Diethyl α-aminophosphonate containing lubricating additives synthesized from (3-aminophenyl)boronic acid pinacol ester

In this paper, (3-aminophenyl)boronic acid pinacol ester was employed as a raw material to react with different aromatic aldehydes. Then diethyl phosphite was introduced to produce the addition reaction of carbon nitrogen double bond to prepare four diethyl α-aminophosphonate derivatives, which were diethyl[phenyl({[3-(tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]amino})methyl]phosphonate (BNP 1 ), diethyl[(4-methoxyphenyl)({[3-(tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]amino})methyl]phosphonate (BNP 2 ), diethyl [(4-nitrophenyl)({[3-(tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]amino})methyl]phosphonate (BNP 3 ), and diethyl[(4-methylphenyl)({[3-(tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]amino})methyl]phosphonate (BNP 4 ). The prepared compounds were characterized by 1 H and 13 C NMR, MS, FT-IR and PL (Photoluminescence Spectroscopy). Four derivatives perform high thermal stability. In addition, it exhibits good friction properties for rapeseed oil (RSO) at low concentrations. Compared with BNP 1 , BNP 2 and BNP 4 , BNP 3 exhibits best on friction-reducing and anti-wear performances attributed to the strong electron withdrawing ability of the nitro group in BNP 3 , which is also reflected in the solid-state fluorescence. Therefore, the four diethyl α-aminophosphonate derivatives have potential industrial applications as lubricant additives .