ИСТИНА

In the last twenty years, catalytic systems based on 3d metals have been actively developed as alternatives to noble metals derivatives. In particular, carbonyl-containing manganese(I) complexes have proven themselves to be good catalysts for (de)hydrogenation and hydrosilylation reactions of organic substrates.1 Generally, non-covalent adducts of metal hydrides adducts with substrates represent the key intermediates in these catalytic transformations. Our previous work was devoted to the study of the reactivity and kinetic hydricity (ΔG≠) of tricarbonyl manganese(I) complexes with phosphite, phosphine and phosphine-carbene ligands.2, 3 In this report we present recent results on the reactivity of dicarbonyl manganese complexes (1, 2) with pincer-type and tripodal phosphine ligands (Figure 1) in hydride ion transfer processes to Lewis acid using IR (νCO) and NMR (1H, 31P) spectroscopic methods in a wide temperature range (160-298 K). This investigation allowed to identify reaction mechanism, determine structure of the reaction intermediates and experimentally estimate the values of the kinetic hydricity, which is higher for tripodal structure 2. These data were in agreement with catalytic activity of triphosphine manganese(I) complexes in the hydrosilylation of benzyl benzoate with phenylsilane.