Approach to the stereoselective synthesis of melatonin receptor agonist Ramelteon via asymmetric hydrogenation

Yamano, Toru; Yamashita, Masayuki; Adachi, Mari; Tanaka, Mitsutaka; Matsumoto, Kiyoharu; Kawada, Mayumi; Uchikawa, Osamu; Fukatsu, K.; Ohkawa, Shigenori

doi:10.1016/j.tetasy.2005.11.005

Cited by 26 publications

(12 citation statements)

References 15 publications

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“…61 Currently, such reactions are carried out by means of 292 organometallic homogeneous catalysts, which depend on costly, usually phosphorus-based ligand 293 systems. 294…”

Section: Asymmetric Hydrogenation Of C=c Bonds 280 13mentioning

confidence: 99%

Aspects of Heterogeneous Enantioselective Catalysis by Metals

2011

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Publisher's copyright statement:This document is the Accepted Manuscript version of a Published Work that appeared in nal form in Langmuir, copyright c American Chemical Society after peer review and technical editing by the publisher. To access the nal edited and published work see http://pubs.acs.org/doi/abs/10.1021/la200009w. Additional information:Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Some aspects of metal-catalyzed heterogeneous enantioselective reactions are reviewed with specific 23 reference to four different systems where the phenomena that control enantioselection appear to be very 24 different. In the case of glucose electro-oxidation it is clear that any intrinsic chirality present at the 25 metal surface plays a vital role. With -keto hydrogenation, achiral surfaces modified by the adsorption 26 of chiral agents become effective enantioselective catalysts and formation of extended arrays of chiral 27 species appears not to be of importance: instead a 1:1 docking interaction controlled by hydrogen 28 bonding between the adsorbed chiral modifier and the prochiral reactant determines the outcome. 29Hydrogen bonding also plays a central role in -ketoester hydrogenation, but here fundamental studies 30indicate that the formation of ordered arrays involving the reactant and chiral ligand is of importance. 31Asymmetric C=C hydrogenation, though relatively little studied, has the potential for major impact in 32 synthetic organic chemistry both at the laboratory scale and in the manufacture of fine chemicals and 33 pharmaceuticals. The structural attributes that determine whether or not a given chiral ligand is effective 34 have been identified; the ability to form strong covalent bonds with the metal surface while also 35 resisting hydrogenation and displacement by the strongly-adsorbing reactant under reaction conditions 36 are essential necessary conditions. Beyond these, ligand rigidity in the vicinity of the chirality center 37 coupled with resistance to SAM formation are critically important factors whose absence results in 38 racemic chemistry.

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“…61 Currently, such reactions are carried out by means of 292 organometallic homogeneous catalysts, which depend on costly, usually phosphorus-based ligand 293 systems. 294…”

Section: Asymmetric Hydrogenation Of C=c Bonds 280 13mentioning

confidence: 99%

Aspects of Heterogeneous Enantioselective Catalysis by Metals

2011

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“…Continuing our efforts to develop efficient AH of challenging substrates, we are conviced that the additional coordination of a directing group to the metal and attractions between the ligand and substrate play a crucial role for both high reactivity and stereoselectivity [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]. Typically, catalyzed by a bisphosphine-Rh complex bearing a large bite angle (SKP [42,43] or SDP [44,45]) and assisted by a directing group (amide or ester) present in substrates, β-branched enamides or enol esters have been hydrogenated to produce β-chirogenic amines or alcohols in quantitative yields and with excellent enantioselectivities [23,33].…”

Section: Resultsmentioning

confidence: 99%

Asymmetric hydrogenation of γ‐branched allylamines for the efficient synthesis of γ‐chirogenic amines

et al. 2021

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The efficient construction of γ‐chirogenic amines has been realized via asymmetric hydrogenation of γ‐branched N‐phthaloyl allylamines by using a bisphosphine‐Rh catalyst bearing a large bite angle. The desired products possessing different γ‐substituents were obtained in quantitative yields and with excellent enantioselectivities (up to >99% ee). This protocol provides a practical method for the preparation of γ‐chirogenic amine derivatives such as the famous antidepressant drug Fluoxetine (up to 50000 S/C). The mechanistic calculations show an unusual P‐Rh‐P trans‐chelating pattern and a weak interaction‐promoted activation mode which are completely different from the traditional cis‐chelating pattern and coordination‐promoted activation mode in metal‐catalyzed hydrogenations. Key points Novel methodology of asymmetric hydrogenation was developed for efficient synthesis of γ‐chirogenic amines. New synthetic route was developed for the well‐known antidepressant drug Fluoxetine. Unusual mechanism information was found in the bidentate bisphosphine‐Rh‐catalyzed hydrogenation.

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“…The stereogenic centre can be set by an asymmetric hydrogenation with Ru-BINAP (Ru-10a) (Scheme 5). 55,56 The work-up was telescoped into a procedure that increased the ee of the product. With analogous, stepwise reactions, the reduction gave B92% ee.…”

Section: Rozeremmentioning

confidence: 99%

Asymmetric homogeneous hydrogenations at scale

Ager¹,

2012

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Asymmetric hydrogenations are increasingly being used to introduce stereogenic centres into products used in the life sciences industries. There are a number of potential pitfalls when moving from a laboratory reaction to a manufacturing process, not least of which is safety. Time-to-market pressure leads to short development times, which in the past could be a large barrier for the implementation of catalytic steps; now there are new ways to minimise this problem. The potential problems associated with impurities and other methods that can shut down the hydrogenation reactions are highlighted in this critical review (353 references).

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Approach to the stereoselective synthesis of melatonin receptor agonist Ramelteon via asymmetric hydrogenation

Cited by 26 publications

References 15 publications

Aspects of Heterogeneous Enantioselective Catalysis by Metals

Aspects of Heterogeneous Enantioselective Catalysis by Metals

Asymmetric hydrogenation of γ‐branched allylamines for the efficient synthesis of γ‐chirogenic amines

Asymmetric homogeneous hydrogenations at scale

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