Facile and Selective Deallylation of Allyl Ethers Using Diphosphinidenecyclobutene-Coordinated Palladium Catalysts

(pi-Allyl)palladium triflate bearing a 1,2-bis(4-methoxyphenyl)-3,4-bis(2,4,6-tri-tert-butylphenylphosphinidene)cyclobutene ligand (DPCB-OMe), [Pd(eta(3)-C(3)H(5))(DPCB-OMe)]OTf, efficiently catalyzes deallylation of a variety of allyl ethers in aniline to give corresponding alcohols in high yields under mild conditions. The reactions can be performed in air without loss of a variety of functionalities including vinyl, alkynyl, hydroxy, acetoxy, silyloxy, and acetal groups. Allyl 2-allyloxybenzoate selectively undergoes deallylation of the allyloxy group to give allyl salicylate in quantitative yield.