Methyl-functionalized chiral nonracemic monoindenyl complexes of rhodium, iridium, cobalt, and molybdenum.

Optically active complexes of Rh, Ir, Co, and Mo containing the chiral, menthyl-substituted indenyl ligands (-)-3-menthyl-4,7-dimethylindene, (-)-4,7-diisopropyl-3-menthylindene, and (+)-3-neomenthylindene are described. Metathetic reaction of the chiral main group metal salts of these indenyl systems with the appropriate starting materials of Rh and Ir yielded the complexes (-)-(pR)/(pS)-(1-menthyl-4,7-dimethylindenyl)Rh(COD) (7a/b), (pR)/(pS)-(1-menthyl-4, 7-diisopropylindenyl)Rh(COD) (8a/b), (+)-(pR)/(pS)-( 1-neomenthylindenyl)Rh(COD) (9a/b), (pR)/(pS)-(1-menthyl-4,7-dimethylindenyl (10a/b), (pR)/(pS)-(1-menthyl-4,7-dimethylindenyl)Rh(CO)(2) (11a/b), (pR)/(pS)-(1-menthyl-4,7-dimethylindenyl Rh(CO)(PPh3) (12a/b), (pR)/(pS)-( 1-menthyl-4, 7-dimethylindenyl)Rh(CO)(PPh2CH2CH2Si(OCH3)(3)) (13a/b), and (-)-(pR)/(pS)-(1-menthyl-4,7-dimethylindenyl)Ir(COD) (14a/b). CoCl2(dppe) reacts with (-)-(1-menthyl-4,7-dimethylindenyl)lithium (1), yielding (pR)/(pS)-(1-menthyl-4,7-dimethylindenyl)Co(dppe) (15a/b). Li[(pR)/(pS)-(1-menthyl-4,7-dimethylindenyl) Mo(CO)(3)] (16a/b), formed by transmetalation of Mo(CO)G, is oxidized by I-2, yielding (pR)/(pS)-(1-menthyl-4,7-dimethylindenyl)Mo(COC) (17a/b). Depending on the reaction conditions, all compounds were formed as mixtures of diastereomers with respect to the planar chirality of the indenyl ring system. The; diasteromeric excess varied between 9% and 71% de. Diastereomerically pure compounds were obtained after chromatography by dried alumina under nitrogen. The structures of 7a, 7b, 9a, 9b, and 14a were determined by single-crystal X-ray diffractometry.