P(i-BuNCH2CH2)3N: an efficient promoter for the nucleophilic aromatic substitution reaction of aryl fluorides with aryl TBDMS (or TMS) ethers.

[reaction: see text]. The nucleophilic aromatic substitution reaction between electron-deficient aryl fluorides and aryl TBDMS (or TMS) ethers has been shown to be efficiently promoted by proazaphosphatranes such as P(i-BuNCH(2)CH(2))(3)N (3). Excellent yields of diaryl ether products were obtained under unusually mild conditions.