Application of tris(trimethylsilyl) phosphite as a convenient phosphorus nucleophile in the direct synthesis of tetrasubstituted α-aminophosphonic acids from ketimines

Abstract

The condensation of tris(trimethylsilyl) phosphite with various ketimines leads directly to tetrasubstituted a-aminophosphonic acids. The presented reaction proceeds readily at room temperature and provides labile silylated esters of tetrasubstituted a-aminophosphonic acids, as non-isolable reaction intermediates. Subsequent methanolysis of the latter provides the desired á-aminophosphonic acids bearing an fully substituted á-carbon in good overall yields as crystalline non-hygroscopic solids after simple recrystallization from a methanol-acetone mixture.nordstom.