Enantioselective Synthesis of Planar Chiral [Cr(η6-Arene)(CO)3] complexes via nucleophilic addition/hydride abstraction. Preliminary communication

Non-racemic, planar chiral 1, 2-disubstituted [Cr(η⁶-arene)(CO)₃] complexes were obtained via external chiral ligand-controlled nucleophilic addition of alkyl-, vinyl-, and aryllithium reagents to monosubstituted complexes followed by an endo-hydride abstraction with trityl cation. The reactions with [Cr(CO)₃(η⁶-phenyloxazoline)], [Cr(CO)₃(η⁶-phenylmethaneimine)], and [Cr(CO)₃ (η⁶-phenylmethanenydrazone)] took place with complete ortho-selectivity and a high degree of enantioselectivity (up to 98% ee).     

Synthesen und Kristallstrukturen von [(t-Bu4Sb4)Fe(CO)4], [(t-Bu4Sb4)Mo(CO)5] und [(t-Bu3Sb4)Mo(η5-C5Me5)(CO)3]

Syntheses and Crystal Structures of [( t -Bu₄Sb₄)Fe(CO)₄], [( t -Bu₄Sb₄)Mo(CO)₅], and [( t -Bu₃Sb₄)Mo(η⁵-C₅Me₅)(CO)₃] t-Bu₄Sb₄ reacts with Fe₂(CO)₉ to form [(t-Bu₄Sb₄)Fe(CO)₄] ( 1 ). [(t-Bu₄Sb₄)Mo(CO)₅] ( 2 ) is formed from (thf)Mo(CO)₅ and t-Bu₄Sb₄. [(t-Bu₃Sb₄)Mo(η⁵-C₅Me₅)(CO)₃] ( 3 ) is a product of the reaction of t-Bu₄Sb₄ with [(η⁵-C₅Me₅)Mo(CO)₃]₂. The crystal structures of 1–3 are reported.     

Synthesis,Characterization and Reactivity of the Tricarbonyl(formylcycloheptatrienyl)iron‐Anion [(η3‐C7H6CHO)Fe(CO)3]−

Deprotonation of the readily available organometallic aldehyde derivative [(η⁴‐C₇H₇CHO)Fe(CO)₃] ( 2 ) with NaN(SiMe₃)₂ in benzene solution at ambient temperature afforded the anionic formylcycloheptatrienyl complex Na[(η³‐C₇H₆CHO)Fe(CO)₃] ( 3 ). The anion is fluxional in solution and displays a unique ambident reactivity towards electrophiles (MeI, Me₃SiCl). New substituted [(η⁴‐RC₇H₆CHO)Fe(CO)₃] and [(η⁴‐heptafulvene)Fe(CO)₃] complexes have been identified as the products. Treatment of 3 with 0.5 equivalents of dimeric [(COD)RhCl]₂ (COD = 1,5‐cyclooctadiene) afforded the functionalized Fe‐Rh cycloheptatrienyl complex [(μ‐C₇H₆CHO)(CO)₃FeRh(COD)] ( 7 ) in up to 86 % yield. Carbonylation of 7 under an atmosphere of CO led to facile conversion to the heterobimetallic pentacarbonyl derivative [(μ‐C₇H₆CHO)(CO)₃FeRh(CO)₂] ( 8 ), which is also accessible in lower yield from the direct reaction of 3 with [Rh(CO)₂Cl]₂.     

Die Molekül- und Kristallstrukturen von (CO)4 W(μ-S-t-C4H9)2W(CO)4, η7-C7H7W(μ-SC6H4CH3)3W(CO)3 und η7-C7H7W(μ-S-n-C4H9)3W(CO)(μ-S-n-C4H9)2W(CO)4

Molecular and Crystal Structures of (CO)₄W(μ-S-t-C₄H₉)₂W(CO)₄, η⁷-C₇H₇W(μ-SC₆H₄CH₃)₃W(CO)₃ and η⁷-C₇H₇W(μ-S-n-C₄H₉)₃W(CO)(μ-S-n-C₄H₉)₂W(CO)₄ The molecular structures of the two binuclear complexes (CO)₄W(μ-S-t-C₄H₉)₂W(CO)₄ and η⁷-C₇H₇W(μ-SC₆H₄CH₃)₃W(CO)₃ and of the tungsten cluster η⁷-C₇H₇W(μ-S-n-C₄H₉)₃W(CO)-(μ-S-n-C₄H₉)₂W(CO)₄ respectively are described. In the nonlinear trinuclear cluster the central tungsten atom is connected to the two tungsten atoms by two and three μ-S-n-C₄H₉ bridges respectively and additionally by one W? W bond each. The coordination sphere of the W atoms is completed by a η⁷-C₇H₇ ring and four CO groups respectively; the central tungsten carries an additional CO group.     

Addition des O'Donnell Reagenzes [Ph2C=NCHCO2Me]– an π-koordinierte,ungesättigte Kohlenwasserstoffe in [(C6H7)Fe(CO)3]+, [(C7H9)Fe(CO)3]+, [(C7H7)M(CO)3]+ (M = Cr,Mo) und [(C2H4)Re(CO)5]+. α-Aminosäuren mit metallorganischen Seitenketten

Metal Complexes of Biologically Important Ligands. CXVII [1] Addition of the O'Donnell Reagent [Ph₂C=NCHCO₂Me]^– to Coordinated, Unsaturated Hydrocarbons of [(C₆H₇)Fe(CO)₃]⁺, [C₇H₉Fe(CO)₃]⁺, [(C₇H₇)M(CO)₃]⁺ (M = Cr, Mo), and [(C₂H₄)Re(CO)₅]⁺. α-Amino Acids with Organometallic Side Chains The addition of [Ph₂C=NCHCO₂Me]^– to [(C₆H₇)Fe(CO)₃]⁺, [(C₇H₉)Fe(CO)₃]⁺, [(C₇H₇)M(CO)₃]⁺ (M = Cr, Mo) and [(C₂H₄)Re(CO)₅]⁺ gives derivatives of α-amino acids with organometallic side chains. The structure of [(η⁴-C₆H₇)CH(N=CPh₂)CO₂Me]Fe(CO)₃ was determined by X-ray diffraction. From the adduct of [Ph₂C=NCHCO₂Me]^– and [(C₇H₇)Mo(CO)₃]⁺ the Schiff base of a new unnatural α-amino acid, Ph₂C=NCH(C₇H₇)CO₂Me, was obtained.