Optically active transition-metal complexes, 8 - Transition-metal complexes of the optically active cyclopentadienyl ligand PinCp*: Crystal structureof (S-Re)-(eta(5)-PinCp*)Re(NO)(PPh3)[CONHCH(CH3)C10H7]
A. Salzer et al., Optically active transition-metal complexes, 8 - Transition-metal complexes of the optically active cyclopentadienyl ligand PinCp*: Crystal structureof (S-Re)-(eta(5)-PinCp*)Re(NO)(PPh3)[CONHCH(CH3)C10H7], EUR J INORG, (9), 1999, pp. 1497-1505
The synthesis of (eta(5)-PinCp*)Re(CO)(3) [PinCp* = tetramethyl(pinanyl)cyc
lopentadienyl] is described. Successive substitution of two CO ligands by N
O+ and PPh3 generates a 1:1 diastereomeric mixture of chiral-at-metal [(S-R
e)/(R-Re)- (PinCp*)Re(CO)(NO)(PPh3)]BF4. The diastereomers are converted wi
th sodium methoxide into the derivative "esters" (S-Re)/(R-Re)-(PinCP*)Re(C
OOCH3)(NO)(PPh3), and then with (+)-(R)-(1-naphthylethyl)amine to the "amid
es" (S-Re)/(R-Re)-(PinCp*)Re(NO)(PPh3)[CONHCH(CH3)C10H7] [(S-Re)/(R-Re) = 1
:1] Fractional crystallisation separates the (S-Re) isomer with an optical
purity of > 98%. The latter compound has been characterized by X-ray struct
ure analysis. By treating the (S-Re)-amide with CF3CO2H and NaBF4, (S-Re)-(
PinCp*)Re(CH3)(NO)(PPh3) can be generated. Protolysis of this compound with
HBF4/Et2O in CD2Cl2 at -78 degrees C leads to the solvent-stabilized compl
ex (S-Re)-[(PinCP*)Re(NO)(PPh3)(ClCD2Cl)]+BF4-. The thermal and configurati
onal stability of this chiral Lewis acid is investigated at various tempera
tures. The syntheses of [PinCp*RhCl2](2), PinCp*TiCl3 and PinCp*M(CO)(2)(NO
) (M = Mo, W) are also described. Starting with PinCp* M(CO)(2)(NO), the re
latively stable 16-VE complexes PinCp*MCl2(NO) and PinCp*W(CH2SiMe3)(2)(NO)
are synthesized.