A. Togni, Claude Breutel, M.C.F. Soares
Jul 1, 1994
Citations
0
Influential Citations
43
Citations
Journal
Inorganica Chimica Acta
Abstract
Abstract The reaction of ( R )-1-[( S )-(diphenylphosphino)ferrocenyl]ethyl acetate ( 1 ) or N,N -dimethyl-( R )-1-[( S )-(diphenylphosphino)ferrocenyl]ethylamine ( 2a ) with secondary phosphines in acetic acid leads to the diphosphines 5 in moderate to good yields. Two of these ligands, ( R )=1[( S )-(diphenylphosphino)ferrocenyl]ethyl-dicyclohexylphosphine ( 5a ) and ( R P , R )-1[( S )-(diphenylphosphino)ferrocenyl]ethyl-phenyl-(2-methoxyphenyl)phosphine ( 5g ), as well as the complexes [Rh( 5a )(NBD)]BF 4 ·2CH 2 Cl 2 ( 9 ), [Pd(η 3 -C 3 H 5 ) ( 5a )]OTf ( 10 ) and [PtCl 2 ( 5a )] ( 11 ), have been characterized by X-ray diffraction. Crystals of 5a, 9, 10 and 11 are orthorhombic, space group P 2 1 2 1 2 1 , with four molecules in the unit cell. 5a : a =10.772(1), b =15.278(1), c =21.069(2) A; 9 : a =18.166(2), b =17.540(2), c =14.564(1); 10 : a =10.995(4), b =14.021(8), c =25.410(11) A; 11 : a =15.077(14), b =15.122(16), c =16.188(11) A. The stereogenic-at-phosphorus derivative 5g crystallizes in the monoclinic system, space group P 2 1 , with two pairs of symmetry independent molecules per the unit cell with a =7.896(1), b =25.667(2), c =15.654(1) A and β=92.39(1)°. Very similar conformations of the chelate rings in the complexes 9–11 are observed, this being indicative of the relative rigidity of the ligand 5a .