Hypercoordinated diorganoantimony(III) compounds of types [2‐(Me2NCH2)C6H4]2SbL and [PhCH2N(CH2C6H4)2]SbL (L = Cl, ONO2, OSO2CF3). Synthesis, structure and catalytic behaviour in the Henry reaction

The compounds [2‐(Me2NCH2)C6H4]2SbL (L = ONO2 (2), OSO2CF3 (3)) and [PhCH2N(CH2C6H4)2]SbL (L = ONO2 (5), OSO2CF3 (6)) were prepared by reacting [2‐(Me2NCH2)C6H4]2SbCl (1) and [PhCH2N(CH2C6H4)2]SbCl (4), respectively, with the appropriate silver(I) salt in a 1:1 molar ratio. The new species 2–6 were structurally characterized in solution using multinuclear NMR and in the solid state using infrared spectroscopy. The solid‐state structures for compounds 2, 4 and 6, as well as for the hydrolysis ionic product [{2‐(Me2N+HCH2)C6H4}{2‐(Me2NCH2)C6H4}SbOH][CF3SO3]− (3h) were determined using single‐crystal X‐ray diffraction. Medium to strong intramolecular N→ Sb interactions were observed in all these four compounds, thus resulting in hypercoordinated organoantimony(III) species 14‐Sb‐6 in 2 and 10‐Sb‐4 in the cation of 3h and in 4 and 6. Compounds 1–6 and the starting amines PhCH2NMe2 and PhCH2N(CH2C6H4Br‐2)2 were investigated as catalysts in the Henry (nitroaldol) addition of nitromethane to benzaldehyde. The activity of compounds 1–6 resulted as an effect of the cooperation of the positively charged antimony with the negatively charged nitrogen. [ABSTRACT FROM AUTHOR]