a carbenium ion.More nucleophilic phenols tended to give more acylation while better leaving groups and more stable incipient carbenium ions in the electrophile tended to favor the formation of alkylated products.In addition, the reaction of methanol with 1a was found to give a mixture of acylated and alkylated products (40 : 60).Thus, a general trend for all the nucleophiles for which information is available suggests that better nucleophiles undergo relatively more acylation and that poorer nucleophiles undergo more alkylation.These results are suggested to be consistent with the observations of Westaway on the effect of leaving group nucleofugicity and nucleophilicity of the nucleophile on bond lengths in the S_N2 transition state.Facile rearrangements of acylated to alkylated products and of one alkylated product to another caused by the phenolate anion were also observed in the 3-phenoxy-1(3H)-isobenzofuranone-phenyl 2-formylbenzoate series.