Chiral cyclopentadienyl catalysts. Part 3. Synthesis and reactions of (S)-1-(1-dimethylaminoethyl)-2-(2,3,4,5-tetramethylcyclopenta-1,3-dienyl)benzene; crystal structure of [Rh{η5-C5Me4C6H4CH(Me)NMe2}Cl2]
- 1 January 1994
- journal article
- Published by Royal Society of Chemistry (RSC) in J. Chem. Soc., Dalton Trans.
- No. 9,p. 1445-1451
- https://doi.org/10.1039/dt9940001445
Abstract
The synthesis of (S)-1-(1-dimethylaminoethyl)-2-(2,3,4,5-tetramethylcyclopenta-1,3-dienyl)benzene (HL) and its reactions with [Ru3(CO)12] and IrCl3·3H2O have been performed. Compound HL also reacts with RhCl3·3H2O to give a mixture of [Rh{η5-C5Me4C6H4CH(Me)NMe2}Cl2]1 and [{Rh[η5-C5Me4C6H4CH(Me)NMe2·HCl]Cl2}2]2. A single-crystal X-ray diffraction study of 1 was carried out: the compound crystallises in the orthorhombic, space group P212121(D2 4, no. 19) with a= 8.691 (6), b= 15.803(15), c= 13.840(10)Å and Z= 4; R= 0.0657. Interconversion between 1 and 2 can be effected readily using HCl or base respectively. Other aspects of the chemistry of 1 have been investigated including its conversion into [Rh{η5-C5Me4C6H4CH(Me)NMe2}(C2H4)2] in which rotation of the co-ordinated ethene molecules has been estimated by 1H NMR spectroscopy to have a free energy of activation (ΔG‡)= 67.2 kJ mol–1. In contrast to 1, the methylated derivative [Rh{η5-C5Me4C6H4CH(Me)NMe3 + BF4 –}Cl2] functions as a hydrogenation catalyst but with prochiral alkenes the optical yields were low (8% enantiomeric excess).Keywords
This publication has 31 references indexed in Scilit:
- Chiral phosphine ligands modified by crown ethers: an application to palladium-catalyzed asymmetric allylation of .beta.-diketonesJournal of the American Chemical Society, 1992
- Chiral cyclopentadienyl hydrogenation catalysts: crystal structures of [Rh(C5R4R★Cl2]2 (R = J, R★ = neomenthyl; R = Me, R★ = menthyl)Journal of Organometallic Chemistry, 1991
- The asymmetric aldol reaction of tosylmethyl isocyanide and aldehydes catalyzed by chiral silver(I) complexesThe Journal of Organic Chemistry, 1990
- Chiral cooperativity: the nature of the diastereoselective and enantioselective step in the gold(I)-catalyzed aldol reaction utilizing chiral ferrocenylamine ligandsThe Journal of Organic Chemistry, 1990
- Catalytic asymmetric hydrogenation of β-disubstituted α-phenylacrylic acids asymmetric synthesis of carboxylic acids containing two vicinal chiral carbon centersTetrahedron Letters, 1988
- Enantioselective Synthesis with Optically Active Transition-Metal CatalystsSynthesis, 1988
- The chemistry of tetraphenylcyclopentadienone complexes of ruthenium and rhodium: the X-ray crystal structure of [Ru{η5-C5Ph4OC(O)CH(OMe)Ph}(CO)2Cl]J. Chem. Soc., Dalton Trans., 1987
- Modification of optically active ferrocenylphosphine ligands for palladium-catalyzed asymmetric allylic alkylationTetrahedron Letters, 1986
- Kinetic resolution of racemic allyl acetates in asymmetric allylic alkylation catalysed by a chiral ferrocenylphosphine–palladium complexJournal of the Chemical Society, Chemical Communications, 1986
- Asymmetric Catalytic Hydrogenation: Mechanism and Origin of EnantioselectionPublished by Elsevier ,1985