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Mora Flores EW, Suarez D, Uhrig ML, Postigo A. Photocatalyzed Perfluoroalkylation of Endoglycals. J Org Chem 2023. [PMID: 38050850 DOI: 10.1021/acs.joc.3c01488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
The visible light-induced perfluoroalkyl (RF) radical reactions on peracetylglycals derived from hexoses and pentoses (galactal, glucal, arabinal, and xylal derivatives) were investigated. Various photocatalysts and perfluoroalkyl iodides (RF-I) were employed as sources of RF radicals with LEDs as the irradiation source. Particularly noteworthy was the use of an Iridium photocatalyst, Ir[dF(CF3)ppy]2(dtbpy))PF6, which yielded two distinct product types when applied to glucal. On the one hand, the 2-RF-substituted glucal was formed, a trend observed even when utilizing organic dyes as photocatalysts. On the other hand, the unexpected addition product, namely the 1-RF-2-iodo-α-manno-configured C-glycosyl derivative, was also obtained, as a result of a highly regioselective addition reaction of the RF moiety into the anomeric carbon, followed by attachment of the iodine atom on C-2 in axial disposition. This result contrasted with other radical reactions carried out on 2-unsubstituted glycals, where the incipient radical adds to C-2, generating a stabilized 1-glycosyl radical. The photocatalyzed radical perfluoroalkylations of peracetyl glycals derived from galactose, arabinose, and xylose all afforded the 2-RF-substituted glycals in good yields as a result of the expected vinylic substitution reaction. Mechanistic studies revealed that the 1-RF-2-iodo-α-manno-configured C-glycosyl derivatives arise from a radical chain reaction, whereas the 2-RF-substituted glycals proceed from inefficient chain processes.
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Affiliation(s)
- Erwin W Mora Flores
- Universidad de Buenos Aires, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Buenos Aires C1428EGA, Argentina
- CONICET-Universidad de Buenos Aires, Centro de Investigaciones en Hidratos de Carbono (CIHIDECAR), Ciudad Universitaria, Buenos Aires C1428EGA, Argentina
- Departamento de Ciencias Químicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires CP 1113, Argentina
| | - Daniel Suarez
- Universidad de Buenos Aires, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Buenos Aires C1428EGA, Argentina
- CONICET-Universidad de Buenos Aires, Centro de Investigaciones en Hidratos de Carbono (CIHIDECAR), Ciudad Universitaria, Buenos Aires C1428EGA, Argentina
- Departamento de Ciencias Químicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires CP 1113, Argentina
| | - María Laura Uhrig
- Universidad de Buenos Aires, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Buenos Aires C1428EGA, Argentina
- CONICET-Universidad de Buenos Aires, Centro de Investigaciones en Hidratos de Carbono (CIHIDECAR), Ciudad Universitaria, Buenos Aires C1428EGA, Argentina
| | - Al Postigo
- Departamento de Ciencias Químicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires CP 1113, Argentina
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Bielski R, Mencer D. New syntheses of thiosaccharides utilizing substitution reactions. Carbohydr Res 2023; 532:108915. [PMID: 37597327 DOI: 10.1016/j.carres.2023.108915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 07/30/2023] [Accepted: 07/31/2023] [Indexed: 08/21/2023]
Abstract
Novel synthetic methods published since 2005 affording carbohydrates containing sulfur atom(s) are reviewed. The review is divided to subchapters based on the position of sulfur atom(s) in the sugar molecule. Only those methods that take advantage of substitution are discussed.
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Affiliation(s)
- Roman Bielski
- Department of Pharmaceutical Sciences, Wilkes University, Wilkes-Barre, PA, 18766, United States; Chemventive, LLC Chadds Ford, PA, 19317, United States.
| | - Donald Mencer
- Department of Chemistry & Biochemistry, Wilkes University, Wilkes-Barre, PA, 18766, United States.
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Homolya Á, Jedlóczki I, Kónya-Ábrahám A, Somsák L, Tóth M, Juhász L. Behaviour of some 1-C-acceptor-substituted glycals under azidohydroxylation conditions. Carbohydr Res 2023; 529:108825. [PMID: 37253301 DOI: 10.1016/j.carres.2023.108825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 06/01/2023]
Abstract
Azidohydroxylation of 1-carbamoyl, 1-methoxycarbonyl and 1-cyano substituted d-lyxo and d-arabino configured O-peracylated glycals was studied and the reaction conditions were optimized. Under these conditions (3 equiv. NaN3/2 equiv. PIFA/0.3 equiv. TEMPO/50 equiv. H2O/dry DCM/0 °C/Ar) the expected 3-azido-3-deoxy ulopyranosonic acid derivatives were isolated in good yield with α-d-galacto configuration exclusively from the reaction of the 1-carbamoyl and 1-methoxycarbonyl substituted d-lyxo configured O-peracetylated glycals, while the transformation of the 1-cyano derivative gave a 2,3-vicinal diazide in low yield. The 1-carbamoyl d-arabino configured O-perbenzoylated glycal gave a mixture of α-d-gluco and α-d-manno configured azidohydroxylated products with d-gluco preference. The analogous 1-methoxycarbonyl derivative gave an inseparable product mixture and no transformation was detected with the respective 1-cyano glycal.
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Affiliation(s)
- Ágnes Homolya
- Department of Organic Chemistry, University of Debrecen, PO Box 400, H-4002, Debrecen, Hungary; University of Debrecen, Doctoral School of Chemistry, PO Box 400, H-4002, Debrecen, Hungary
| | - Ivett Jedlóczki
- Department of Organic Chemistry, University of Debrecen, PO Box 400, H-4002, Debrecen, Hungary
| | - Anita Kónya-Ábrahám
- Department of Organic Chemistry, University of Debrecen, PO Box 400, H-4002, Debrecen, Hungary
| | - László Somsák
- Department of Organic Chemistry, University of Debrecen, PO Box 400, H-4002, Debrecen, Hungary
| | - Marietta Tóth
- Department of Organic Chemistry, University of Debrecen, PO Box 400, H-4002, Debrecen, Hungary
| | - László Juhász
- Department of Organic Chemistry, University of Debrecen, PO Box 400, H-4002, Debrecen, Hungary.
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Affiliation(s)
- Giulio Goti
- Università degli Studi di Padova Dipartimento di Scienze Chimiche via Francesco Marzolo, 1 35131 Padova ITALY
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5
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Efficient Synthesis of Azido Sugars Using Fluorosulfuryl Azide Diazotransfer Reagent. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Homolya L, Juhász L, Somsák L. Halogen addition to some 1-C-substituted pyranoid glycals. Carbohydr Res 2021; 504:108292. [PMID: 33940310 DOI: 10.1016/j.carres.2021.108292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 11/21/2022]
Abstract
Addition of bromine and chlorine to O-peracylated 1-CN-, COOMe- and CONH2-substituted glycals was studied under ionic and radical conditions. The main or exclusive products were the corresponding 2,3-trans-diaxial (3-bromo-3-deoxy-α-d-heptopyranosylbromide)onic acid derivatives. Bromination of the O-peracetylated d-lyxo-hept-2-enopyranosononitrile and all chlorinations proved selective towards the 2-axial-3-equatorial (3-halogeno-3-deoxy-α-d-heptopyranosylhalide)onic acid derivatives. Silver triflate promoted glycosylation of methanol was successful with each 2,3-trans-diaxial (3-bromo-3-deoxy-α-d-heptopyranosylbromide)onic acid derivative, however, several attempted nucleophilic substitution and elimination reactions gave the parent glycal only.
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Affiliation(s)
- Levente Homolya
- Department of Organic Chemistry, University of Debrecen, POB 400, H-4002, Debrecen, Hungary
| | - László Juhász
- Department of Organic Chemistry, University of Debrecen, POB 400, H-4002, Debrecen, Hungary
| | - László Somsák
- Department of Organic Chemistry, University of Debrecen, POB 400, H-4002, Debrecen, Hungary.
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Jayaraman N. Display of Rich Reactivities of Endo- and Exocyclic Unsaturated Sugars that Parallel the Native Sugars. CHEM REC 2021; 21:3049-3062. [PMID: 33960656 DOI: 10.1002/tcr.202100091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/18/2021] [Accepted: 04/19/2021] [Indexed: 11/10/2022]
Abstract
Unsaturated monosaccharides expand the scope of reactivities in a sugar, directly leading to the development of newer methodologies, molecular structures and functional entities. The unsaturation as a reactive moiety can either be within the molecule, namely, endocyclic, or as a pendant moiety around the molecule, namely, exocyclic. One carbon homologations aided by reactions at the unsaturated moiety expand the molecular structures in both endo- and exocyclic sugars and lead to structures that are largely hitherto unknown. Molecular shifts and rearrangements permit interchanging the reactivities from one carbon to the other in unsaturated sugars. Activations of exocyclic unsaturated sugars also find newer possibilities to reactions central to the sugar chemistry, namely, the glycosylations. The personal reflections result from a couple of decades of explorations that traverse through the unsaturated sugars from different vantage points.
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