757961-32-3Relevant academic research and scientific papers
Oxidative addition of the C-O bond of amino acid esters to Rh(I) forming chelating acyl complexes
Grotjahn, Douglas B.,Joubran, Camil
, p. 3047 - 3056 (2008/10/09)
Esters of N-acylated amino acids and the sterically demanding phosphine 2-(di-ortho-tolylphosphino)phenol react within 1 h at room temperature with the Rh(I) centers of [Cl(μ-Cl)Rh(cyclooctene)2]2 to give products of oxidative addition of the ester carbonyl-O bond. The N-acyl carbonyl oxygen is bound to the Rh in these initial adducts, but is displaced upon addition of PMe3, PhPMe2, NH2NMe2, or the thioether function of a methionine derivative. Remarkably, both initial products from achiral amino acids and their ligand adducts are formed as single five-coordinate diastereomers in essentially quantitative yields. However, asymmetric induction by chiral amino acid derivatives of proline and phenylalanine on the stereochemistry at Rh was modest. Finally, the identities of infrared absorptions of acyl and amide groups in the complexes were established unequivocally by synthesis and spectroscopy of N-acetylglycine esters with a 13C label at either the ester or amide carbonyl group.
Controlled oxidative addition of amino acid esters to Rh(I)
Grotjahn, Douglas B.,Joubran, Camil,Combs, David
, p. 115 - 121 (2007/10/03)
The new sterically demanding phosphine 2-(di-o-tolylphosphino)phenol was prepared and used to create a series of esters with N-acylated amino acids. The phosphine-containing esters react within 30-60 min at room temperature with [(μ-Cl)Rh(cyclooctene)2]2 to give products of oxidative addition of the ester carbonyl-oxygen bond to the Rh center. The N-acyl carbonyl oxygen is bound to the Rh in these initial adducts, but is displaced upon addition of PMe3. Remarkably, both initial products and their PMe3 adducts are formed as single five-coordinate diastereomers in essentially quantitative yields.
