1
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Verma P, Pallerla RR, Rolig A, Pihko PM. Humilisin E: Strategy for the Synthesis and Access to the Functionalized Bicyclic Core. J Org Chem 2024. [PMID: 38670541 DOI: 10.1021/acs.joc.4c00358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024]
Abstract
Humilisin E is a diterpenoid possessing a rare epoxidized cyclononene trans-fused with a bicyclo[3.2.0]heptane core. We have identified the P atropisomer of the corresponding cyclononadiene as a potential biosynthetic/synthetic precursor to humilisin E and reported two different strategies for the stereocontrolled synthesis of the appropriately functionalized bicyclic cores of humilisin E. The first route involves a Stork epoxynitrile cyclization via a Mg alkoxide, and the second, more stereoselective approach utilizes the Wolff rearrangement as the key step.
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Affiliation(s)
- Prachi Verma
- Department of Chemistry and NanoScience Center, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - Rajanish R Pallerla
- Department of Chemistry and NanoScience Center, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - Aino Rolig
- Department of Chemistry and NanoScience Center, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - Petri M Pihko
- Department of Chemistry and NanoScience Center, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
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2
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Nechaev AA, Gonzalez G, Verma P, Peshkov VA, Bannykh A, Hashemi A, Hannonen J, Hamza A, Papai I, Laasonen K, Peljo P, Pihko PM. Exploration of Vitamin B6-Based Redox-Active Pyridinium Salts towards the Application in Aqueous Organic Flow Batteries. Chemistry 2024:e202400828. [PMID: 38640462 DOI: 10.1002/chem.202400828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/21/2024]
Abstract
Pyridoxal hydrochloride, a vitamin B6 vitamer, was synthetically converted to a series of diverse redox-active benzoyl pyridinium salts. Cyclic voltammetry studies demonstrated redox reversibility under basic conditions, and two of the most promising salts were subjected to laboratory-scale redox flow battery tests involving galvanostatic cycling at 10 mM in 0.1 M NaOH. In these tests, the battery was charged completely, corresponding to the transfer of two electrons to the electrolyte, but no discharge was observed. Both CV analysis and electrochemical simulations confirmed that the redox wave observed in the experimental voltammograms corresponds to a two-electron process. To explain the irreversibility in the battery tests, we conducted bulk electrolysis with the benzoyl pyridinium salts, affording the corresponding benzylic secondary alcohols. Computational studies suggest that the reduction proceeds in three consecutive steps: first electron transfer (ET), then proton-coupled electron transfer (PCET) and finally proton transfer (PT) to give the secondary alcohol. 1H NMR deuterium exchange studies indicated that the last PT step is not reversible in 0.1 M NaOH, rendering the entire redox process irreversible. The apparent reversibility observed in CV at the basic media likely arises from the slow rate of the PT step at the timescale of the measurement.
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Affiliation(s)
- Anton A Nechaev
- University of Jyväskylä, Department of Chemistry, 40014, Jyväskylä, FINLAND
| | - Gabriel Gonzalez
- University of Turku, Department of Mechanical and Materials Engineering, 20014, Turku, FINLAND
| | - Prachi Verma
- University of Jyväskylä, Department of Chemistry, 40014, Jyväskylä, FINLAND
| | - Vsevolod A Peshkov
- University of Jyväskylä, Department of Chemistry, 40014, Jyväskylä, FINLAND
| | - Anton Bannykh
- University of Jyväskylä, Department of Chemistry, 40014, Jyväskylä, FINLAND
| | - Arsalan Hashemi
- Aalto University, Department of Chemistry and Material Science, 02150, Espoo, FINLAND
| | - Jenna Hannonen
- University of Turku, Department of Mechanical and Materials Engineering, 20014, Turku, FINLAND
| | - Andrea Hamza
- MTA Research Centre for Natural Sciences, Institute of Organic Chemistry, 1117, Budapest, HUNGARY
| | - Imre Papai
- MTA Research Centre for Natural Sciences, Institute of Organic Chemistry, 1117, Budapest, HUNGARY
| | - Kari Laasonen
- Aalto University, Department of Chemistry and Material Science, 02150, Espoo, FINLAND
| | - Pekka Peljo
- University of Turku, Department of Mechanical and Materials Engineering, 20014, Turku, FINLAND
| | - Petri M Pihko
- University of Jyvaskyla, Department of Chemistry, Survontie 9, P.O.B. 35, FIN-40014 JYU, Jyväskylä, FINLAND
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3
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Bannykh A, Pihko PM. Carboxylate-Catalyzed C-Silylation of Terminal Alkynes. Org Lett 2024; 26:1991-1995. [PMID: 38428925 PMCID: PMC10949233 DOI: 10.1021/acs.orglett.3c04213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/01/2024] [Accepted: 02/07/2024] [Indexed: 03/03/2024]
Abstract
A carboxylate-catalyzed, metal-free C-silylation protocol for terminal alkynes is reported using a quaternary ammonium pivalate as the catalyst and commercially available N,O-bis(silyl)acetamides as silylating agents. The reaction proceeds under mild conditions, tolerates a range of functionalities, and enables concomitant O- or N-silylation of acidic OH or NH groups. A Hammett ρ value of +1.4 ± 0.1 obtained for para-substituted 2-arylalkynes is consistent with the proposed catalytic cycle involving a turnover-determining deprotonation step.
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Affiliation(s)
- Anton Bannykh
- Department of Chemistry and NanoScience
Center, University of Jyväskylä, P.O.B. 35, FI-40014 University of Jyväskylä, Finland
| | - Petri M. Pihko
- Department of Chemistry and NanoScience
Center, University of Jyväskylä, P.O.B. 35, FI-40014 University of Jyväskylä, Finland
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4
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Riuttamäki S, Bannykh A, Pihko PM. Carboxylate Catalysis: A Catalytic O-Silylative Aldol Reaction of Aldehydes and Ethyl Diazoacetate. J Org Chem 2023; 88:14396-14403. [PMID: 37768196 PMCID: PMC10594658 DOI: 10.1021/acs.joc.3c01304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Indexed: 09/29/2023]
Abstract
A mild catalytic variant of the aldol reaction between ethyl diazoacetate and aldehydes is described using a combination of N,O-bis(trimethylsilyl)acetamide and catalytic tetramethylammonium pivalate as catalyst. The reaction proceeds rapidly at ambient temperature to afford the O-silylated aldol products in good to excellent yield, and the acetamide byproducts can be removed by simple filtration.
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Affiliation(s)
| | | | - Petri M. Pihko
- Department of Chemistry and
NanoScience Center, University of Jyväskylä, P.O.B. 35, Jyväskylä FI-40014, Finland
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5
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Riuttamäki S, Laczkó G, Madarász Á, Földes T, Pápai I, Bannykh A, Pihko PM. Carboxylate Catalyzed Isomerization of β,γ‐Unsaturated
N
‐Acetylcysteamine Thioesters**. Chemistry 2022; 28:e202201030. [PMID: 35604200 PMCID: PMC9541288 DOI: 10.1002/chem.202201030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Indexed: 11/11/2022]
Abstract
We demonstrate herein the capacity of simple carboxylate salts – tetrametylammonium and tetramethylguanidinium pivalate – to act as catalysts in the isomerization of β,γ‐unsaturated thioesters to α,β‐unsaturated thioesters. The carboxylate catalysts gave reaction rates comparable to those obtained with DBU, but with fewer side reactions. The reaction exhibits a normal secondary kinetic isotope effect (k1H/k1D=1.065±0.026) with a β,γ‐deuterated substrate. Computational analysis of the mechanism provides a similar value (k1H/k1D=1.05) with a mechanism where γ‐reprotonation of the enolate intermediate is rate determining.
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Affiliation(s)
- Saara Riuttamäki
- Department of Chemistry University of Jyväskylä P.O. Box 35 40014 Jyväskylä Finland
| | - Gergely Laczkó
- Institute of Organic Chemistry Research Centre for Natural Sciences Magyar tudósok körútja 2 1117 Budapest Hungary
| | - Ádám Madarász
- Institute of Organic Chemistry Research Centre for Natural Sciences Magyar tudósok körútja 2 1117 Budapest Hungary
| | - Tamás Földes
- Institute of Organic Chemistry Research Centre for Natural Sciences Magyar tudósok körútja 2 1117 Budapest Hungary
| | - Imre Pápai
- Institute of Organic Chemistry Research Centre for Natural Sciences Magyar tudósok körútja 2 1117 Budapest Hungary
| | - Anton Bannykh
- Department of Chemistry University of Jyväskylä P.O. Box 35 40014 Jyväskylä Finland
| | - Petri M. Pihko
- Department of Chemistry University of Jyväskylä P.O. Box 35 40014 Jyväskylä Finland
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6
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Pápai I, Pihko PM, Siitonen JH, Csókás D. Total Synthesis of Stemoamide, 9a-epi-Stemoamide, and 9a,10-epi-Stemoamide: Divergent Stereochemistry of the Final Methylation Steps. Synlett 2020. [DOI: 10.1055/s-0040-1707201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Total syntheses of stemoamide, 9a-epi-stemoamide, and 9a,10-epi-stemoamide by a convergent A + B ring-forming strategy is reported. The synthesis required a diastereoselective late-stage methylation of the ABC stemoamide core that successfully enabled access to three of the four possible diastereomeric structures. For the natural stemoamide series, the diastereoselectivity can be rationalized both by kinetic and thermodynamic arguments, whereas for the natural 9a-epi-stemoamide series, the kinetic selectivity is explained by the prepyramidalization of the relevant enolate.
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Affiliation(s)
- Imre Pápai
- Institute of Organic Chemistry, Research Centre for Natural Sciences
- Institute of Organic Chemistry, Research Centre for Natural Sciences
| | - Petri M. Pihko
- Department of Chemistry and Nanoscience Centre, University of Jyvaskyla
| | - Juha H. Siitonen
- Department of Chemistry and Nanoscience Centre, University of Jyvaskyla
- Institute of Organic Chemistry, Research Centre for Natural Sciences
| | - Dániel Csókás
- Institute of Organic Chemistry, Research Centre for Natural Sciences
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7
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Csókás D, Siitonen JH, Pihko PM, Pápai I. Conformationally Locked Pyramidality Explains the Diastereoselectivity in the Methylation of trans-Fused Butyrolactones. Org Lett 2020; 22:4597-4601. [PMID: 32338517 PMCID: PMC7309317 DOI: 10.1021/acs.orglett.0c01008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
![]()
A stereoselectivity
model inspired by the total synthesis of stemona
alkaloids is developed to explain why enolate-derived 3,4-fused butyrolactones
are methylated with a preference for syn alkylation.
The model shows how conformational locking present in nonplanar enolate
structures favors syn over anti methylation,
due to less significant structural distortions in the syn pathway. The developed model was also successfully used to rationalize
selectivities of previously documented methylation reactions.
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Affiliation(s)
- Dániel Csókás
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Juha H Siitonen
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - Petri M Pihko
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - Imre Pápai
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
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8
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Abstract
A concise enantio- and stereocontrolled synthesis of (+)-lycoperdic acid is presented. The stereochemical control is based on iminium-catalyzed Mukaiyama-Michael reaction and enamine-catalyzed organocatalytic α-chlorination steps. The amino group was introduced by azide displacement, affording the final stereochemistry of (+)-lycoperdic acid. Penultimate hydrogenation and hydrolysis afforded pure (+)-lycoperdic acid in seven steps from a known silyloxyfuran.
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Affiliation(s)
- Sami Kortet
- Department of Chemistry and NanoScience Center, University of Jyväskylä, Survontie 9B, 40520 Jyväskylä, Finland
| | - Aurélie Claraz
- Department of Chemistry and NanoScience Center, University of Jyväskylä, Survontie 9B, 40520 Jyväskylä, Finland
| | - Petri M Pihko
- Department of Chemistry and NanoScience Center, University of Jyväskylä, Survontie 9B, 40520 Jyväskylä, Finland
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9
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Mustalahti S, Morozov D, Luk HL, Pallerla RR, Myllyperkiö P, Pettersson M, Pihko PM, Groenhof G. Photoactive Yellow Protein Chromophore Photoisomerizes around a Single Bond if the Double Bond Is Locked. J Phys Chem Lett 2020; 11:2177-2181. [PMID: 32109070 PMCID: PMC7145348 DOI: 10.1021/acs.jpclett.0c00060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
Photoactivation in the Photoactive Yellow Protein, a bacterial blue-light photoreceptor, proceeds via photoisomerization of the double C═C bond in the covalently attached chromophore. Quantum chemistry calculations, however, have suggested that in addition to double-bond photoisomerization, the isolated chromophore and many of its analogues can isomerize around a single C-C bond as well. Whereas double-bond photoisomerization has been observed with X-ray crystallography, experimental evidence of single-bond photoisomerization is currently lacking. Therefore, we have synthesized a chromophore analogue, in which the formal double bond is covalently locked in a cyclopentenone ring, and carried out transient absorption spectroscopy experiments in combination with nonadiabatic molecular dynamics simulations to reveal that the locked chromophore isomerizes around the single bond upon photoactivation. Our work thus provides experimental evidence of single-bond photoisomerization in a photoactive yellow protein chromophore analogue and suggests that photoisomerization is not restricted to the double bonds in conjugated systems. This insight may be useful for designing light-driven molecular switches or motors.
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10
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Neuvonen AJ, Noutsias D, Topić F, Rissanen K, Földes T, Pápai I, Pihko PM. Dynamic Refolding of Ion-Pair Catalysts in Response to Different Anions. J Org Chem 2019; 84:15009-15019. [PMID: 31536339 DOI: 10.1021/acs.joc.9b01980] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Four distinct folding patterns are identified in two foldamer-type urea-thiourea catalysts bearing a basic dimethylamino unit by a combination of X-ray crystallography, solution NMR studies, and computational studies (DFT). These patterns are characterized by different intramolecular hydrogen bonding schemes that arise largely from different thiourea conformers. The free base forms of the catalysts are characterized by folds where the intramolecular hydrogen bonds between the urea and the thiourea units remain intact. In contrast, the catalytically relevant salt forms of the catalyst, where the catalyst forms an ion pair with the substrate or substrate analogues, appear in two entirely different folding patterns. With larger anions that mimic the dialkyl malonate substrates, the catalysts maintain their native fold both in the solid state and in solution, but with smaller halide anions (fluoride, chloride, and bromide), the catalysts fold around the halide anion (anion receptor fold), and the intramolecular hydrogen bonds are disrupted. Titration of catalyst hexafluoroacetylacetonate salt with tetra-n-butylammonium chloride results in dynamic refolding of the catalyst from the native fold to the anion receptor fold.
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Affiliation(s)
- Antti J Neuvonen
- Department of Chemistry and NanoScience Center , University of Jyväskylä , FI-40014 Jyväskylä , Finland
| | - Dimitris Noutsias
- Department of Chemistry and NanoScience Center , University of Jyväskylä , FI-40014 Jyväskylä , Finland
| | - Filip Topić
- Department of Chemistry and NanoScience Center , University of Jyväskylä , FI-40014 Jyväskylä , Finland
| | - Kari Rissanen
- Department of Chemistry and NanoScience Center , University of Jyväskylä , FI-40014 Jyväskylä , Finland
| | - Tamás Földes
- Institute of Organic Chemistry, Research Centre for Natural Sciences , Hungarian Academy of Sciences , Magyar tudósok körútja 2 , H-1117 Budapest , Hungary
| | - Imre Pápai
- Institute of Organic Chemistry, Research Centre for Natural Sciences , Hungarian Academy of Sciences , Magyar tudósok körútja 2 , H-1117 Budapest , Hungary
| | - Petri M Pihko
- Department of Chemistry and NanoScience Center , University of Jyväskylä , FI-40014 Jyväskylä , Finland
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11
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Földes T, Madarász Á, Révész Á, Dobi Z, Varga S, Hamza A, Nagy PR, Pihko PM, Pápai I. Stereocontrol in Diphenylprolinol Silyl Ether Catalyzed Michael Additions: Steric Shielding or Curtin–Hammett Scenario? J Am Chem Soc 2017; 139:17052-17063. [DOI: 10.1021/jacs.7b07097] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Tamás Földes
- Institute
of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Ádám Madarász
- Institute
of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Ágnes Révész
- Institute
of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Zoltán Dobi
- Institute
of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Szilárd Varga
- Institute
of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Andrea Hamza
- Institute
of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
| | - Péter R. Nagy
- MTA-BME
Lendület Quantum Chemistry Research Group, Department of Physical
Chemistry and Materials Science, Budapest University of Technology and Economics, P.O. Box 91, H-1521 Budapest, Hungary
| | - Petri M. Pihko
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - Imre Pápai
- Institute
of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary
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12
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Affiliation(s)
- Antti J. Neuvonen
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 Jyväskylän yliopisto, Finland
| | - Tamás Földes
- Research
Center for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok
körútja 2, H-1117 Budapest, Hungary
| | - Ádám Madarász
- Research
Center for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok
körútja 2, H-1117 Budapest, Hungary
| | - Imre Pápai
- Research
Center for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok
körútja 2, H-1117 Budapest, Hungary
| | - Petri M. Pihko
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 Jyväskylän yliopisto, Finland
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13
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Tuokko S, Honkala K, Pihko PM. Pd/C-Catalyzed Hydrosilylation of Enals and Enones with Triethylsilane: Conformer Populations Control the Stereoselectivity. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02856] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sakari Tuokko
- Department of Chemistry,
Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland
| | - Karoliina Honkala
- Department of Chemistry,
Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland
| | - Petri M. Pihko
- Department of Chemistry,
Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland
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14
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Tuokko S, Pihko PM, Honkala K. First Principles Calculations for Hydrogenation of Acrolein on Pd and Pt: Chemoselectivity Depends on Steric Effects on the Surface. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201507631] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sakari Tuokko
- Department of Chemistry; Nanoscience Center; University of Jyväskylä; P.O. Box 35 40014 Jyväskylä Finland
| | - Petri M. Pihko
- Department of Chemistry; Nanoscience Center; University of Jyväskylä; P.O. Box 35 40014 Jyväskylä Finland
| | - Karoliina Honkala
- Department of Chemistry; Nanoscience Center; University of Jyväskylä; P.O. Box 35 40014 Jyväskylä Finland
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15
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Tuokko S, Pihko PM, Honkala K. First Principles Calculations for Hydrogenation of Acrolein on Pd and Pt: Chemoselectivity Depends on Steric Effects on the Surface. Angew Chem Int Ed Engl 2016; 55:1670-4. [DOI: 10.1002/anie.201507631] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 11/13/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Sakari Tuokko
- Department of Chemistry; Nanoscience Center; University of Jyväskylä; P.O. Box 35 40014 Jyväskylä Finland
| | - Petri M. Pihko
- Department of Chemistry; Nanoscience Center; University of Jyväskylä; P.O. Box 35 40014 Jyväskylä Finland
| | - Karoliina Honkala
- Department of Chemistry; Nanoscience Center; University of Jyväskylä; P.O. Box 35 40014 Jyväskylä Finland
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16
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Suhonen A, Kortelainen M, Nauha E, Yliniemelä-Sipari S, Pihko PM, Nissinen M. Conformational properties and folding analysis of a series of seven oligoamide foldamers. CrystEngComm 2016. [DOI: 10.1039/c5ce02458g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Claraz A, Sahoo G, Berta D, Madarász Á, Pápai I, Pihko PM. A Catalyst Designed for the Enantioselective Construction of Methyl- and Alkyl-Substituted Tertiary Stereocenters. Angew Chem Int Ed Engl 2015; 55:669-73. [DOI: 10.1002/anie.201509302] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Indexed: 12/26/2022]
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18
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Claraz A, Sahoo G, Berta D, Madarász Á, Pápai I, Pihko PM. A Catalyst Designed for the Enantioselective Construction of Methyl- and Alkyl-Substituted Tertiary Stereocenters. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201509302] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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19
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Kortelainen M, Suhonen A, Hamza A, Pápai I, Nauha E, Yliniemelä-Sipari S, Nissinen M, Pihko PM. Folding Patterns in a Family of Oligoamide Foldamers. Chemistry 2015; 21:9493-504. [PMID: 25965104 DOI: 10.1002/chem.201406521] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Indexed: 11/07/2022]
Abstract
A series of small, unsymmetrical pyridine-2,6-dicarboxylamide oligoamide foldamers with varying lengths and substituents at the end groups were synthetized to study their conformational properties and folding patterns. The @-type folding pattern resembled the oxyanion-hole motifs of enzymes, but several alternative folding patterns could also be characterized. Computational studies revealed several alternative conformers of nearly equal stability. These folding patterns differed from each other in their intramolecular hydrogen-bonding patterns and aryl-aryl interactions. In the solid state, the foldamers adopted either the globular @-type fold or the more extended S-type conformers, which were very similar to those foldamers obtained computationally. In some cases, the same foldamer molecule could even crystallize into two different folding patterns, thus confirming that the different folding patterns are very close in energy in spite of their completely different shapes. Finally, the best match for the observed NOE interactions in the liquid state was a conformation that matched the computationally characterized helix-type fold.
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Affiliation(s)
- Minna Kortelainen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 JYU (Finland), Fax: (+358) 14-260-2501
| | - Aku Suhonen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 JYU (Finland), Fax: (+358) 14-260-2501
| | - Andrea Hamza
- Institute of Organic Chemistry, Research Center for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok Körútja 2, 1117, Budapest (Hungary)
| | - Imre Pápai
- Institute of Organic Chemistry, Research Center for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok Körútja 2, 1117, Budapest (Hungary).
| | - Elisa Nauha
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 JYU (Finland), Fax: (+358) 14-260-2501
| | - Sanna Yliniemelä-Sipari
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 JYU (Finland), Fax: (+358) 14-260-2501
| | - Maija Nissinen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 JYU (Finland), Fax: (+358) 14-260-2501.
| | - Petri M Pihko
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O. Box 35, 40014 JYU (Finland), Fax: (+358) 14-260-2501.
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20
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Tuokko S, Pihko PM. Palladium on Charcoal as a Catalyst for Stoichiometric Chemo- and Stereoselective Hydrosilylations and Hydrogenations with Triethylsilane. Org Process Res Dev 2014. [DOI: 10.1021/op5003209] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Sakari Tuokko
- Department
of Chemistry and
NanoScience Center, University of Jyväskylä, P.O.B. 35, FI-40014 JYU, Jyväskylä, Finland
| | - Petri M. Pihko
- Department
of Chemistry and
NanoScience Center, University of Jyväskylä, P.O.B. 35, FI-40014 JYU, Jyväskylä, Finland
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21
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Neuvonen AJ, Pihko PM. Enantioselective Mannich Reaction of β-Keto Esters with Aromatic and Aliphatic Imines Using a Cooperatively Assisted Bifunctional Catalyst. Org Lett 2014; 16:5152-5. [DOI: 10.1021/ol5025025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Antti J. Neuvonen
- Department
of Chemistry and
NanoScience Center, University of Jyväskylä, Survontie 9B, 40520 Jyväskylä, Finland
| | - Petri M. Pihko
- Department
of Chemistry and
NanoScience Center, University of Jyväskylä, Survontie 9B, 40520 Jyväskylä, Finland
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22
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Leskinen MV, Madarász Á, Yip KT, Vuorinen A, Pápai I, Neuvonen AJ, Pihko PM. Cross-Dehydrogenative Couplings between Indoles and β-Keto Esters: Ligand-Assisted Ligand Tautomerization and Dehydrogenation via a Proton-Assisted Electron Transfer to Pd(II). J Am Chem Soc 2014; 136:6453-62. [DOI: 10.1021/ja501681y] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Mikko V. Leskinen
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - Ádám Madarász
- Research
Center for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudosok
Korutja 2, H-1117, Budapest, Hungary
| | - Kai-Tai Yip
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - Aini Vuorinen
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - Imre Pápai
- Research
Center for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudosok
Korutja 2, H-1117, Budapest, Hungary
| | - Antti J. Neuvonen
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland
| | - Petri M. Pihko
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland
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23
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Kemppainen EK, Sahoo G, Piisola A, Hamza A, Kótai B, Pápai I, Pihko PM. Mukaiyama-Michael Reactions withtrans-2,5-Diarylpyrrolidine Catalysts: Enantioselectivity Arises from Attractive Noncovalent Interactions, Not from Steric Hindrance. Chemistry 2014; 20:5983-93. [DOI: 10.1002/chem.201304240] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Indexed: 11/12/2022]
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24
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Jijy E, Prakash P, Shimi M, Pihko PM, Joseph N, Radhakrishnan KV. Rhodium catalyzed oxidative coupling of salicylaldehydes with diazabicyclic olefins: a one pot strategy involving aldehyde C-H cleavage and π-allyl chemistry towards the synthesis of fused ring chromanones. Chem Commun (Camb) 2014; 49:7349-51. [PMID: 23846351 DOI: 10.1039/c3cc43485k] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
An efficient one pot strategy for the synthesis of cyclopentene fused chromanone derivatives through the direct oxidative coupling of salicylaldehydes with bicyclic olefins in the presence of a rhodium-copper catalyst system is described. This is the first report on the ring opening-ring closing of bicyclic hydrazines via metal catalyzed oxidative coupling reaction.
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Affiliation(s)
- E Jijy
- Organic Chemistry Section, Chemical Sciences and Technology Division, National Institute for Interdisciplinary Science and Technology (CSIR), Trivandrum 695 019, India
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25
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Erkkilä A, Pihko PM. Correction to Mild Organocatalytic α-Methylenation of Aldehydes. J Org Chem 2013. [DOI: 10.1021/jo401861r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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26
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Kemppainen EK, Sahoo G, Valkonen A, Pihko PM. Mukaiyama–Michael Reactions with Acrolein and Methacrolein: A Catalytic Enantioselective Synthesis of the C17–C28 Fragment of Pectenotoxins. Org Lett 2013. [DOI: 10.1021/ol402460b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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Prakash P, Jijy E, Preethanuj P, Pihko PM, Sarath Chand S, Radhakrishnan KV. Palladium-Catalyzed Skeletal Rearrangement of Spirotricyclic Olefins: A Facile One-Pot Strategy for the Synthesis of a Novel Motif with Cyclopentene Fused to Benzofuran and Pyrazolidine. Chemistry 2013; 19:10473-7. [DOI: 10.1002/chem.201301475] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Indexed: 12/20/2022]
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28
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Nimje RY, Leskinen MV, Pihko PM. A Three-Component Palladium-Catalyzed Oxidative CC Coupling Reaction: A Domino Process in Two Dimensions. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201300833] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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29
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Nimje RY, Leskinen MV, Pihko PM. A three-component palladium-catalyzed oxidative C-C coupling reaction: a domino process in two dimensions. Angew Chem Int Ed Engl 2013; 52:4818-22. [PMID: 23553956 DOI: 10.1002/anie.201300833] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Roshan Y Nimje
- Department of Chemistry and NanoScience Center, University of Jyväskylä, P. O. B. 35, 40014 JYU, Finland
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30
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Joseph N, Rajan R, John J, Devika NV, Chand SS, Suresh E, Pihko PM, Radhakrishnan KV. An exclusive approach to 3,4-disubstituted cyclopentenes and alkylidene cyclopentenes via the palladium catalyzed ring opening of azabicyclic olefins with aryl halides. RSC Adv 2013. [DOI: 10.1039/c3ra41504j] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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31
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Sahoo G, Rahaman H, Madarász Á, Pápai I, Melarto M, Valkonen A, Pihko PM. Dihydrooxazine Oxides as Key Intermediates in Organocatalytic Michael Additions of Aldehydes to Nitroalkenes. Angew Chem Int Ed Engl 2012; 51:13144-8. [DOI: 10.1002/anie.201204833] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 10/10/2012] [Indexed: 11/09/2022]
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32
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Sahoo G, Rahaman H, Madarász Á, Pápai I, Melarto M, Valkonen A, Pihko PM. Dihydrooxazine Oxides as Key Intermediates in Organocatalytic Michael Additions of Aldehydes to Nitroalkenes. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201204833] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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33
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Yip KT, Nimje RY, Leskinen MV, Pihko PM. Palladium-Catalyzed Dehydrogenative β′-Arylation of β-Keto Esters under Aerobic Conditions: Interplay of Metal and Brønsted Acids. Chemistry 2012; 18:12590-4. [DOI: 10.1002/chem.201201988] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Indexed: 11/08/2022]
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34
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Probst N, Madarász Á, Valkonen A, Pápai I, Rissanen K, Neuvonen A, Pihko PM. Cooperative Assistance in Bifunctional Organocatalysis: Enantioselective Mannich Reactions with Aliphatic and Aromatic Imines. Angew Chem Int Ed Engl 2012; 51:8495-9. [DOI: 10.1002/anie.201203852] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Nicolas Probst
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O.B. 35, 40014 JYU (Finland) http://tinyurl.com/pihkogroup
| | - Ádám Madarász
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.B. 17, 1525 Budapest (Hungary)
| | - Arto Valkonen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O.B. 35, 40014 JYU (Finland) http://tinyurl.com/pihkogroup
| | - Imre Pápai
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.B. 17, 1525 Budapest (Hungary)
| | - Kari Rissanen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O.B. 35, 40014 JYU (Finland) http://tinyurl.com/pihkogroup
| | - Antti Neuvonen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O.B. 35, 40014 JYU (Finland) http://tinyurl.com/pihkogroup
| | - Petri M. Pihko
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O.B. 35, 40014 JYU (Finland) http://tinyurl.com/pihkogroup
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35
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Probst N, Madarász Á, Valkonen A, Pápai I, Rissanen K, Neuvonen A, Pihko PM. Cooperative Assistance in Bifunctional Organocatalysis: Enantioselective Mannich Reactions with Aliphatic and Aromatic Imines. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201203852] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nicolas Probst
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O.B. 35, 40014 JYU (Finland) http://tinyurl.com/pihkogroup
| | - Ádám Madarász
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.B. 17, 1525 Budapest (Hungary)
| | - Arto Valkonen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O.B. 35, 40014 JYU (Finland) http://tinyurl.com/pihkogroup
| | - Imre Pápai
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.B. 17, 1525 Budapest (Hungary)
| | - Kari Rissanen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O.B. 35, 40014 JYU (Finland) http://tinyurl.com/pihkogroup
| | - Antti Neuvonen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O.B. 35, 40014 JYU (Finland) http://tinyurl.com/pihkogroup
| | - Petri M. Pihko
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O.B. 35, 40014 JYU (Finland) http://tinyurl.com/pihkogroup
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36
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Leskinen MV, Yip KT, Valkonen A, Pihko PM. Palladium-Catalyzed Dehydrogenative β′-Functionalization of β-Keto Esters with Indoles at Room Temperature. J Am Chem Soc 2012; 134:5750-3. [DOI: 10.1021/ja300684r] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Mikko V. Leskinen
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 JYU,
Finland
| | - Kai-Tai Yip
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 JYU,
Finland
| | - Arto Valkonen
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 JYU,
Finland
| | - Petri M. Pihko
- Department
of Chemistry and NanoScience Center, University of Jyväskylä, FI-40014 JYU,
Finland
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38
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Kemppainen EK, Sahoo G, Valkonen A, Pihko PM. Mukaiyama–Michael Reactions with Acrolein and Methacrolein: A Catalytic Enantioselective Synthesis of the C17–C28 Fragment of Pectenotoxins. Org Lett 2012; 14:1086-9. [DOI: 10.1021/ol203486p] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Eeva K. Kemppainen
- Department of Chemistry and Nanoscience Center, University of Jyväskylä, POB 35, FIN-40014 JYU, Finland
| | - Gokarneswar Sahoo
- Department of Chemistry and Nanoscience Center, University of Jyväskylä, POB 35, FIN-40014 JYU, Finland
| | - Arto Valkonen
- Department of Chemistry and Nanoscience Center, University of Jyväskylä, POB 35, FIN-40014 JYU, Finland
| | - Petri M. Pihko
- Department of Chemistry and Nanoscience Center, University of Jyväskylä, POB 35, FIN-40014 JYU, Finland
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39
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Venkatesan R, Alahuhta M, Pihko PM, Wierenga RK. High resolution crystal structures of triosephosphate isomerase complexed with its suicide inhibitors: the conformational flexibility of the catalytic glutamate in its closed, liganded active site. Protein Sci 2011; 20:1387-97. [PMID: 21633986 PMCID: PMC3189524 DOI: 10.1002/pro.667] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 05/19/2011] [Indexed: 01/07/2023]
Abstract
The key residue of the active site of triosephosphate isomerase (TIM) is the catalytic glutamate, which is proposed to be important (i) as a catalytic base, for initiating the reaction, as well as (ii) for the subsequent proton shuttling steps. The structural properties of this glutamate in the liganded complex have been investigated by studying the high resolution crystal structures of typanosomal TIM, complexed with three suicide inhibitors: (S)-glycidol phosphate ((S)-GOP, at 0.99 Å resolution), (R)-glycidol phosphate, ((R)-GOP, at 1.08 Å resolution), and bromohydroxyacetone phosphate (BHAP, at 1.97 Å resolution). The structures show that in the (S)-GOP active site this catalytic glutamate is in the well characterized, competent conformation. However, an unusual side chain conformation is observed in the (R)-GOP and BHAP complexes. In addition, Glu97, salt bridged to the catalytic lysine in the competent active site, adopts an unusual side chain conformation in these two latter complexes. The higher chemical reactivity of (S)-GOP compared with (R)-GOP, as known from solution studies, can be understood: the structures indicate that in the case of (S)-GOP, Glu167 can attack the terminal carbon of the epoxide in a stereoelectronically favored, nearly linear OCO arrangement, but this is not possible for the (R)-GOP isomer. These structures confirm the previously proposed conformational flexibility of the catalytic glutamate in its closed, liganded state. The importance of this conformational flexibility for the proton shuttling steps in the TIM catalytic cycle, which is apparently achieved by a sliding motion of the side chain carboxylate group above the enediolate plane, is also discussed.
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Affiliation(s)
- Rajaram Venkatesan
- Biocenter Oulu and Department of Biochemistry, FIN 90014, University of OuluFinland
| | - Markus Alahuhta
- Biocenter Oulu and Department of Biochemistry, FIN 90014, University of OuluFinland
| | - Petri M Pihko
- Department of Chemistry and Nanoscience Center, University of Jyväskylä, FIN 40014, University of JyväskyläFinland
| | - Rik K Wierenga
- Biocenter Oulu and Department of Biochemistry, FIN 90014, University of OuluFinland,*Correspondence to: Rik K. Wierenga, Biocenter Oulu and Department of Biochemistry, P.O. Box 3000, FIN 90014, University of Oulu, Finland. E-mail:
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40
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Benohoud M, Tuokko S, Pihko PM. Stereoselective Hydrosilylation of Enals and Enones Catalysed by Palladium Nanoparticles. Chemistry 2011; 17:8404-13. [DOI: 10.1002/chem.201100655] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Indexed: 11/11/2022]
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41
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Rahaman H, Madarász Á, Pápai I, Pihko PM. Dual Hydrogen-Bond/Enamine Catalysis Enables a Direct Enantioselective Three-Component Domino Reaction. Angew Chem Int Ed Engl 2011; 50:6123-7. [DOI: 10.1002/anie.201101835] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Indexed: 11/11/2022]
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42
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Rahaman H, Madarász Á, Pápai I, Pihko PM. Dual Hydrogen-Bond/Enamine Catalysis Enables a Direct Enantioselective Three-Component Domino Reaction. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201101835] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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43
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Aho JE, Piisola A, Syam Krishnan K, Pihko PM. Synthetic Studies towards Pectenotoxin-2: Synthesis of the Nonanomeric 10-epi-ABCDE Ring Segment by Kinetic Spiroketalization. European J Org Chem 2011. [DOI: 10.1002/ejoc.201001411] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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44
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Pápai I, Hamza A, Pihko PM, Wierenga RK. Stereoelectronic Requirements for Optimal Hydrogen-Bond-Catalyzed Enolization. Chemistry 2011; 17:2859-66. [DOI: 10.1002/chem.201002943] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Indexed: 11/07/2022]
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45
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Pohjakallio A, Pihko PM, Liu J. Base-Catalyzed Isomerization of 2-Isoxazolines Enables a Two-Step Enantioselective Synthesis of β-Hydroxynitriles from Enals. J Org Chem 2010; 75:6712-5. [DOI: 10.1021/jo1013788] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Antti Pohjakallio
- Department of Chemistry, Aalto University School of Science and Technology, Kemistintie 1, FI-02150 Espoo, Finland
| | - Petri M. Pihko
- Department of Chemistry, University of Jyväskylä, FI-40014 JYU, Finland
| | - Jun Liu
- Department of Chemistry, University of Jyväskylä, FI-40014 JYU, Finland
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Pohjakallio A, Pihko PM, Laitinen UM. Synthesis of 2-Isoxazolines: Enantioselective and Racemic Methods Based on Conjugate Additions of Oximes. Chemistry 2010; 16:11325-39. [DOI: 10.1002/chem.201000861] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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47
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Aho JE, Salomäki E, Rissanen K, Pihko PM. Synthetic Studies Toward Pectenotoxin 2. Part I. Stereocontrolled Access to the C10−C22 Fragment. Org Lett 2008; 10:4179-82. [DOI: 10.1021/ol8015868] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jatta E. Aho
- Department of Chemistry, Helsinki University of Technology, POB 6100, FI-02015 TKK, Finland, and Department of Chemistry, University of Jyväskylä, POB 35, FI-40014 University of Jyväskylä, Finland
| | - Elina Salomäki
- Department of Chemistry, Helsinki University of Technology, POB 6100, FI-02015 TKK, Finland, and Department of Chemistry, University of Jyväskylä, POB 35, FI-40014 University of Jyväskylä, Finland
| | - Kari Rissanen
- Department of Chemistry, Helsinki University of Technology, POB 6100, FI-02015 TKK, Finland, and Department of Chemistry, University of Jyväskylä, POB 35, FI-40014 University of Jyväskylä, Finland
| | - Petri M. Pihko
- Department of Chemistry, Helsinki University of Technology, POB 6100, FI-02015 TKK, Finland, and Department of Chemistry, University of Jyväskylä, POB 35, FI-40014 University of Jyväskylä, Finland
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Affiliation(s)
- Hannes Helmboldt
- Department of Chemistry, Helsinki University of Technology, POB 6100, FI-02015 TKK, Finland, and Department of Chemistry, University of Jyväskylä, POB 35, FI-40014 University of Jyväskylä, Finland
| | - Jatta E. Aho
- Department of Chemistry, Helsinki University of Technology, POB 6100, FI-02015 TKK, Finland, and Department of Chemistry, University of Jyväskylä, POB 35, FI-40014 University of Jyväskylä, Finland
| | - Petri M. Pihko
- Department of Chemistry, Helsinki University of Technology, POB 6100, FI-02015 TKK, Finland, and Department of Chemistry, University of Jyväskylä, POB 35, FI-40014 University of Jyväskylä, Finland
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Affiliation(s)
- Anniina Erkkilä
- Laboratory of Organic Chemistry, Department of Chemical Technology, Helsinki University of Technology, P.O. Box 6100, FI-02015 TKK, Finland
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