Facile syntheses of building blocks for the construction of phosphotyrosine mimetics

Abstract

The copper-catalysed zinc phosphonate chemistry described by Yokomatsu and Shibuya can be used to enter the classical organometallic coupling repertoire via Stille and Suzuki–Miyaura couplings. 1,4-Diiodobenzene underwent coupling with the organozinc reagent derived from diethyl bromodifluoromethylphosphonate with copper(I) catalysis to afford diethyl (4-iodophenyl)difluoromethylphosphonate. Higher yielding couplings were run with (4-trifluoromethylsulfonyloxy)- and (4-nonafluorobutylsulfonyloxy)-iodobenzenes. The iodide and the triflate coupled under palladium-catalysed conditions with a range of stannanes and boronic acids in moderate to excellent yields. Shibuya–Yokomatsu couplings were also successful with more functionalised iodoarenes and heteroarenes presenting the important phosphate mimic on a range of scaffolds.