Rhodium‐Catalysed Asymmetric Hydroformylation of Unsaturated Nitriles

Lambers‐Verstappen, Marielle M. H.; Vries, Johannes G. de

doi:10.1002/adsc.200390053

Cited by 53 publications

(24 citation statements)

References 34 publications

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“…Finally, the effect of reaction temperature on the selectivities was examined. As Table 1 (entries 11 and [15][16][17][18] shows, lower temperatures have a favorable effect on the selectivities. Thus, the best result to date was obtained when the reaction was carried out at 25°C, giving (S)-b-8 with 96:4 branchedto-linear ratio and 80% ee (entry 19).…”

Section: Resultsmentioning

confidence: 94%

“…However, the best result was in 76:24 branched-to-linear ratio and only 18% ee for b-8 (17). Also, the reaction rate was very low with only 31-45% conversion after 5 h by running the reactions at 60°C and 30 bars of CO͞H 2 (1:1) in toluene.…”

Section: Resultsmentioning

confidence: 95%

“…The best result for this process so far obtained to date was reported by de Vries and coworkers (17), giving 8 in 72:28 branched-to-linear ratio and 66% enantiomeric excess (ee) by using (R,S)-BINAPHOS as the chiral ligand. Accordingly, this process is useful but quite demanding, and an obvious need exists for the improvement in the regioselectivity and enantioselectivity for this process to be practical.…”

Section: Resultsmentioning

confidence: 98%

“…offers an attractive entry to (R)-2-methyl-4-aminobutanol, which is a key building block for TAK-637, a drug candidate for treatment of urinary continence (17). The best result for this process so far obtained to date was reported by de Vries and coworkers (17), giving 8 in 72:28 branched-to-linear ratio and 66% enantiomeric excess (ee) by using (R,S)-BINAPHOS as the chiral ligand.…”

Section: Resultsmentioning

confidence: 99%

“…1). These ligands have found a wide range of applications in metalcatalyzed asymmetric transformations such as hydrogenation (5,(8)(9)(10)), 1,4-additions of dialkylzinc (11,12) and boronic acids (13) to enones, hydrovinylation (14), hydrosilylation (15), intramolecular Heck reaction (16), hydroformylation (17), allylic alkylation (18,19), amination (20), and etherification (21).…”

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confidence: 99%

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New biphenol-based, fine-tunable monodentate phosphoramidite ligands for catalytic asymmetric transformations

Hua

Vassar

Choi

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

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Monodentate phosphoramidite ligands have been developed based on enantiopure 6,6-dimethylbiphenols with axial chirality. These chiral ligands are easy to prepare and flexible for modifications. The fine-tuning capability of these ligands plays a significant role in achieving high enantioselectivity in the asymmetric hydroformylation of allyl cyanide and the conjugate addition of diethylzinc to cycloalkenones. R ecently, chiral monodentate phosphorus ligands (phosphites, phosphoramidites, and phosphonites) have been attracting considerable interest for their use in catalytic asymmetric synthesis, because the chiral catalysts bearing these ligands have proven to be highly efficient in various asymmetric reactions. This is a previously univestigated wave in the design of chiral ligands, which makes a sharp contrast to almost three decades of predominance by C2 symmetrical bidentate phosphorus ligands for a variety of catalytic asymmetric transformations. This wave of designing simple and readily modifiable chiral structures, which are easy to synthesize, is fitting very well to the trendy and highly practical combinatorial approaches to the development of the most suitable chiral ligand for a particular catalytic asymmetric process of commercial value or academic interest. This approach is currently considered most practical rather than trying to develop a universal and almighty chiral ligand for different types of catalytic asymmetric transformations.Before the launch of our research program on the development of chiral monodentate phosphorus ligands based on enantiopure 2,2Ј-dihydroxy-6,6Ј-dimethylbiphenyls, by far, the most studied monodentate ligands were phosphites and phosphoramidites based on TADDOL (1) (1) BINOL (2) (2-4), a spirobiindanediol (3) (5), or an achiral biphenol (4) (6, 7) bearing a chiral or achiral secondary alcohol or amine (Fig. 1). These ligands have found a wide range of applications in metalcatalyzed asymmetric transformations such as hydrogenation (5, 8-10), 1,4-additions of dialkylzinc (11, 12) and boronic acids (13) to enones, hydrovinylation (14), hydrosilylation (15), intramolecular Heck reaction (16), hydroformylation (17), allylic alkylation (18, 19), amination (20), and etherification (21).We have been developing a previously uninvestigated class of chiral monodentate phosphite and phosphoramidite ligands, 5 and 6, from readily accessible enantiopure, axially chiral biphenyls ( Fig. 2) and have recently published the successful application of chiral monophosphite ligands 5 to the Rh(I)-catalyzed asymmetric hydrogenation of dimethyl itaconate (Fig. 2) (22).One of the salient and practical features of these chiral monophosphite ligands is the fine-tuning capability with modifiable substituents R 1 , R 2 , and R 3 in the formula 5. This fine-tuning capability of ligands 5 (phosphites) and 6 (phosphoramidites) is expected to play a crucial role in the application of these ligands to a variety of catalytic asymmetric reactions. In fact, we have demonstrated that the substituents (R 2 )...

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Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 95%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

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New biphenol-based, fine-tunable monodentate phosphoramidite ligands for catalytic asymmetric transformations

Hua

Vassar

Choi

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

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(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis-[diphenylphosphine](Xantphos)

Birkholz

Leeuwen

2008

Encyclopedia of Reagents for Organic Synthesis

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Chiral Ligands for Catalytic Asymmetric Synthesis

Athan

Lin

et al. 2013

Kirk-Othmer Encyclopedia of Chemical Technology

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This article focuses on the design and development of novel phosphite, phosphoramidite, and diphosphonite ligands with fine‐tuning capability and their successful applications to catalytic asymmetric synthesis. A library of chiral biphenol‐based phosphorus ligands have been designed, synthesized and applied to a wide range of transition metal‐catalyzed asymmetric catalytic reactions. These reactions include asymmetric hydrogenation, hydroformylation, conjugate addition, allylic amination, allylic alkylation, and allylic etherification. These reactions have also provided enantioselective routes to the syntheses of key intermediates in the total syntheses of bioactive natural products. The fine‐tuning capability of these ligands is proven critical in achieving excellent enantioselectivity and catalytic activity for specific reactions and processes.

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Rhodium‐Catalysed Asymmetric Hydroformylation of Unsaturated Nitriles

Cited by 53 publications

References 34 publications

New biphenol-based, fine-tunable monodentate phosphoramidite ligands for catalytic asymmetric transformations

New biphenol-based, fine-tunable monodentate phosphoramidite ligands for catalytic asymmetric transformations

(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis-[diphenylphosphine](Xantphos)

Chiral Ligands for Catalytic Asymmetric Synthesis

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