Asymmetric Hydrogenations With Rhodium Chiral Phosphine Catalysts

Koenig, Karl E.; Sabacky, M. J.; Bachman, Gerald L.; Christopfel, W. C.; Bamstorff, H. D.; Friedman, Robert; Knowles, William S.; Stults, B. Ray; Vineyard, B. D.; Weinkauff, D. J.

doi:10.1111/j.1749-6632.1980.tb53625.x

Cited by 48 publications

(12 citation statements)

References 5 publications

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“…The stereochemical pathway in the Miyaura-Hayashi reaction catalyzed by BINAP, as well as in the overwhelming majority of metal-mediated asymmetric reactions, is based on the assumption that the substrates approach the metal so as to minimize steric interactions with the protruding R groups of the chiral ligand structure. [20,43] However, the half view of our rhodium disulfoxide complexes shown above (see partial views in Figure 4) clearly indicates that our system is devoid of any significant steric crowding around the metal center. Indeed, the aryl groups on the sulfoxide units are oriented away from the metal center and parallel to the atropisomeric backbone, leaving the oxygen atoms of the sulfoxide moieties as the sole entities approaching the metal center.…”

Section: Wwwchemeurjorgmentioning

confidence: 82%

C₂‐Symmetric Chiral Disulfoxide Ligands in Rhodium‐Catalyzed 1,4‐Addition: From Ligand Synthesis to the Enantioselection Pathway

Mariz

Poater

Gatti

et al. 2010

Chemistry A European J

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A family of chiral C(2)-symmetric disulfoxide ligands possessing biaryl atropisomeric backbones has been synthesized by using the Andersen methodology. Complete characterization includes X-ray crystallographic studies of all ligands and some of their rhodium complexes. Their synthesis, optical purity, electronic properties, and catalytic behavior in the prototypical rhodium-catalyzed 1,4-addition of phenylboronic acid to 2-cyclohexen-1-one are presented through an in depth study of this ligand class. Density functional theory calculations on the step of the catalytic cycle that determines the enantioselectivity are presented and reinforce the first hypothetical explanations for the high levels of asymmetric induction observed.

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Section: Wwwchemeurjorgmentioning

confidence: 82%

C₂‐Symmetric Chiral Disulfoxide Ligands in Rhodium‐Catalyzed 1,4‐Addition: From Ligand Synthesis to the Enantioselection Pathway

Mariz

Poater

Gatti

et al. 2010

Chemistry A European J

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“…Furthermore, a mechanistic study of asymmetric hydrogenation of methyl ( Z )-α-acetamidocinnamate catalyzed by BisP*-Rh complex revealed some new aspects of the reaction pathway , In the usual explanations of the stereoselection mechanism in the catalytic asymmetric hydrogenations the carboxy group of a dehydroamino acid is regarded as an important stereoregulating factor. ,− In the structure of an enamide the carboxy group is absent, but the nature of the substituent at the α-position can be varied without losing the high degree of enantioselectivity. Therefore, a mechanistic study of catalytic asymmetric hydrogenation of enamides can provide new details of the structure of the intermediates and the mechanism of stereoselection in the Rh-catalyzed hydrogenations.…”

Section: Introductionmentioning

confidence: 99%

Asymmetric Hydrogenation of Enamides with Rh-BisP* and Rh-MiniPHOS Catalysts. Scope, Limitations, and Mechanism

et al. 2001

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The asymmetric hydrogenation of aryl- and alkyl-substituted enamides catalyzed by Rh-BisP complex affords optically active amides with very high ee values. The Rh-MiniPHOS catalyst gives somewhat less satisfactory results. Hydrogenation of the aryl-substituted enamides with (S,S)-BisP-Rh catalyst gives R-amides, whereas the t-Bu- and 1-adamantyl-substituted enamides give S-products with 99% ee. Reaction of [Rh(BisP)(CD(3)OD)(2)]BF(4) (11) with CH(2)=C(C(6)H(5))NHCOCH(3) (5) gives two diastereomers of the catalyst-substrate complex (12a,b), which interconvert reversibly by both intra- and intermolecular pathways as shown by EXSY data. Only one isomer in equilibrium with solvate complex 11 was detected for each of the catalyst-substrate complexes 17 and 18 obtained from CH(2)=C(t-Bu)NHCOCH(3) (6) or CH(2)=C(1-adamantyl)NHCOCH(3) (7). Hydrogenation of these equilibrium mixtures at -100 degrees C gave monohydride intermediates 19 and 20, respectively. In these monohydrides the Rh atom is bound to the beta-carbon. A new effect of the significant decrease of ee was found for the asymmetric hydrogenation of CH(2)=C(C(6)H(4)OCH(3)-o)NHCOCH(3) (21), when H(2) was substituted for HD or D(2).

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“…Excellent yields (up to 99% yield) and enantioselectivities (up to 98% ee) were observed in Rh-catalyzed stereoselective 1,4-additions of differently substituted arylboronic acids 2 to electron-deficient olefins, such as a,b-unsaturated carbonyl compounds 1a-c,g,z under mild reaction conditions to provide 159a-q (Table 46). 151 The stereochemical result of these Rh-complex catalyzed 1,4-additions can be explained as illustrated in Fig. 8.…”

Section: Methodsmentioning

confidence: 98%

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

Heravi

Dehghani

Zadsirjan

2016

Tetrahedron: Asymmetry

109

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Rh-catalyzed asymmetric 1,4-addition reactions to a,b-unsaturated carbonyl and related compounds: an update Available online xxxx Dedicated to my son, OMID on the occasion of his 35th birthday. a b s t r a c tThe Rh-catalyzed asymmetric 1,4-addition of organometallic reagents to an appropriate receptor has been a growing area of research over the last decade. The receptors for such a 1,4-addition reaction are chiefly a,b-unsaturated ketones, esters, amides, enones, nitroalkenes, and occasionally phosphonates etc. This reaction in the presence of chiral rhodium complexes introduce the aryl and alkenyl groups at the b-position of the above electron poor olefins, enantioselectively. Chiral Rh complexes similar to other transition metals can be added to some electron poor olefins, in turn making them viable to attack by various organometallic reagents for highly enantioselective C-C bond formation. The Rh-catalyzed asymmetric 1,4-addition of organometallic reagents to electron poor olefins has been reviewed in 2003. Due to the importance of the asymmetric C-C bond formation via 1,4-conjugate addition reactions and the number of such reactions catalyzed by Rh-complexes, in this review we highlight the recent advances in Rh-complex asymmetric catalyzed 1,4-addition reactions since 2003.

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Asymmetric Hydrogenations With Rhodium Chiral Phosphine Catalysts

Cited by 48 publications

References 5 publications

C₂‐Symmetric Chiral Disulfoxide Ligands in Rhodium‐Catalyzed 1,4‐Addition: From Ligand Synthesis to the Enantioselection Pathway

C₂‐Symmetric Chiral Disulfoxide Ligands in Rhodium‐Catalyzed 1,4‐Addition: From Ligand Synthesis to the Enantioselection Pathway

Asymmetric Hydrogenation of Enamides with Rh-BisP* and Rh-MiniPHOS Catalysts. Scope, Limitations, and Mechanism

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

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Asymmetric Hydrogenations With Rhodium Chiral Phosphine Catalysts

Cited by 48 publications

References 5 publications

C2‐Symmetric Chiral Disulfoxide Ligands in Rhodium‐Catalyzed 1,4‐Addition: From Ligand Synthesis to the Enantioselection Pathway

C2‐Symmetric Chiral Disulfoxide Ligands in Rhodium‐Catalyzed 1,4‐Addition: From Ligand Synthesis to the Enantioselection Pathway

Asymmetric Hydrogenation of Enamides with Rh-BisP* and Rh-MiniPHOS Catalysts. Scope, Limitations, and Mechanism

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

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C₂‐Symmetric Chiral Disulfoxide Ligands in Rhodium‐Catalyzed 1,4‐Addition: From Ligand Synthesis to the Enantioselection Pathway

C₂‐Symmetric Chiral Disulfoxide Ligands in Rhodium‐Catalyzed 1,4‐Addition: From Ligand Synthesis to the Enantioselection Pathway