Solvolysis of Formylphenyl Esters by a Bifunctional Peptide Catalyst

The multicomponent synthesis of prolyl pseudo-peptide catalysts using the Ugi reaction with furfurylamines or isocyanides is described. The incorporation of such a polymerizable furan handle enabled the subsequent polymerization of the peptide catalyst with furfuryl alcohol, thus rendering polyfurfuryl alcohol-supported catalysts for applications in heterogeneous enamine catalysis. The utilization of the polymer-supported catalysts in both batch and continuous-flow organocatalytic procedures proved moderate catalytic efficacy and enantioselectivity, but excellent diastereoselectivity in the asymmetric Michael addition of n-butanal to β-nitrostyrene that was used as a model reaction. This work supports the potential of multicomponent reactions towards the assembly of catalysts and their simultaneous functionalization for immobilization.

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ChemInform Abstract: Efficient Asymmetric α-Oxyamination of Aldehydes by Resin-Supported Peptide Catalyst in Aqueous Media.

ChemInform ◽

10.1002/chin.201035147 ◽

2010 ◽

Vol 41 (35) ◽

pp. no-no

Author(s):

Kengo Akagawa ◽

Takuma Fujiwara ◽

Seiji Sakamoto ◽

Kazuaki Kudo

Keyword(s):

Aqueous Media ◽

Peptide Catalyst

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Efficient Asymmetric α-Oxyamination of Aldehydes by Resin-Supported Peptide Catalyst in Aqueous Media

Organic Letters ◽

10.1021/ol100415h ◽

2010 ◽

Vol 12 (8) ◽

pp. 1804-1807 ◽

Cited By ~ 65

Author(s):

Kengo Akagawa ◽

Takuma Fujiwara ◽

Seiji Sakamoto ◽

Kazuaki Kudo

Keyword(s):

Aqueous Media ◽

Peptide Catalyst

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Effect of the Helical Tether of a Resin-Supported Peptide Catalyst for Friedel-Crafts-Type Alkylation in Water

Advanced Synthesis & Catalysis ◽

10.1002/adsc.201100950 ◽

2012 ◽

Vol 354 (7) ◽

pp. 1280-1286 ◽

Cited By ~ 29

Author(s):

Kengo Akagawa ◽

Rieko Suzuki ◽

Kazuaki Kudo

Keyword(s):

Peptide Catalyst

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Polypeptide-catalyzed Biosilicification of Dentin Surfaces

Journal of Dental Research ◽

10.1177/0022034509333838 ◽

2009 ◽

Vol 88 (4) ◽

pp. 377-381 ◽

Cited By ~ 7

Author(s):

A.J. Goldberg ◽

M.C. Advincula ◽

T. Komabayashi ◽

P.A. Patel ◽

P.T. Mather ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Treatment Strategies ◽

Marine Species ◽

X Ray ◽

Mineral Particles ◽

Peptide Catalysts ◽

Wide Range ◽

Negative Controls ◽

Peptide Catalyst

In situ formation of mineral particles by biocatalysis would be advantageous for occluding dentin tubules to reduce permeability or for sealing of material-tooth interfaces. One approach would require that the peptide-catalyst remain functional on the dentin surface. Based on recent observations of retained activity on other surfaces, we hypothesized that poly(L-lysine) (PLL), an analog of the protein catalyst responsible for silica formation in primitive marine species, would remain functional on dentin. PLL was applied to dentin discs along with a pre-hydrolyzed silica precursor, tetramethyl orthosilicate (TMOS). Discs were analyzed microscopically (scanning electron microscopy, SEM) and chemically (x-ray photoelectron spectroscopy, XPS). The treated discs, but not the negative controls, exhibited partial distinct coating whose XPS survey was consistent with that of silica, demonstrating that the polypeptide was required and retained its mediating activity. Peptide-catalysts that mediate mineral formation can retain functionality on dentin, suggesting a wide range of preventive and treatment strategies.

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Organocatalyzed C–C Ring Construction: The Carreira Synthesis of (+)-Crotogoudin

Organic Synthesis ◽

10.1093/oso/9780190646165.003.0069 ◽

2017 ◽

Author(s):

Douglass F. Taber

Keyword(s):

National Laboratory ◽

Unsaturated Aldehyde ◽

Materia Medica ◽

University Of New Mexico ◽

Effective Strategies ◽

Ester Enolate ◽

Robinson Annulation ◽

The University ◽

Peptide Catalyst

Kazuaki Kudo of the University of Tokyo developed (Org. Lett. 2013, 15, 4964) a peptide catalyst for the enantioselective construction of 3 by the addition of 2 to 1. Thorsten Bach of the Technische Universität München devised (Science 2013, 342, 840; J. Am. Chem. Soc. 2013, 135, 14948) a Lewis acid organocatalyst for the photocyclization of 4 to 5. Albert Moyano of the Universitat de Barcelona effected (Eur. J. Org. Chem. 2013, 3103) enantioselective conjugate addition of 7 to 6 to give the cyclopentane 8. Daniel Romo of Texas A&M optimized (Nature Chem. 2013, 5, 1049) the addition of 9 to 10 to give the β-lactone 11. Kamal Kumar and Herbert Waldmann of the Technische Universität Dortmund found (Angew. Chem. Int. Ed. 2013, 52, 9576) that the addition of 12 to 13 followed by Bayer–Villiger oxidation and deacylation delivered 14 in high ee. David W. Lupton of Monash University opened (Angew. Chem. Int. Ed. 2013, 52, 9149) the cyclopropane of 15 in situ, leading to an ester enolate that added to 16 to give 17. Jeffrey S. Johnson of the University of North Carolina used (Chem. Sci. 2013, 4, 2828) an organocatalyst to mediate the addition of the prochiral 18 to 19, leading to 20. M. Belén Cid of the Universidad Autónoma de Madrid added (J. Org. Chem. 2013, 78, 10737) the nitroalkane 22 to the unsaturated aldehyde 21, leading, after intramolecular Julia-Kocienski addition, to the cyclohexene 23. Additions that proceed in high ee with cyclopentenone and cyclohexenone are often not as selective with cycloheptenone 24. Wei Wang of the University of New Mexico and Wenhu Duan of the Shanghai Institute of Materia Medica observed (Tetrahedron Lett. 2013, 54, 3791) that addition of nitromethane and of nitroethane to 24 were both highly effective. Strategies have been developed for applying organocatalysis to the assembly of polycarbacyclic ring systems. Sanzhong Luo of the Beijing National Laboratory for Molecule Sciences uncovered (Synthesis 2013, 45, 1939) a simple amine that efficiently catalyzed the Robinson annulation of 26 with 27 to give 28.

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Article

Canadian Journal of Chemistry ◽

10.1139/v99-103 ◽

1999 ◽

Vol 77 (5-6) ◽

pp. 990-996

Author(s):

Jonas Nilsson ◽

Kerstin S Broo ◽

Richard S Sott ◽

Lars Baltzer

Keyword(s):

Acid Catalysis ◽

De Novo ◽

Order Rate Constant ◽

Second Order ◽

Amino Acid Residues ◽

Order Rate ◽

Helix Loop Helix ◽

Helical Segment ◽

Peptide Catalyst ◽

Hydrolysis Of

Peptides with 42 amino acid residues have been designed to fold into helix-loop-helix motifs that dimerize to form four-helix bundles and catalyze the hydrolysis of p-nitrophenyl esters. Their reactivities depend on nucleophilic and general-acid catalysis by cooperative HisH+-His pairs. The peptide catalyst MNV with the HisH+-His pair separated by three residues within the helical segment catalyzes the hydrolysis of p-nitrophenyl fumarate with a second-order rate constant of 0.034 M-1 s-1 at pH 5.1 and 290 K. This i, i+3 site is a factor of three more efficient than the corresponding i, i+4 site. Helix-loop-helix peptides having histidines situated at opposing helices were designed and exhibited cooperative HisH+-His catalytic pairs. The peptide H11,34K hydrolyzed p-nitrophenyl acetate and p-nitrophenyl valerate with second-order rate constants of 0.044 and 0.15 M-1 s-1, respectively, at pH 5.1 and 290 K, indicating that the hydrophobic substituent was recognized by the catalyst.Key words: de novo design, helix-loop-helix, four-helix bundle, histidine, catalysis.

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