Type of Publication: | Journal article |
Author: | Fischer, Helmut; Weißenbach, Kerstin; Karl, Christoph; Geyer, Armin |
Year of publication: | 1998 |
Published in: | European Journal of Inorganic Chemistry ; 1998 (1998), 3. - pp. 339-347. - ISSN 1434-1948. - eISSN 1099-0682 |
DOI (citable link): | https://dx.doi.org/10.1002/(SICI)1099-0682(199803)1998:3<339::AID-EJIC339>3.0.CO;2-9 |
Summary: |
Chiral carbene complexes [Cp(CO)2Mn=C(OR*)Ph] (4a−e) were prepared by reaction of [Cp(CO)2Mn=C(OAc)Ph] (2) with HOR* [HOR* = 1,2:3,4-di-O-isopropylidene-D-galactopyranose (3a), 2,3,4,6-tetra-O-acetyl-D-galactopyranose (3b), 2,3,4,6-tetra-O-acetyl-D-glucopyranose (3c), (S)- (3d) and (R)-1,2-O-isopropylideneglycerol (3e)]. The replacement of a CO ligand with PTol3 in 4a−e proceeded diastereoselectively to give [Cp(CO)(PTol3)Mn=C(OR*)Ph] (5a−e). The diastereoselectivity increased in the order a, b, c, d: de = 8% (5a), 33% (5b), 70% (5c), > 96% (5d). For (R)-5d the isomer with the (S) configuration at manganese (SMn) was formed predominantly. For (S)-5d, only (RMn,S)-5d was detected (de > 96%). Photolysis of (R)-4d in the presence of phosphites or phosphanes afforded (SMn)-[Cp(CO)(PR3)Mn=C(OR*)Ph] [PR3 = P(OPh)3 (8), P(OMe)3 (9), P(OMe)2Ph (10), P(OMe)Ph2 (11), PPh3 (12), P(C6H4Cl-p)3 (13)] with a de > 96%. Photolysis of (S)-4d in the presence of P(OMe)3 gave (RMn,S)-9. Complex (R)-14 [related to (R)-4d] was obtained from [Cp(CO)2Mn=C(OAc)Tol-p] and 3d. Replacement of CO by PR3 in (R)-14 gave (SMn,R)-[Cp(CO)(PR3)Mn=C(OR*)Tol-p] [R = Tol-p (15), OMe (16), C6H4Cl-p (17)] with a de > 96%. In solution, the PTol3-substituted complex 5d is configurationally stable whereas the P(OMe)3 complex 9 epimerizes slowly at room temperature in CH2Cl2, Et2O, and THF within about one week.
|
Subject (DDC): | 540 Chemistry |
Files | Size | Format | View |
---|---|---|---|
There are no files associated with this item. |
FISCHER, Helmut, Kerstin WEISSENBACH, Christoph KARL, Armin GEYER, 1998. Diastereoselective Substitution of PR3 for CO in Carbene(dicarbonyl)cyclopentadienyl Complexes of Manganese − Synthesis of (SMn)- and (RMn)-[Cp(CO)(PR3)Mn=C(OR*)R′] Complexes. In: European Journal of Inorganic Chemistry. 1998(3), pp. 339-347. ISSN 1434-1948. eISSN 1099-0682. Available under: doi: 10.1002/(SICI)1099-0682(199803)1998:3<339::AID-EJIC339>3.0.CO;2-9
@article{Fischer1998Diast-23048, title={Diastereoselective Substitution of PR3 for CO in Carbene(dicarbonyl)cyclopentadienyl Complexes of Manganese − Synthesis of (SMn)- and (RMn)-[Cp(CO)(PR3)Mn=C(OR*)R′] Complexes}, year={1998}, doi={10.1002/(SICI)1099-0682(199803)1998:3<339::AID-EJIC339>3.0.CO;2-9}, number={3}, volume={1998}, issn={1434-1948}, journal={European Journal of Inorganic Chemistry}, pages={339--347}, author={Fischer, Helmut and Weißenbach, Kerstin and Karl, Christoph and Geyer, Armin} }