The mechanism of the replacement of aluminum atoms in 1-ethyl-3-alkylalumolanes by boron atoms with boron halides.

In this study, the mechanism of the replacement reaction of an aluminum atom by a boron atom in the 1-ethyl-3-substituted alumolanes with boron halides is proposed. Theoretical and experimental justifications based on the DFT quantum chemical calculations of the energy parameters of possible reaction routes coupled with monitoring of the reaction between 1-ethyl-3-butylalumolane and BF·EtO, BCl and BBr using H, C, B and Al NMR spectroscopy are provided.

[NOMOGRAM AS A PROGNOSTIC TOOL FOR LYMPH NODE METASTASIS IN PATIENTS WITH BREAST CANCER].

It was retrospectively analyzed clinicopathological features of 529 breast cancer patients treated at the Ulyanovsk Oncology Center. Of 529 patients 235 (44.4%) had at least one positive axillary lymph node.