Threonine-Derived Phosphinite-Oxazoline Ligands for the Ir-Catalyzed Enantioselective Hydrogenation

Menges, Frederik; Pfaltz, Andreas

doi:10.1002/1615-4169(200201)344:1<40::aid-adsc40>3.0.co;2-7

Cited by 176 publications

(18 citation statements)

References 10 publications

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“…Since compound 4 , as obtained by us via enantioselective hydrogenation of (E)-2 using the ( R , R )‐configured catalyst, showed a positive optical rotatory power in chloroform ([α] D = + 18.3, c 0.5, CHCl 3 , ee = 87%), the ( S ) configuration was assigned to (+)‐ 4 . This configuration assignment is consistent with Menges and Pfaltz's report, in which the authors described the preparation of ( R )‐ 4 via ( S , S )‐Ir(ThrePHOX) complex catalyzed hydrogenation of (E)-2 . The ( S ) configuration was also proposed for (+)‐ 3 as obtained by us via enantioselective hydrogenation of (E)-1 using the same ( R , R )‐configured catalyst.…”

Section: Resultssupporting

confidence: 89%

“…As shown in Scheme , the retrosynthetic analysis led us to identify the asymmetric hydrogenation of (E)-1 as the key step to achieve, after simple modifications, the desired enantiomerically enriched RC-33 . Since the Ir(ThrePHOX) complex (Scheme ), developed by Menges and Pfaltz, showed high activity in the enantioselective hydrogenation of the β‐methylcinnamic ester (E)-2 (conversion% > 99%, ee of the ( R ) product = 92%), which is structurally related to (E)-1 , we decided to take advantage of this catalyst for our purposes.…”

Section: Resultsmentioning

confidence: 99%

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Studies on the Enantiomers of RC-33 as Neuroprotective Agents: Isolation, Configurational Assignment, and Preliminary Biological Profile

et al. 2013

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In this study we addressed the role of chirality in the biological activity of RC-33, recently studied by us in its racemic form. An asymmetric synthesis procedure was the first experiment, leading to the desired enantioenriched RC-33 but with an enantiomeric excess (ee) not good enough for supporting the in vitro investigation. An enantioselective high-performance liquid chromatography (HPLC) procedure was then successfully carried out, yielding both RC-33 enantiomers in amounts and optical purity suitable for the pharmacological study. The absolute configuration of pure enantiomers was easily assigned exploiting the asymmetric synthesis previously devised. As emerged in the preliminary in vitro biological investigation, (S)- and (R)-RC-33 possess a comparable affinity towards the σ1 receptor and a very a similar behavior in the calcium influx assay, resulting in an equally effective σ1 receptor agonist. Overall, the results obtained so far suggest that the interaction with the biological target is nonstereoselective and leads us to hypothesize that there is a lack of stereoselectivity in the biological activity of RC-33.

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Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Studies on the Enantiomers of RC-33 as Neuroprotective Agents: Isolation, Configurational Assignment, and Preliminary Biological Profile

et al. 2013

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“…Little stereoselectivity was obtained with most common heterogeneous catalysts, and many homogeneous catalysts were unreactive, for example, Pfaltz's catalyst. 18 Only after installation of the bulky TIPS group on the alcohol could hydrogenation on the opposite face of the hydroxymethyl group be effective with acceptable selectivity (see 9-12).…”

Section: Chemistrymentioning

confidence: 99%

Asymmetric Synthesis of Conformationally Constrained Fingolimod Analogues—Discovery of an Orally Active Sphingosine 1-Phosphate Receptor Type-1 Agonist and Receptor Type-3 Antagonist

Zhu

Snyder²,

Kharel³

et al. 2007

J. Med. Chem.

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Compound 1 (FTY720, Fingolimod) represents a new generation of immunosuppressant that modulates lymphocyte trafficking by interacting with the S1P 1 receptor. Compound 1 also provides a template molecule for studying the molecular biology of S1P receptors and related enzymes (kinases and phosphatases). In this study, two conformationally constrained analogues of 1 (3a and 3c) were asymmetrically synthesized in high optical purity. In vitro assessment documented that both analogues are Sphk2 substrates, their phosphorylated species are potent S1P 1 receptor agonists, and 3a-P is a potent S1P 3 antagonist. After oral administration in mice, both compounds evoked lymphopenia, but their duration of action differed markedly.

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“…Generally, metal complexed with different derivatives of chiral phosphino-imidazoline 1 ligand are highly versatile, readily accessible ligands for controlling the stereochemistry of metal-catalyzed reactions. Similarly, different derivatives of chiral oxazolines [2][3][4][5][6] are applied for transfer hydrogenation of olefin. Furthermore, similar work performed by Glorius et al where complete asymmetric hydrogenation of benzene (pyridine type) takes place.…”

Section: Introductionmentioning

confidence: 99%

Ru‐TsDPEN catalysts and derivatives in asymmetric transfer hydrogenation reactions

Mishra

Bhanage

2021

Chirality

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This review summarizes current developments, novel synthetic routes for Ruthenium tethered chiral catalyst, and its derivatives along with its application in asymmetric synthesis. The review also covers derivatization in tethering unit, modification in N-monofunctionalized ligand as well as ligation of other ligand with Ru metal in chiral catalyst. Apparently, the effect of a modified tethered catalyst in the enantioselective synthesis of chiral products as well as in synthetic chemistry is also discussed in detail.

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Threonine-Derived Phosphinite-Oxazoline Ligands for the Ir-Catalyzed Enantioselective Hydrogenation

Cited by 176 publications

References 10 publications

Studies on the Enantiomers of RC-33 as Neuroprotective Agents: Isolation, Configurational Assignment, and Preliminary Biological Profile

Studies on the Enantiomers of RC-33 as Neuroprotective Agents: Isolation, Configurational Assignment, and Preliminary Biological Profile

Asymmetric Synthesis of Conformationally Constrained Fingolimod Analogues—Discovery of an Orally Active Sphingosine 1-Phosphate Receptor Type-1 Agonist and Receptor Type-3 Antagonist

Ru‐TsDPEN catalysts and derivatives in asymmetric transfer hydrogenation reactions

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