Asymmetric Hydrogenation of α‐(Acetylamino)cinnamic Acid with a Novel Rhodium Complex; the Design of an Optimal Ligand

Chiral pyrrolidine SalenMn(III) complexes with an anchored functional group at the N aza -substituent in the pyrrolidine backbone were synthesized, and used as catalysts for asymmetric epoxidation of substituted chromenes. The complex 1 with an anchored imidazole as acceptor could effectively catalyze epoxidation of substituted chromenes in the absence of expensive additive 4-phenyl pyridine N-oxide (PPNO) by the coordination of the anchored organic base to the central manganese ion. Complexes 2 and 3 with a quaternary ammonium salt unit at the N aza -substituent in the pyrrolidine backbone displayed higher activities than Jacobsen catalyst and the analogous complex 4 without anchored functional group in the aforementioned reaction. Copyright

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“…The experimental procedure for the synthesis of L 4 was carried out as described previously [22,23] with minor modification. Yield 58%.…”

Section: Synthesis Of Salen Ligand Lmentioning

confidence: 99%

Asymmetric epoxidation of chromenes catalyzed by chiral pyrrolidine SalenMn(III) complexes with an anchored functional group

Zhang

Wang

Jia

et al. 2008

Applied Organom Chemis

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“…For the preparation of the title compound, see: Nagel et al (1984); Inoguchi et al (1990). The title compound is used in the preparation of the chiral phosphine ligand DEGphos, (+)-(3R,4R)-N-benzyl-3,4-bis(diphenylphosphino)pyrrolidine, (Nagel et al, 1984), an efficient ligand for Rh-catalysed asymmetric hydrogenation (Tang & Zhang, 2003). Table 1 Hydrogen-bond geometry (Å , ).…”

Section: Related Literaturementioning

confidence: 99%

“…E66, o928 The title compound (+)-(3S,4S)-1-benzylpyrrolidine-3,4-diol was obtained from L-tartaric acid by condensation with benzylamine followed by reduction with NaBH 4 -BF 3 .Et 2 O. This is used for preparation of the chiral phosphine ligand DEGphos ((+)-(3R,4R)-N-benzyl-3,4-bis(diphenylphosphino)pyrrolidine, (Nagel et al, 1984), an efficient ligand for Rhcatalyzed asymmetric hydrogenations (Tang & Zhang, 2003).…”

Section: Sup-1mentioning

confidence: 99%

(3S,4S)-1-Benzylpyrrolidine-3,4-diol

Sun

Wang

2010

Acta Cryst E

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“…[13] PyrPhos was a gift, prepared following a procedure described in literature. [3] NADP was obtained from J¸lich Fine Chemicals. All other chemicals were obtained from Sigma-Aldrich and were of the best quality available and used without further purification.…”

Section: Experimental Section Generalmentioning

confidence: 99%

“…The feasibility of the application of volume-aeration to hydrogenation was investigated for chemical and enzymatic catalysis. We chose the homogeneous hydrogenation catalyst PyrPhos [3] as the chemical representative, whereas the hydrogenase I from the hyperthermophilic archeon Pyrococcus furiosus (PfH) illustrates the enzymatic approach.[4] Both catalysts activate hydrogen; the PyrPhos system for the enantioselective reduction of activated double bonds, whereas the PfH is capable of heterolytic cleavage of hydrogen and regioselective 1,4-hydride addition to the oxidized form of the phosphorylated nicotinamide cofactor: NADP (Scheme 1). In the case of the enzymatic approach the macromolecular catalyst was recycled by means of ultrafiltration.…”

mentioning

confidence: 99%

Membrane Aerated Hydrogenation: Enzymatic and Chemical Homogeneous Catalysis

Greiner

Müller

Ban³

et al. 2003

Adv Synth Catal

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Among the most successful systems for homogeneous catalysis, hydrogenation catalysts capable of activating molecular hydrogen, take outstanding roles in research laboratories and in industry. To open up the field of continuous catalytic hydrogenations a novel membrane reactor concept was developed and successfully applied for hydrogenations with dihydrogen both for chemical and for enzymatic catalysis. The hydrogenase I of the archaeon Pyrococcus furiosus was utilized for the continuous hydrogenation of NADP to NADPH with recycling of the enzyme by means of ultrafiltration. The well known PyrPhos-Rh system was used for the enantioselective synthesis of an amino acid derivative by hydrogenation.Keywords: asymmetric catalysis; catalyst immobilization; cofactors; enzyme catalysis; homogeneous catalysis; hydrogenation; membranes; reduction Here we report our most recent efforts to extend the range of feasible reactions in the membrane reactor [1] to hydrogenation with dihydrogen as reducing agent. The direct usage of hydrogen has several advantages over the usage of hydrogen transfer agents like 2-propanol [2] since it constitutes a cheaper and more powerful means of reduction that can be used in large excess and be easily removed, thus not hampering downstream processing.For this approach a novel reactor concept was developed for the continuous dosage of gaseous reactants via a dense polymer membrane. The feasibility of the application of volume-aeration to hydrogenation was investigated for chemical and enzymatic catalysis. We chose the homogeneous hydrogenation catalyst PyrPhos [3] as the chemical representative, whereas the hydrogenase I from the hyperthermophilic archeon Pyrococcus furiosus (PfH) illustrates the enzymatic approach.[4] Both catalysts activate hydrogen; the PyrPhos system for the enantioselective reduction of activated double bonds, whereas the PfH is capable of heterolytic cleavage of hydrogen and regioselective 1,4-hydride addition to the oxidized form of the phosphorylated nicotinamide cofactor: NADP (Scheme 1). In the case of the enzymatic approach the macromolecular catalyst was recycled by means of ultrafiltration.Reactor Set-Up: For continuous dosage of dihydrogen in a continuously operated membrane reactor a new setup was developed. The general scheme is shown in Figure 1. The delivery of gaseous reactants can be achieved by pressure-enhanced diffusion through dense polymer membranes, which has been shown in fluidized bed for animal cell culture.[5] We chose polytetrafluoroScheme 1. Hydrogenation of a) 2-N-acetylamidocinnamic acid (AAZ) with PyrPhos and b) NADP with the hydrogenase from Pyrococcus furiosus (PfH) (for NADP and NADPH only the reduced nicotinamide moiety is shown).

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Asymmetric Hydrogenation of α‐(Acetylamino)cinnamic Acid with a Novel Rhodium Complex; the Design of an Optimal Ligand

Cited by 71 publications

References 5 publications

Asymmetric epoxidation of chromenes catalyzed by chiral pyrrolidine SalenMn(III) complexes with an anchored functional group

Asymmetric epoxidation of chromenes catalyzed by chiral pyrrolidine SalenMn(III) complexes with an anchored functional group

(3S,4S)-1-Benzylpyrrolidine-3,4-diol

Membrane Aerated Hydrogenation: Enzymatic and Chemical Homogeneous Catalysis

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