ИСТИНА

This research is devoted to development of an enantioselective Suzuki cross-coupling reaction catalyzed by palladacycles. First, we have found that the CN-palladacycles offer an opportunity to perform Suzuki cross-coupling under extremely mild conditions (at –18 oC). After screening a broad set of chiral CPC's in the reaction of 2-methoxynaphthyl-1-iodide with naphthyl-1-boronic acid affording atropoisomeric 2-MeO-1,1'-binaphthyl, we have shown that maximum enantioselectivity (up to 53% ee) may be achieved using non-metallocenic [2.2]paracyclophane derived cyclopalladated imine dimer (Spl)-1a as catalyst at low temperature. The cyclopalladated catalyst was recovered in nearly quantitative yield (96 %) in the form of its myu-iodide analogue (Spl)-1b, whose structure was confirmed by spectral and X-ray diffraction study of its PPh3 derivative. Some experimental data provide an indirect evidence in support of the operation of two kinds of catalytic cycle, with dominant PdII/PdIV pathway in the aprotic solvent, while in alcohol classical PdII/Pd0 catalytic cycle becomes to be prevailing one.