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

Optically active complexes of Rh, Ir, Co, and Mo containing the chiral, men thyl-substituted indenyl ligands (-)-3-menthyl-4,7-dimethylindene, (-)-4,7- diisopropyl-3-menthylindene, and (+)-3-neomenthylindene are described. Meta thetic reaction of the chiral main group metal salts of these indenyl syste ms with the appropriate starting materials of Rh and Ir yielded the complex es (-)-(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-neoment hylindenyl)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-dimethyli ndenyl) Mo(CO)(3)] (16a/b), formed by transmetalation of Mo(CO)G, is oxidiz ed 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 mixtu res of diastereomers with respect to the planar chirality of the indenyl ri ng system. The; diasteromeric excess varied between 9% and 71% de. Diastere omerically pure compounds were obtained after chromatography by dried alumi na under nitrogen. The structures of 7a, 7b, 9a, 9b, and 14a were determine d by single-crystal X-ray diffractometry.