A. Karasik, I. O. Georgiev, E. Musina
Dec 15, 2001
Citations
1
Influential Citations
43
Citations
Journal
Polyhedron
Abstract
Acyclic and cyclic amino acid derivatives of 2-phosphinophenols have been synthesised by reaction of primary phosphinophenols (4-R-2-H2PC6H3OH; R=H, Me, OMe) 1a–c with formaldehyde and amino acids (o- and p-aminobenzoic acid, l-lysine) via in situ formed hydroxymethyl species 2a–c. Condensation reactions with glycine did not afford defined products except when the methoxymethyl and tetrahydropyranyl ethers of 1d,e were used instead of the hydroxy compounds. o-Aminobenzoic acid gives rise to linear bis(o-carboxyphenylaminomethyl)phosphines 3a–e. p-Aminobenzoic acid, dependent on the molar ratio, affords bis(p-carboxyphenylaminomethyl)phosphines 4a,d as well as eight-membered heterocyclic 1,5,3,7-diazadiphosphacyclooctanes 5a–e. The aliphatic amino acids glycine and l-lysine form six-membered heterocyclic 1,3,5-diazaphosphorinanes 6d and 7a–e, respectively, in presence of excess formaldehyde. l-lysine differs from glycine by reaction at the terminal amino group. The structures of the compounds have been elucidated by multinuclear NMR spectroscopy. The salts of the phosphino amino acids are soluble in water. Water solubility increases with the number of hydrophilic groups, i.e. free phenols are more soluble than their ethers. Ligand concentrations in water from 0.1 to 1 M were observed.