Palladium(II)-mediated C-11-carbonylative coupling of diaryliodonium saltswith organostannanes - a new, mild and rapid synthesis of aryl [C-11]ketones

Palladium(II)-mediated [C-11]carbonylative coupling of diaryliodonium salts with aryltributylstannanes for 1 min in DME-water (4:1 v/v) at RT gives a new mild and rapid route to aryl [C-11]ketones. Substituted aryltributylsta nnanes couple with diphenyliodonium bromide to give substituted [C-11]benzo phenones in generally very high radiochemical yield (> 98%, decay-corrected ), while diphenyliodonium tosylates, bearing one or two substituents in one ring, couple with phenyltributylstannane to give a mixture of substituted (30-43%) and unsubstituted [C-11]benzophenone (47-66%). These reactions are highly attractive for introducing cyclotron-produced carbon-11 (t(1/2)=20. 4 min) into prospective radiotracers for application in medical imaging wit h positron emission tomography.