2-phenyl-2-(p-tosylamino)acetic acid, a versatile pro-ligand for organotin compounds

Herein we report the synthesis and structural study of ten new tin compounds derived from the polyfunctional and optically active pro-ligand: 2-phenyl-2-(p-tosylsuphonamino)acetic acid (1). Reactions of the sodium carboxylate of compound 1 with SnMe₂Cl₂; SnPh₂Cl₂, SnMe₃Cl, SnPh₃Cl and that of 1 with nBu₂SnO in benzene were investigated. Structures of the reaction products {chloro(dimethyl)tin [(S) 2-phenyl-2-(p-tolylamino)]acetate (2), trimethyltin [(S) 2-phenyl-2-(p-tolylamino)]acetate (3), triphenyltin (S) 2-phenyl-2-(4-methylphenylamino)acetate (4), dimethyltin bis-[2-phenyl-2-(p-tolylamino) acetate] (5), chlorophenyltin bis-[2-phenyl-2-(p-tolylamino)acetate] (6), diphenyltin bis-[2-phenyl-2-(p-tolylamino)acetate] (7) and aqua-dinbutyltin bis-[2-phenyl-2-(p-tolylamino) acetate] (8)} were determined by NMR and high resolution mass spectrometry. Two crystals from compound 3 (3a and 3b), one from aqua-diphenyltin bis-[2-phenyl-2-(p-tolylamino)acetate] (9) and one from dinbutyl-distannoxane tetra[2-phenyl-2-(p-tolylamino)acetate] (10) were analysed by X-ray diffraction. The new compounds are hypervalent; 2–4 are pentacoordinated, 5–7 are hexacoordinated whereas 8 and 9 are heptacoordinated. Theoretical study of compounds 2, 3, and the model compounds: dimethyltin bis-acetate, diphenyltin bis-acetate and their water complexes was performed by B3LYP/LANL2DZ base calculations, particularly O⋯O interaction through the space.