1
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Yoshino J, Hirono Y, Kaneda A, Hayashi N. Synthesis, structures, and solid-state photoresponsive color change behavior of boronium complexes bearing a pyridine-imine, diimine, or pyridine-ketone bidentate ligand. Dalton Trans 2023; 52:15017-15022. [PMID: 37812026 DOI: 10.1039/d3dt02332j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
9-Borabicyclo[3.3.1]nonane-based boronium triflates bearing a N-substituted 2-pyridylmethanimine, N,N'-dialkylethane-1,2-diimine, or 2-arylcarbonylpyridine ligand were synthesized. Their tetracoordinate boron structures were determined using 11B NMR spectra and X-ray crystallography. The pyridine-imine complexes exhibited solid-state photoresponsive color changes upon UV irradiation, which indicated that boronium complexes without a bipyridine moiety also have photoresponsive capabilities. Combination of TD-DFT calculations and measurements of UV-vis absorption and fluorescence properties, diffuse reflectance spectra, and ESR spectra provided suggestions on the determining factor of the photoresponsive color change capabilities and structures of the photoproducts.
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Affiliation(s)
- Junro Yoshino
- Faculty of Science, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan.
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Yoshito Hirono
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Ayako Kaneda
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Naoto Hayashi
- Faculty of Science, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan.
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
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2
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Clarke J, Seo Y, Gagné MR, Bender TA. Achieving Site-Selective C–O Bond Reduction for High-Value Cellulosic Valorization. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Joshua Clarke
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Youngran Seo
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Michel R. Gagné
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Trandon A. Bender
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia 23529, United States
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3
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Lowe JM, Seo Y, Clarke JJ, Gagné MR. Precyclization Conformer Profiles of -SiR 3+- and -Bcat +-Activated Linear Si-Protected Hexitols Explain Condensative Cyclization Selectivities. J Org Chem 2022; 87:12065-12071. [PMID: 36053236 DOI: 10.1021/acs.joc.2c01151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The condensative cyclization of sp3 C-O bonds in per-silylated hexitols is investigated by computation. Conformer searches using the Monte Carlo algorithm, followed by successively higher levels of theory (MMFF, PM3, and B3LYP), of -SiR3+- and -Bcat+-activated substrates lead to structures primed for intramolecular chemistry. Silane activation features O4 to C1 attack, while borane activation suggests boronium ions that activate O5 to C2 reactivity. This, in conjunction with Boltzmann population analysis, parallels reported reactivity for sorbitol, mannitol, and galactitol. Calculations using the meta-hybrid M06-2X functional additionally provide free-energy profiles for each cyclization event. In most of the cases presented, precyclization conformers that position a nucleophilic oxygen less than 3.0 Å from the C-O leaving group correlate to efficient experimental reactivities. Two examples of galactitol containing bridging silyl groups are analyzed computationally, and the experimental outcomes match predictions. The computational regime presented is a step closer to providing predictive power for the reduction of per-functionalized molecules.
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Affiliation(s)
- Jared M Lowe
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Youngran Seo
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Joshua J Clarke
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Michel R Gagné
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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4
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Kobylarski M, Berthet JC, Cantat T. Reductive depolymerization of polyesters and polycarbonates with hydroboranes by using a lanthanum(III) tris(amide) catalyst. Chem Commun (Camb) 2022; 58:2830-2833. [PMID: 35133392 DOI: 10.1039/d2cc00184e] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The homogeneous reductive depolymerization of polyesters and polycarbonates with hydroboranes is achieved with the use of an f-metal complex catalyst. These polymeric materials are transformed into their value-added alcohol equivalents. Catalysis proceeds readily, under mild conditions, with La[N(SiMe3)2]3 (1 mol%) and pinacolborane (HBpin) and shows high selectivity towards alcohols and diols, after hydrolysis.
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Affiliation(s)
| | | | - Thibault Cantat
- NIMBE, CEA Paris-Saclay, Gif-sur-Yvette Cedex 91191, France.
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5
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Seo Y, Lowe JM, Romano N, Gagné MR. Switching between X-Pyrano-, X-Furano-, and Anhydro- X-pyranoside Synthesis (X = C, N) under Lewis acid Catalyzed Conditions. Org Lett 2021; 23:5636-5640. [PMID: 34259527 DOI: 10.1021/acs.orglett.1c01713] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A variety of C-glycosides can be obtained from the fluoroarylborane (B(C6F5)3) or silylium (R3Si+) catalyzed functionalization of 1-MeO- and per-TMS-sugars with TMS-X reagents. A one-step functionalization with a change as simple as the addition order and/or Lewis acid and TMS-X enables one to afford chiral synthons that are common (C-pyranosides), have few viable synthetic methods (C-furanosides), or are virtually unknown (anhydro-C-pyranosides), which mechanistically arise from whether a direct substitution, isomerization/substitution, or substitution/isomerization occurs, respectively.
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Affiliation(s)
- Youngran Seo
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jared M Lowe
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Neyen Romano
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Michel R Gagné
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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6
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Szpara R, Goyder A, Porter MJ, Hailes HC, Sheppard TD. Regioselective Dehydration of Sugar Thioacetals under Mild Conditions. Org Lett 2021; 23:2488-2492. [PMID: 33729808 PMCID: PMC8041386 DOI: 10.1021/acs.orglett.1c00424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Sugars
are abundant in waste biomass, making them sustainable chiral
building blocks for organic synthesis. The demand for chiral saturated
heterocyclic rings for pharmaceutical applications is increasing as
they provide well-defined three-dimensional frameworks that show increased
metabolic resistance. A range of sugar thioacetals can be dehydrated
selectively at C-2 under mild basic conditions, and the resulting
ketene thioacetals can be applied to the production of useful chiral
building blocks via further selective dehydration reactions.
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Affiliation(s)
- Rachel Szpara
- Department of Chemistry, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
| | - Alexander Goyder
- Department of Chemistry, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
| | - Michael J Porter
- Department of Chemistry, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
| | - Helen C Hailes
- Department of Chemistry, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
| | - Tom D Sheppard
- Department of Chemistry, Christopher Ingold Laboratories, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
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7
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Yoshino J, Hirono Y, Akahane R, Higuchi H, Hayashi N. Effects of π-conjugation on the solid-state photoresponsive coloring behavior of bipyridine-boronium complexes. Photochem Photobiol Sci 2020; 19:1517-1521. [PMID: 33047774 DOI: 10.1039/d0pp00296h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Solid-state photoinduced coloring of boronium complexes consisting of 9-borabicyclononane and 2,2'-bipyridine with π-conjugated substituents at the 4,4'- or 5,5'-positions was investigated. The substitution position affected the highest occupied molecular orbital distribution and determined the coloring capability. The 4,4'-substituted complexes exhibited coloration upon irradiation, whereas most of the 5,5'-substituted complexes did not.
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Affiliation(s)
- Junro Yoshino
- Faculty of Science, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan. and Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Yoshito Hirono
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Ryota Akahane
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Hiroyuki Higuchi
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Naoto Hayashi
- Faculty of Science, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan. and Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
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8
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Holmstedt S, George L, Koivuporras A, Valkonen A, Candeias NR. Deoxygenative Divergent Synthesis: En Route to Quinic Acid Chirons. Org Lett 2020; 22:8370-8375. [PMID: 33002357 DOI: 10.1021/acs.orglett.0c02995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The installation of vicinal mesylate and silyl ether groups in a quinic acid derivative generates a system prone for stereoselective borane-catalyzed hydrosilylation through a siloxonium intermediate. The diversification of the reaction conditions allowed the construction of different defunctionalized fragments foreseen as useful synthetic fragments. The selectivity of the hydrosilylation was rationalized on the basis of deuteration experiments and computational studies.
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Affiliation(s)
- Suvi Holmstedt
- Faculty of Engineering and Natural Sciences, Tampere University, Korkeakoulunkatu 8, 33101 Tampere, Finland
| | - Lijo George
- Faculty of Engineering and Natural Sciences, Tampere University, Korkeakoulunkatu 8, 33101 Tampere, Finland
| | - Alisa Koivuporras
- Faculty of Engineering and Natural Sciences, Tampere University, Korkeakoulunkatu 8, 33101 Tampere, Finland
| | - Arto Valkonen
- Department of Chemistry, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland
| | - Nuno R Candeias
- Faculty of Engineering and Natural Sciences, Tampere University, Korkeakoulunkatu 8, 33101 Tampere, Finland.,LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
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9
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Lowe JM, Bowers BE, Seo Y, Gagné MR. Modulating Electrostatic Interactions in Ion Pair Intermediates To Alter Site Selectivity in the C−O Deoxygenation of Sugars. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202007415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Jared M. Lowe
- Department of Chemistry University of North Carolina at Chapel Hill Chapel Hill NC 27599 USA
| | - Bekah E. Bowers
- Department of Chemistry University of North Carolina at Chapel Hill Chapel Hill NC 27599 USA
| | - Youngran Seo
- Department of Chemistry University of North Carolina at Chapel Hill Chapel Hill NC 27599 USA
| | - Michel R. Gagné
- Department of Chemistry University of North Carolina at Chapel Hill Chapel Hill NC 27599 USA
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10
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Cao J, Tamura M, Hosaka R, Nakayama A, Hasegawa JY, Nakagawa Y, Tomishige K. Mechanistic Study on Deoxydehydration and Hydrogenation of Methyl Glycosides to Dideoxy Sugars over a ReO x–Pd/CeO 2 Catalyst. ACS Catal 2020. [DOI: 10.1021/acscatal.0c02309] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Ji Cao
- Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Masazumi Tamura
- Research Center for Artificial Photosynthesis, Advanced Research Institute for Natural Science and Technology, Osaka City University, Osaka 558-8585, Japan
| | - Ryu Hosaka
- Institute for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
| | - Akira Nakayama
- Institute for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
- Department of Chemical System Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Jun-ya Hasegawa
- Institute for Catalysis, Hokkaido University, Sapporo 001-0021, Japan
| | - Yoshinao Nakagawa
- Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - Keiichi Tomishige
- Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
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11
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Wang J, Shao P, Lin X, Ma B, Wen J, Zhang X. Facile Synthesis of Enantiopure Sugar Alcohols: Asymmetric Hydrogenation and Dynamic Kinetic Resolution Combined. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006661] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jiang Wang
- School of Chemical Biology and Biotechnology Peking University Shenzhen Graduate School University Town Nanshan District Shenzhen 518055 China
- Guangdong Provincial Key Laboratory of Catalysis Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
| | - Pan‐Lin Shao
- College of Innovation and Entrepreneurship Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
- Guangdong Provincial Key Laboratory of Catalysis Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
| | - Xin Lin
- College of Innovation and Entrepreneurship Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
| | - Baode Ma
- College of Innovation and Entrepreneurship Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
- Guangdong Provincial Key Laboratory of Catalysis Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
| | - Jialin Wen
- Guangdong Provincial Key Laboratory of Catalysis Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
- Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
| | - Xumu Zhang
- Guangdong Provincial Key Laboratory of Catalysis Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
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12
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Wang J, Shao P, Lin X, Ma B, Wen J, Zhang X. Facile Synthesis of Enantiopure Sugar Alcohols: Asymmetric Hydrogenation and Dynamic Kinetic Resolution Combined. Angew Chem Int Ed Engl 2020; 59:18166-18171. [DOI: 10.1002/anie.202006661] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/17/2020] [Indexed: 01/20/2023]
Affiliation(s)
- Jiang Wang
- School of Chemical Biology and Biotechnology Peking University Shenzhen Graduate School University Town Nanshan District Shenzhen 518055 China
- Guangdong Provincial Key Laboratory of Catalysis Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
| | - Pan‐Lin Shao
- College of Innovation and Entrepreneurship Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
- Guangdong Provincial Key Laboratory of Catalysis Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
| | - Xin Lin
- College of Innovation and Entrepreneurship Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
| | - Baode Ma
- College of Innovation and Entrepreneurship Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
- Guangdong Provincial Key Laboratory of Catalysis Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
| | - Jialin Wen
- Guangdong Provincial Key Laboratory of Catalysis Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
- Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
| | - Xumu Zhang
- Guangdong Provincial Key Laboratory of Catalysis Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
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13
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Fang H, Oestreich M. Defunctionalisation catalysed by boron Lewis acids. Chem Sci 2020; 11:12604-12615. [PMID: 34094457 PMCID: PMC8163203 DOI: 10.1039/d0sc03712e] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 07/22/2020] [Indexed: 12/22/2022] Open
Abstract
Selective defunctionalisation of organic molecules to valuable intermediates is a fundamentally important transformation in organic synthesis. Despite the advances made in efficient and selective defunctionalisation using transition-metal catalysis, the cost, toxicity, and non-renewable properties limit its application in industrial manufacturing processes. In this regard, boron Lewis acid catalysis has emerged as a powerful tool for the cleavage of carbon-heteroatom bonds. The ground-breaking finding is that the strong boron Lewis acid B(C6F5)3 can activate Si-H bonds through η1 coordination, and this Lewis adduct is a key intermediate that enables various reduction processes. This system can be tuned by variation of the electronic and structural properties of the borane catalyst, and together with different hydride sources high chemoselectivity can be achieved. This Perspective provides a comprehensive summary of various defunctionalisation reactions such as deoxygenation, decarbonylation, desulfurisation, deamination, and dehalogenation, all of which catalysed by boron Lewis acids.
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Affiliation(s)
- Huaquan Fang
- Institut für Chemie, Technische Universität Berlin Strasse des 17. Juni 115 10623 Berlin Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin Strasse des 17. Juni 115 10623 Berlin Germany
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14
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Lowe JM, Bowers BE, Seo Y, Gagné MR. Modulating Electrostatic Interactions in Ion Pair Intermediates To Alter Site Selectivity in the C-O Deoxygenation of Sugars. Angew Chem Int Ed Engl 2020; 59:17297-17300. [PMID: 32521102 DOI: 10.1002/anie.202007415] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Indexed: 11/09/2022]
Abstract
Controlling which products one can access from the predefined biomass-derived sugars is challenging. Changing from CH2 Cl2 to the greener alternative toluene alters which C-O bonds in a sugar are cleaved by the tris(pentafluorophenyl)borane/HSiR3 catalyst system. This increases the diversity of high-value products that can be obtained through one-step, high-yielding, catalytic transformations of the mono-, di-, and oligosaccharides. Computational methods helped identify this non-intuitive outcome in low dielectric solvents to non-isotropic electrostatic enhancements in the key ion pair intermediates, which influence the reaction coordinate in the reactivity-/selectivity-determining step. Molecular-level models for these effects have far-reaching consequences in stereoselective ion pair catalysis.
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Affiliation(s)
- Jared M Lowe
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Bekah E Bowers
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Youngran Seo
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Michel R Gagné
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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15
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Seo Y, Gudz A, Lowe JM, Gagné MR. Selective deoxygenation of gibberellic acid with fluoroarylborane catalysts. Tetrahedron 2019; 75. [PMID: 32523234 DOI: 10.1016/j.tet.2019.130712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Reductive late-stage functionalization of gibberellic acid is reported using three fluoroarylborane Lewis acids; (B(C6F5)3, B(3,5-C6H3(CF3)2), and B(2,4,6-C6H2F3)3) in combination with a tertiary silane and a borane (HBCat) reductant. In each case, C-O bond activation occurs, and different products are obtained depending on the reductant and catalyst employed.
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Affiliation(s)
- Youngran Seo
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Anton Gudz
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Jared M Lowe
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Michel R Gagné
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
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16
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Cao J, Tamura M, Nakagawa Y, Tomishige K. Direct Synthesis of Unsaturated Sugars from Methyl Glycosides. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00589] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ji Cao
- Department of Applied Chemistry, School of Engineering, Tohoku University, Aoba 6-6-07, Aramaki, Aoba-ku, Sendai, Miyagi 980−8579, Japan
| | - Masazumi Tamura
- Department of Applied Chemistry, School of Engineering, Tohoku University, Aoba 6-6-07, Aramaki, Aoba-ku, Sendai, Miyagi 980−8579, Japan
| | - Yoshinao Nakagawa
- Department of Applied Chemistry, School of Engineering, Tohoku University, Aoba 6-6-07, Aramaki, Aoba-ku, Sendai, Miyagi 980−8579, Japan
| | - Keiichi Tomishige
- Department of Applied Chemistry, School of Engineering, Tohoku University, Aoba 6-6-07, Aramaki, Aoba-ku, Sendai, Miyagi 980−8579, Japan
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