[CpRu((R)-Binop-F)(H2O)][SbF6], a New Fluxional Chiral Lewis Acid Catalyst: Synthesis, Dynamic NMR, Asymmetric Catalysis, and Theoretical Studies
The C2-sym. electron-poor ligand (R)-BINOP-F (4; (R)-2,2'-[bis(pentafluorophenyl)phosphinoxy]-1,1'-binaphthalene) was prepd. by reaction of (R)-BINOL ((R)-1,1'-binaphthalene-2,2'-diol) with bromobis(pentafluorophenyl)phosphine in the presence of NEt3. The iodo complex [CpRu((R)-BINOP-F)(I)] ((R)-6) was obtained by substitution of two carbonyl ligands by (R)-4 in the in situ-prepd. [CpRu(CO)2H] complex followed by reaction with iodoform. Complex 6 was reacted with [Ag(SbF6)] in acetone to yield [CpRu((R)-BINOP-F)(acetone)][SbF6] ((R)-7). X-ray structures were obtained for both (R)-6 and (R)-7. The chiral 1-point binding Lewis acid [CpRu((R)-BINOP-F)][SbF6] derived from either (R)-7 or the corresponding aqua complex (R)-8 activates methacrolein and catalyzes the Diels-Alder reaction with cyclopentadiene to give the [4 + 2] cycloadduct with an exo/endo ratio of 99:1 and an ee of 92% of the exo product. Addn. occurs predominantly to the methacrolein Calpha-Re face. In soln., H2O in (R)-8 exchanges readily. Moreover, a 2nd exchange process renders the diastereotopic BINOP-F P atoms equiv. These processes were studied by the application of variable-temp. 1H, 31P, and 17O NMR spectroscopy, variable-pressure 31P and17O NMR spectroscopy, and, using a simpler model complex, d. functional theory (DFT) calcns. The results point to a dissociative mechanism of the aqua ligand and a pendular motion of the BINOP-F ligand. NMR expts. show an energy barrier of 50.7 kJ mol-1 (12.2 kcal mol-1) for the inversion of the pseudo-chirality at the Ru center. [on SciFinder (R)]
WOS:000220849900032
2004
126
15
4843
4853
CAN 141:7260
29-13
Organometallic and Organometalloidal Compounds
Department of Organic Chemistry and Department of Physical Chemistry and Laboratory of X-ray Crystallography,University of Geneva,Geneva,Switz.
Journal
written in English.
72204-08-1P ((S)-exo-2-Methylbicyclo[2.2.1]hept-5-ene-2-carboxaldehyde) Role: SPN (Synthetic preparation), PREP (Preparation) (asym. catalysis of Diels-Alder reaction of cyclopentadiene with methacrolein catalyzed by ruthenium cyclopentadienyl aqua and acetone bidentate-phosphinite complexes); 78-85-3 (Methacrolein) Role: RCT (Reactant), RACT (Reactant or reagent) (asym. catalysis of Diels-Alder reaction with cyclopentadiene catalyzed by ruthenium cyclopentadienyl aqua and acetone bidentate-phosphinite complexes); 542-92-7 (1,3-Cyclopentadiene) Role: RCT (Reactant), RACT (Reactant or reagent) (asym. catalysis of Diels-Alder reaction with methacrolein catalyzed by ruthenium cyclopentadienyl aqua and acetone bidentate-phosphinite complexes); 691365-15-8 Role: CPS (Chemical process), FMU (Formation, unclassified), PEP (Physical, engineering or chemical process), RCT (Reactant), FORM (Formation, nonpreparative), PROC (Process), RACT (Reactant or reagent) (intermediate in inversion of ruthenium cyclopentadienyl aqua bidentate-phosphinite model complex studied by d. functional theory); 691365-14-7 Role: CPS (Chemical process), PEP (Physical, engineering or chemical process), PRP (Properties), RCT (Reactant), PROC (Process), RACT (Reactant or reagent) (model complex for theor. study of inversion of ruthenium cyclopentadienyl aqua bidentate-phosphinite complex); 691365-08-9P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and conversion to iodo analog); 691365-07-8P; 691365-13-6P Role: PRP (Properties), SPN (Synthetic preparation), PREP (Preparation) (prepn. and crystal structure of); 694494-18-3P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and use in prepn. of ruthenium cyclopentadienyl hydrido bidentate-phosphinite complex); 691365-12-5P Role: CAT (Catalyst use), CPS (Chemical process), PEP (Physical, engineering or chemical process), PRP (Properties), SPN (Synthetic preparation), PREP (Preparation), PROC (Process), USES (Uses) (prepn., fluxionality, inversion barrier, exchange and asym. catalysis of Diels-Alder reaction by); 691365-06-7P Role: PRP (Properties), RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn., mol. structure and replacement of iodide by acetone in); 691365-10-3P Role: CAT (Catalyst use), PRP (Properties), RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), USES (Uses), RACT (Reactant or reagent) (prepn., mol. structure, aquation and asym. catalysis of Diels-Alder reaction by); 15243-33-1 (Dodecacarbonyltriruthenium) Role: RCT (Reactant), RACT (Reactant or reagent) (reaction with cyclopentadiene and bidentate-phosphinite ligand to give cyclopentadienyl bidentate-phosphinite hydrido complex); 13648-79-8 (Bis(pentafluorophenyl)phosphinous bromide) Role: RCT (Reactant), RACT (Reactant or reagent) (substitution reaction with binaphthalenediol); 18531-94-7 ((R)-BINOL) Role: RCT (Reactant), RACT (Reactant or reagent) (substitution reaction with diarylphosphinous bromide)
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