Reactivity of diacyloxyiodobenzenes toward trivalent phosphorus nucleophiles

Abstract

The reaction of diacyloxyiodobenzenes and tetravalent phosphorus nucleophiles was investigated. It was established that both H-phosphonates and secondary phosphine oxides react with diacetoxyiodobenzene in alcohols in the presence of sodium alcoholates yielding trialkyl phosphates and alkyl phosphinates respectively. For this transformation reactive intermediate 6 is proposed. In contrast to this, the treatment of diacetoxyiodobenzene with 3 equiv of sodium diisopropyl phosphite in THF produces diisopropyl 1-(diisopropoxyphosphinyl)ethylphosphonate with excellent yield. It was found that diacyloxyiodobenzene/PR3 system may serve as an acylating agent; the acylation process can proceed via carboxylic acid anhydride or acylphosphonium salt 17 depending on the protocol used. New very efficient method for synthesis of 2,4,6-trimethylbenzoic anhydride was developed. © 2003 Wiley Periodicals, Inc.