@article {3034, title = {THE SYNTHESIS OF ANTHRAPHOS, A CONFORMATIONALLY RIGID, C-2-SYMMETRICAL DIPHOSPHINE AND THE X-RAY CRYSTAL-STRUCTURE OF [RH(COD)(ANTHRAPHOS)]BF4}, journal = {Tetrahedron Letters}, volume = {35}, number = {41}, year = {1994}, note = {ISI Document Delivery No.: PL496Times Cited: 7Cited Reference Count: 18}, month = {Oct}, pages = {7593-7596}, type = {Article}, abstract = {Anthraphos (trans-9,10-dihydro-9,10-ethanoanthracene-11,12-bis(diphenylphosphine) (3), a conformationally rigid, C-2-symmetric diphosphine, has been prepared in three steps, the key step being the Diets-Alder reaction between anthracene and ethyndiylbis(diphenylphosphine oxide). Resolution of anthraphos followed by formation of the [Rh(COD)(anthraphos)]BF4 complex afforded an optically active hydrogenation catalyst precursor whose crystal and molecular structure and absolute configuration were determined by single crystal X-ray diffractometry. Use of the (R,R)-(-) form of the catalyst precursor to hydrogenate (Z)-alpha-acetamidocinnamic acid gave (S)-(+)-N-acetylphenylalanine in 90\% enantiomeric excess.}, keywords = {ACID, ASYMMETRIC-SYNTHESIS, COMPLEXES, HYDROGENATION, LIGANDS, NORPHOS}, isbn = {0040-4039}, url = {://A1994PL49600027}, author = {Fu, T. Y. and Liu, Z. Q. and Scheffer, J. R. and Trotter, J.} }