51
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Geeson M, Cummins CC. Let's Make White Phosphorus Obsolete. ACS CENTRAL SCIENCE 2020; 6:848-860. [PMID: 32607432 PMCID: PMC7318074 DOI: 10.1021/acscentsci.0c00332] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Indexed: 05/20/2023]
Abstract
Industrial and laboratory methods for incorporating phosphorus atoms into molecules within the framework of Green Chemistry are in their infancy. Current practice requires large inputs of energy, involves toxic intermediates, and generates substantial waste. Furthermore, a negligible fraction of phosphorus-containing waste is recycled which in turn contributes to negative environmental impacts, such as eutrophication. Methods that begin to address some of these drawbacks are reviewed, and some key opportunities to be realized by pursuing organophosphorus chemistry under the principles of Green Chemistry are highlighted. Methods used by nature, or in the chemistry of other elements such as silicon, are discussed as model processes for the future of phosphorus in chemical synthesis.
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52
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Gray PA, Braun JD, Rahimi N, Herbert DE. Diiminepyridine‐Supported Phosphorus(I) and Phosphorus(III) Complexes: Synthesis, Characterization, and Electrochemistry. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000250] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Paul A. Gray
- Department of Chemistry and the Manitoba Institute for Materials University of Manitoba 144 Dysart Road R3T 2N2 Winnipeg Manitoba Canada
| | - Jason D. Braun
- Department of Chemistry and the Manitoba Institute for Materials University of Manitoba 144 Dysart Road R3T 2N2 Winnipeg Manitoba Canada
| | - Naser Rahimi
- Department of Chemistry and the Manitoba Institute for Materials University of Manitoba 144 Dysart Road R3T 2N2 Winnipeg Manitoba Canada
| | - David E. Herbert
- Department of Chemistry and the Manitoba Institute for Materials University of Manitoba 144 Dysart Road R3T 2N2 Winnipeg Manitoba Canada
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53
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Bagi P, Herbay R, Péczka N, Mucsi Z, Timári I, Keglevich AG. Preparation of 2-phospholene oxides by the isomerization of 3-phospholene oxides. Beilstein J Org Chem 2020; 16:818-832. [PMID: 32395185 PMCID: PMC7189000 DOI: 10.3762/bjoc.16.75] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 03/31/2020] [Indexed: 12/19/2022] Open
Abstract
A series of 1-substituted-3-methyl-2-phospholene oxides was prepared from the corresponding 3-phospholene oxides by double bond rearrangement. The 2-phospholene oxides could be obtained by heating the 3-phospholene oxides in methanesulfonic acid, or via the formation of cyclic chlorophosphonium salts. Whereas mixtures of the 2- and 3-phospholene oxides formed, when the isomerization of 3-phospholene oxides was attempted under thermal conditions, or in the presence of a base. The mechanisms of the various double bond migration pathways were elucidated by quantum chemical calculations.
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Affiliation(s)
- Péter Bagi
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
| | - Réka Herbay
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
| | - Nikolett Péczka
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
| | | | - István Timári
- Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4032 Debrecen, Hungary
| | - And György Keglevich
- Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
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54
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Zi Y, Schömberg F, Wagner K, Vilotijevic I. C–H Functionalization of Benzothiazoles via Thiazol-2-yl-phosphonium Intermediates. Org Lett 2020; 22:3407-3411. [DOI: 10.1021/acs.orglett.0c00882] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- You Zi
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University, Jena, Humboldtstr. 10, 07743 Jena, Germany
| | - Fritz Schömberg
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University, Jena, Humboldtstr. 10, 07743 Jena, Germany
| | - Konrad Wagner
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University, Jena, Humboldtstr. 10, 07743 Jena, Germany
| | - Ivan Vilotijevic
- Institute of Organic Chemistry and Macromolecular Chemistry, Friedrich Schiller University, Jena, Humboldtstr. 10, 07743 Jena, Germany
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55
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Zhang H, Zhou R. Recent Advances in Phosphine‐Promoted (4 + 1) Annulation Reactions. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000023] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Heng Zhang
- College of Chemistry and Chemical Engineering Taiyuan University of Technology 030024 Taiyuan P. R. China
| | - Rong Zhou
- College of Chemistry and Chemical Engineering Taiyuan University of Technology 030024 Taiyuan P. R. China
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56
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Li G, Nykaza TV, Cooper JC, Ramirez A, Luzung MR, Radosevich AT. An Improved P III/P V═O-Catalyzed Reductive C-N Coupling of Nitroaromatics and Boronic Acids by Mechanistic Differentiation of Rate- and Product-Determining Steps. J Am Chem Soc 2020; 142:6786-6799. [PMID: 32178514 PMCID: PMC7146866 DOI: 10.1021/jacs.0c01666] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
![]()
Experimental,
spectroscopic, and computational studies are reported
that provide an evidence-based mechanistic description of an intermolecular
reductive C–N coupling of nitroarenes and arylboronic acids
catalyzed by a redox-active main-group catalyst (1,2,2,3,4,4-hexamethylphosphetane P-oxide, i.e., 1·[O]). The central observations
include the following: (1) catalytic reduction of 1·[O]
to PIII phosphetane 1 is kinetically fast
under conditions of catalysis; (2) phosphetane 1 represents
the catalytic resting state as observed by 31P NMR spectroscopy;
(3) there are no long-lived nitroarene partial-reduction intermediates
observable by 15N NMR spectroscopy; (4) the reaction is
sensitive to solvent dielectric, performing best in moderately polar
solvents (viz. cyclopentylmethyl ether); and (5) the reaction is largely
insensitive with respect to common hydrosilane reductants. On the
basis of the foregoing studies, new modified catalytic conditions
are described that expand the reaction scope and provide for mild
temperatures (T ≥ 60 °C), low catalyst
loadings (≥2 mol%), and innocuous terminal reductants (polymethylhydrosiloxane).
DFT calculations define a two-stage deoxygenation sequence for the
reductive C–N coupling. The initial deoxygenation involves
a rate-determining step that consists of a (3+1) cheletropic addition
between the nitroarene substrate and phosphetane 1; energy
decomposition techniques highlight the biphilic character of the phosphetane
in this step. Although kinetically invisible, the second deoxygenation
stage is implicated as the critical C–N product-forming event,
in which a postulated oxazaphosphirane intermediate is diverted from
arylnitrene dissociation toward heterolytic ring opening with the
arylboronic acid; the resulting dipolar intermediate evolves by antiperiplanar
1,2-migration of the organoboron residue to nitrogen, resulting in
displacement of 1·[O] and formation of the target
C–N coupling product upon in situ hydrolysis.
The method thus described constitutes a mechanistically well-defined
and operationally robust main-group complement to the current workhorse
transition-metal-based methods for catalytic intermolecular C–N
coupling.
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Affiliation(s)
- Gen Li
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Trevor V Nykaza
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Julian C Cooper
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Antonio Ramirez
- Chemical and Synthetic Development, Bristol-Myers Squibb Company, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Michael R Luzung
- Chemical and Synthetic Development, Bristol-Myers Squibb Company, One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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57
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Nykaza TV, Li G, Yang J, Luzung MR, Radosevich AT. P
III
/P
V
=O Catalyzed Cascade Synthesis of N‐Functionalized Azaheterocycles. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201914851] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Trevor V. Nykaza
- Department of ChemistryMassachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Gen Li
- Department of ChemistryMassachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Junyu Yang
- Department of ChemistryMassachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | | | - Alexander T. Radosevich
- Department of ChemistryMassachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
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58
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Nykaza TV, Li G, Yang J, Luzung MR, Radosevich AT. P III /P V =O Catalyzed Cascade Synthesis of N-Functionalized Azaheterocycles. Angew Chem Int Ed Engl 2020; 59:4505-4510. [PMID: 31869510 DOI: 10.1002/anie.201914851] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/12/2019] [Indexed: 12/19/2022]
Abstract
An organocatalytic method for the modular synthesis of diverse N-aryl and N-alkyl azaheterocycles (indoles, oxindoles, benzimidazoles, and quinoxalinediones) is reported. The method employs a small-ring organophosphorus-based catalyst (1,2,2,3,4,4-hexamethylphosphetane P-oxide) and a hydrosilane reductant to drive the conversion of ortho-functionalized nitroarenes into azaheterocycles through sequential intermolecular reductive C-N cross coupling with boronic acids, followed by intramolecular cyclization. This method enables the rapid construction of azaheterocycles from readily available building blocks, including a regiospecific approach to N-substituted benzimidazoles and quinoxalinediones.
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Affiliation(s)
- Trevor V Nykaza
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Gen Li
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Junyu Yang
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Michael R Luzung
- Kallyope Inc., 430 E. 29th St., Suite 1050, New York, NY, 10016, USA
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
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59
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Longwitz L, Werner T. Reduction of Activated Alkenes by P
III
/P
V
Redox Cycling Catalysis. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201912991] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Lars Longwitz
- OrganocatalysisLeibniz-Institute for Catalysis Albert-Einstein-Straße 29a Rostock Germany
| | - Thomas Werner
- OrganocatalysisLeibniz-Institute for Catalysis Albert-Einstein-Straße 29a Rostock Germany
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60
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Longwitz L, Werner T. Reduction of Activated Alkenes by P III /P V Redox Cycling Catalysis. Angew Chem Int Ed Engl 2020; 59:2760-2763. [PMID: 31793147 PMCID: PMC7027467 DOI: 10.1002/anie.201912991] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/18/2019] [Indexed: 01/09/2023]
Abstract
The carbon-carbon double bond of unsaturated carbonyl compounds was readily reduced by using a phosphetane oxide catalyst in the presence of a simple organosilane as the terminal reductant and water as the hydrogen source. Quantitative hydrogenation was observed when 1.0 mol % of a methyl-substituted phosphetane oxide was employed as the catalyst. The procedure is highly selective towards activated double bonds, tolerating a variety of functional groups that are usually prone to reduction. In total, 25 alkenes and two alkynes were hydrogenated to the corresponding alkanes in excellent yields of up to 99 %. Notably, less active poly(methylhydrosiloxane) could also be utilized as the terminal reductant. Mechanistic investigations revealed the phosphane as the catalyst resting state and a protonation/deprotonation sequence as the crucial step in the catalytic cycle.
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Affiliation(s)
- Lars Longwitz
- Organocatalysis, Leibniz-Institute for Catalysis, Albert-Einstein-Straße 29a, Rostock, Germany
| | - Thomas Werner
- Organocatalysis, Leibniz-Institute for Catalysis, Albert-Einstein-Straße 29a, Rostock, Germany
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61
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Nykaza TV, Cooper JC, Radosevich AT. a nti-1,2,2,3,4,4-Hexamethylphosphetane 1-oxide. ACTA ACUST UNITED AC 2020; 96:418-435. [PMID: 31902967 DOI: 10.15227/orgsyn.096.0418] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Trevor V Nykaza
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Julian C Cooper
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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62
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Zhang J, Hao J, Huang Z, Han J, He Z. PIII-Mediated intramolecular cyclopropanation and metal-free synthesis of cyclopropane-fused heterocycles. Chem Commun (Camb) 2020; 56:10251-10254. [DOI: 10.1039/d0cc04086j] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The carbene-like reactivity of the Kukhtin–Ramirez adduct enables the first reductive intramolecular cyclopropanation, which provides easy access to highly functionalized cyclopropane-fused heterocycles.
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Affiliation(s)
- Jiayong Zhang
- State Key Laboratory of Elemento-Organic Chemistry
- College of Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
| | - Jiahang Hao
- State Key Laboratory of Elemento-Organic Chemistry
- College of Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
| | - Zhiqiang Huang
- State Key Laboratory of Elemento-Organic Chemistry
- College of Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
| | - Jie Han
- State Key Laboratory of Elemento-Organic Chemistry
- College of Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
| | - Zhengjie He
- State Key Laboratory of Elemento-Organic Chemistry
- College of Chemistry
- Nankai University
- Tianjin 300071
- P. R. China
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63
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Espinosa Ferao A, García Alcaraz A. Benchmarking the inversion barriers in σ3λ3-phosphorus compounds: a computational study. NEW J CHEM 2020. [DOI: 10.1039/d0nj01237h] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Benchmark study of three mechanisms for inversion at phosphorus, including parametric criteria for classification and analysis of factors affecting barriers.
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Affiliation(s)
- Arturo Espinosa Ferao
- Departamento de Química Orgánica
- Facultad de Química
- Campus de Espinardo
- Universidad de Murcia
- 30100 Murcia
| | - Antonio García Alcaraz
- Departamento de Química Orgánica
- Facultad de Química
- Campus de Espinardo
- Universidad de Murcia
- 30100 Murcia
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64
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Luo SQ, Liu W, Ruan BF, Fan SL, Zhu HX, Tao W, Xiao H. P(NMe2)3 mediated cyclopropanation of α-methylene-β-lactams for rapid syntheses of spirocyclopropyl β-lactams. Org Biomol Chem 2020; 18:4599-4603. [DOI: 10.1039/d0ob00826e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A P(NMe2)3-promoted cyclopropanation of a C3-substituted α-methylene-β-lactam provides a rapid and user-friendly method to obtain pharmaceutically intriguing spirocyclopropyl β-lactams under mild reaction conditions.
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Affiliation(s)
- Si-Qin Luo
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei 230601
- China
| | - Wei Liu
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei 230601
- China
| | - Ban-Feng Ruan
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei 230601
- China
| | - Shi-Lu Fan
- Department of Chemistry
- Hefei University of Technology
- Hefei
- China
| | - Hui-Xia Zhu
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei 230601
- China
| | - Wei Tao
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei 230601
- China
| | - Hua Xiao
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei 230601
- China
- Key Laboratory of Synthetic Chemistry of Natural Substances
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65
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Convergent Synthesis of Polysubstituted Furans via Catalytic Phosphine Mediated Multicomponent Reactions. Molecules 2019; 24:molecules24244595. [PMID: 31888142 PMCID: PMC6943692 DOI: 10.3390/molecules24244595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 11/29/2022] Open
Abstract
Tri- or tetrasubstituted furans have been prepared from terminal activated olefins and acyl chlorides or anhydrides by a multicomponental convergent synthesis mode. Instead of stoichiometric nBu3P, only catalytic nBu3P or nBu3P=O is needed to furnish the furans in modest to excellent yields with a good functional group tolerance under the aid of reducing agent silane. This synthetic method features a silane-driven catalytic intramolecular Wittig reaction as a key annulation step and represents the first successful application of catalytic Wittig reaction in multicomponent cascade reaction.
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66
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Eckert KE, Lepore AJ, Ashfeld BL. A Phosphorus(III)‐Mediated (4+1)‐Cycloaddition of 1,2‐Dicarbonyls and Aza‐
o
‐Quinone Methides to Access 2,3‐Dihydroindoles. Helv Chim Acta 2019. [DOI: 10.1002/hlca.201900192] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Kaitlyn E. Eckert
- Department of Chemistry and Biochemistry University of Notre Dame Notre Dame IN 46556 United States
| | - Antonio J. Lepore
- Department of Chemistry and Biochemistry University of Notre Dame Notre Dame IN 46556 United States
| | - Brandon L. Ashfeld
- Department of Chemistry and Biochemistry University of Notre Dame Notre Dame IN 46556 United States
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67
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Longwitz L, Spannenberg A, Werner T. Phosphetane Oxides as Redox Cycling Catalysts in the Catalytic Wittig Reaction at Room Temperature. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02456] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Lars Longwitz
- Leibniz-Institute for Catalysis e.V. at the University of Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany
| | - Anke Spannenberg
- Leibniz-Institute for Catalysis e.V. at the University of Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany
| | - Thomas Werner
- Leibniz-Institute for Catalysis e.V. at the University of Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany
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68
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Lecomte M, Lipshultz JM, Kim-Lee SH, Li G, Radosevich AT. Driving Recursive Dehydration by P III/P V Catalysis: Annulation of Amines and Carboxylic Acids by Sequential C-N and C-C Bond Formation. J Am Chem Soc 2019; 141:12507-12512. [PMID: 31345031 PMCID: PMC6693942 DOI: 10.1021/jacs.9b06277] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
A method
for the annulation of amines and carboxylic acids to form
pharmaceutically relevant azaheterocycles via organophosphorus PIII/PV redox catalysis is reported. The method employs
a phosphetane catalyst together with a mild bromenium oxidant and
terminal hydrosilane reductant to drive successive C–N and
C–C bond-forming dehydration events via the serial action of
a catalytic bromophosphonium intermediate. These results demonstrate
the capacity of PIII/PV redox catalysis to enable
iterative redox-neutral transformations in complement to the common
reductive driving force of the PIII/PV couple.
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Affiliation(s)
- Morgan Lecomte
- Department of Chemistry , Massachusetts Institute of Technology , 02139 Cambridge , Massachusetts , United States
| | - Jeffrey M Lipshultz
- Department of Chemistry , Massachusetts Institute of Technology , 02139 Cambridge , Massachusetts , United States
| | - Shin-Ho Kim-Lee
- Department of Chemistry , Massachusetts Institute of Technology , 02139 Cambridge , Massachusetts , United States.,Departamento de Química Orgánica, Facultad de Ciencias , Universidad Autónoma de Madrid , Cantoblanco, 28049 Madrid , Spain
| | - Gen Li
- Department of Chemistry , Massachusetts Institute of Technology , 02139 Cambridge , Massachusetts , United States
| | - Alexander T Radosevich
- Department of Chemistry , Massachusetts Institute of Technology , 02139 Cambridge , Massachusetts , United States
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69
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Lenstra DC, Wolf JJ, Mecinović J. Catalytic Staudinger Reduction at Room Temperature. J Org Chem 2019; 84:6536-6545. [PMID: 31050295 DOI: 10.1021/acs.joc.9b00831] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We report an efficient catalytic Staudinger reduction at room temperature that enables the preparation of a structurally diverse set of amines from azides in excellent yields. The reaction is based on the use of catalytic amounts of triphenylphosphine as a phosphine source and diphenyldisiloxane as a reducing agent. Our catalytic Staudinger reduction exhibits a high chemoselectivity, as exemplified by reduction of azides over other common functionalities, including nitriles, alkenes, alkynes, esters, and ketones.
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Affiliation(s)
- Danny C Lenstra
- Institute for Molecules and Materials , Radboud University , Heyendaalseweg 135 , Nijmegen 6525 AJ , The Netherlands
| | - Joris J Wolf
- Institute for Molecules and Materials , Radboud University , Heyendaalseweg 135 , Nijmegen 6525 AJ , The Netherlands
| | - Jasmin Mecinović
- Institute for Molecules and Materials , Radboud University , Heyendaalseweg 135 , Nijmegen 6525 AJ , The Netherlands.,Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , Campusvej 55 , Odense 5230 , Denmark
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70
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Abstract
A catalytic transfer-hydrogenation utilizing a well-defined Bi(I) complex as catalyst and ammonia-borane as transfer agent has been developed. This transformation represents a unique example of low-valent pnictogen catalysis cycling between oxidation states I and III, and proved useful for the hydrogenation of azoarenes and the partial reduction of nitroarenes. Interestingly, the bismuthinidene catalyst performs well in the presence of low-valent transition-metal sensitive functional groups and presents orthogonal reactivity compared to analogous phosphorus-based catalysis. Mechanistic investigations suggest the intermediacy of an elusive bismuthine species, which is proposed to be responsible for the hydrogenation and the formation of hydrogen.
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Affiliation(s)
- Feng Wang
- Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1 , Mülheim an der Ruhr , 45470 , Germany
| | - Oriol Planas
- Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1 , Mülheim an der Ruhr , 45470 , Germany
| | - Josep Cornella
- Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1 , Mülheim an der Ruhr , 45470 , Germany
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71
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Mörsdorf JM, Wadepohl H, Ballmann J. A Tautomeric λ 3/λ 5-Phosphane Pair and Its Ambiphilic Reactivity. Inorg Chem 2019; 58:3502-3508. [PMID: 30777436 DOI: 10.1021/acs.inorgchem.9b00076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The central phosphorus atom of a novel hydroxyl-functionalized triarylphosphane was shown to reversibly insert into one of the molecule's O-H bonds, which forms the basis for a tautomeric λ3/λ5-phosphane equilibrium. For the first time, this equilibrium was detected for a λ3-triarylphosphane and the underlying dynamic process was elucidated by NMR spectroscopy. On the basis of reactivity studies, a nucleophilic character was assigned to the minor species present in solution, the λ3-phosphane. Upon methylation, for example, the λ3-form was selectively removed from the equilibrium and converted to the corresponding phosphonium salt. However, upon generation of an alkoxide via proton abstraction, the electrophilic character of the λ5-phosphane in the equilibrium became evident since the alkoxide was found to attack the molecule's phosphorus atom. This intramolecular reaction led to the selective formation of a new anionic λ6-hydridospirophosphane.
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Affiliation(s)
- Jean-Marc Mörsdorf
- Anorganisch-Chemisches Institut , Ruprecht-Karls-Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut , Ruprecht-Karls-Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
| | - Joachim Ballmann
- Anorganisch-Chemisches Institut , Ruprecht-Karls-Universität Heidelberg , Im Neuenheimer Feld 276 , 69120 Heidelberg , Germany
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72
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Beddoe RH, Sneddon HF, Denton RM. The catalytic Mitsunobu reaction: a critical analysis of the current state-of-the-art. Org Biomol Chem 2019; 16:7774-7781. [PMID: 30306184 DOI: 10.1039/c8ob01929k] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The Mitsunobu reaction is widely regarded as the pre-eminent method for performing nucleophilic substitutions of alcohols with inversion of configuration. However, its applicability to large-scale synthesis is undermined by the fact that alcohol activation occurs at the expense of two stoichiometric reagents - a phosphine and an azodicarboxylate. The ideal Mitsunobu reaction would be sub-stoichiometric in the phosphine and azodicarboxylate species and employ innocuous terminal oxidants and reductants to achieve recycling. This Review article provides a summary and analysis of recent advances towards the development of such catalytic Mitsunobu reactions.
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Affiliation(s)
- Rhydian H Beddoe
- School of Chemistry, University of Nottingham; GlaxoSmithKline Carbon Neutral Laboratory, 6 Triumph Road, Nottingham, NG7 2GA, UK.
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73
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Ghosh A, Lecomte M, Kim-Lee SH, Radosevich AT. Organophosphorus-Catalyzed Deoxygenation of Sulfonyl Chlorides: Electrophilic (Fluoroalkyl)sulfenylation by P III /P V =O Redox Cycling. Angew Chem Int Ed Engl 2019; 58:2864-2869. [PMID: 30632657 DOI: 10.1002/anie.201813919] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Indexed: 11/07/2022]
Abstract
A method for electrophilic sulfenylation by organophosphorus-catalyzed deoxygenative O-atom transfer from sulfonyl chlorides is reported. This C-S bond-forming reaction is catalyzed by a readily available small-ring phosphine (phosphetane) in conjunction with a hydrosilane terminal reductant to afford a general entry to sulfenyl electrophiles, including valuable trifluoromethyl, perfluoroalkyl, and heteroaryl derivatives that are otherwise difficult to access. Mechanistic investigations indicate that the twofold deoxygenation of the sulfonyl substrate proceeds by the intervention of an off-cycle resting state thiophosphonium ion. The catalytic method represents an operationally simple protocol using a stable phosphine oxide as a precatalyst and exhibits broad functional-group tolerance.
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Affiliation(s)
- Avipsa Ghosh
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Morgan Lecomte
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Shin-Ho Kim-Lee
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.,Departamento de Química Orgánica, Facultad de Ciencias, Universidad Autónoma de Madrid (UAM), Cantoblanco, 28049, Madrid, Spain
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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74
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Ghosh A, Lecomte M, Kim‐Lee S, Radosevich AT. Organophosphorus‐Catalyzed Deoxygenation of Sulfonyl Chlorides: Electrophilic (Fluoroalkyl)sulfenylation by P
III
/P
V
=O Redox Cycling. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201813919] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Avipsa Ghosh
- Department of ChemistryMassachusetts Institute of Technology Cambridge MA 02139 USA
| | - Morgan Lecomte
- Department of ChemistryMassachusetts Institute of Technology Cambridge MA 02139 USA
| | - Shin‐Ho Kim‐Lee
- Department of ChemistryMassachusetts Institute of Technology Cambridge MA 02139 USA
- Departamento de Química OrgánicaFacultad de CienciasUniversidad Autónoma de Madrid (UAM) Cantoblanco 28049 Madrid Spain
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75
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Nykaza TV, Cooper JC, Li G, Mahieu N, Ramirez A, Luzung MR, Radosevich AT. Intermolecular Reductive C-N Cross Coupling of Nitroarenes and Boronic Acids by P III/P V═O Catalysis. J Am Chem Soc 2018; 140:15200-15205. [PMID: 30372615 DOI: 10.1021/jacs.8b10769] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A main group-catalyzed method for the synthesis of aryl- and heteroarylamines by intermolecular C-N coupling is reported. The method employs a small-ring organophosphorus-based catalyst (1,2,2,3,4,4-hexamethylphosphetane) and a terminal hydrosilane reductant (phenylsilane) to drive reductive intermolecular coupling of nitro(hetero)arenes with boronic acids. Applications to the construction of both Csp2-N (from arylboronic acids) and Csp3-N bonds (from alkylboronic acids) are demonstrated; the reaction is stereospecific with respect to Csp3-N bond formation. The method constitutes a new route from readily available building blocks to valuable nitrogen-containing products with complementarity in both scope and chemoselectivity to existing catalytic C-N coupling methods.
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Affiliation(s)
- Trevor V Nykaza
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Julian C Cooper
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Gen Li
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Nolwenn Mahieu
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Antonio Ramirez
- Chemical and Synthetic Development , Bristol-Myers Squibb Company , One Squibb Drive , New Brunswick , New Jersey 08903 , United States
| | - Michael R Luzung
- Chemical and Synthetic Development , Bristol-Myers Squibb Company , One Squibb Drive , New Brunswick , New Jersey 08903 , United States
| | - Alexander T Radosevich
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
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76
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77
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Abstract
The hallmark of nucleophilic phosphine catalysis is the initial nucleophilic addition of a phosphine to an electrophilic starting material, producing a reactive zwitterionic intermediate, generally under mild conditions. In this Review, we classify nucleophilic phosphine catalysis reactions in terms of their electrophilic components. In the majority of cases, these electrophiles possess carbon-carbon multiple bonds: alkenes (section 2), allenes (section 3), alkynes (section 4), and Morita-Baylis-Hillman (MBH) alcohol derivatives (MBHADs; section 5). Within each of these sections, the reactions are compiled based on the nature of the second starting material-nucleophiles, dinucleophiles, electrophiles, and electrophile-nucleophiles. Nucleophilic phosphine catalysis reactions that occur via the initial addition to starting materials that do not possess carbon-carbon multiple bonds are collated in section 6. Although not catalytic in the phosphine, the formation of ylides through the nucleophilic addition of phosphines to carbon-carbon multiple bond-containing compounds is intimately related to the catalysis and is discussed in section 7. Finally, section 8 compiles miscellaneous topics, including annulations of the Hüisgen zwitterion, phosphine-mediated reductions, iminophosphorane organocatalysis, and catalytic variants of classical phosphine oxide-generating reactions.
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Affiliation(s)
- Hongchao Guo
- Department of Applied Chemistry, China Agricultural University, Beijing 100193, P. R. China
| | - Yi Chiao Fan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, CA 90095-1569, USA
| | - Zhanhu Sun
- Department of Applied Chemistry, China Agricultural University, Beijing 100193, P. R. China
| | - Yang Wu
- Department of Applied Chemistry, China Agricultural University, Beijing 100193, P. R. China
| | - Ohyun Kwon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, CA 90095-1569, USA
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78
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Yang M, Tofan D, Chen CH, Jack KM, Gabbaï FP. Digging the Sigma-Hole of Organoantimony Lewis Acids by Oxidation. Angew Chem Int Ed Engl 2018; 57:13868-13872. [PMID: 30151881 DOI: 10.1002/anie.201808551] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Indexed: 12/14/2022]
Abstract
The development of group 15 Lewis acids is an area of active investigation that has led to numerous advances in anion sensing and catalysis. While phosphorus has drawn considerable attention, emerging research shows that organoantimony(III) reagents may also act as potent Lewis acids. Comparison of the properties of SbPh3 , Sb(C6 F5 )3 , and SbArF 3 with those of their tetrachlorocatecholate analogues SbPh3 Cat, Sb(C6 F5 )3 Cat, and SbArF 3 Cat (Cat=o-O2 C6 Cl4 , ArF =3,5-(CF3 )2 C6 H3 ) demonstrates that the Lewis acidity of electron deficient organoantimony(III) reagents can be readily enhanced by oxidation to the +V state-as verified by binding studies, organic reaction catalysis, and computational studies. The results are rationalized by explaining that oxidation of the antimony center leads to a lowering of the accepting σ* orbital and a deeper carving of the associated σ-hole.
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Affiliation(s)
- Mengxi Yang
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Daniel Tofan
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Chang-Hong Chen
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Kevin M Jack
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - François P Gabbaï
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
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79
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Yang M, Tofan D, Chen C, Jack KM, Gabbaï FP. Digging the Sigma‐Hole of Organoantimony Lewis Acids by Oxidation. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201808551] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Mengxi Yang
- Department of ChemistryTexas A&M University College Station TX 77843 USA
| | - Daniel Tofan
- Department of ChemistryTexas A&M University College Station TX 77843 USA
| | - Chang‐Hong Chen
- Department of ChemistryTexas A&M University College Station TX 77843 USA
| | - Kevin M. Jack
- Department of ChemistryTexas A&M University College Station TX 77843 USA
| | - François P. Gabbaï
- Department of ChemistryTexas A&M University College Station TX 77843 USA
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80
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Nishimura K, Unoh Y, Hirano K, Miura M. Phosphenium-Cation-Mediated Formal Cycloaddition Approach to Benzophospholes. Chemistry 2018; 24:13089-13092. [DOI: 10.1002/chem.201803225] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/19/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Kazutoshi Nishimura
- Department of Applied Chemistry; Graduate School of Engineering; Osaka University; Suita Osaka 565-0871 Japan
| | - Yuto Unoh
- Department of Applied Chemistry; Graduate School of Engineering; Osaka University; Suita Osaka 565-0871 Japan
| | - Koji Hirano
- Department of Applied Chemistry; Graduate School of Engineering; Osaka University; Suita Osaka 565-0871 Japan
| | - Masahiro Miura
- Department of Applied Chemistry; Graduate School of Engineering; Osaka University; Suita Osaka 565-0871 Japan
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81
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Kyri AW, Gleim F, García Alcaraz A, Schnakenburg G, Espinosa Ferao A, Streubel R. "Low-coordinate" 1,2-oxaphosphetanes - a new opportunity in coordination and main group chemistry. Chem Commun (Camb) 2018; 54:7123-7126. [PMID: 29770833 DOI: 10.1039/c8cc02963f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
While 1,2σ5λ5-oxaphosphetanes are well known intermediates from the Wittig-reaction, no 1,2σ3λ3-oxaphosphetanes have been described, so far. Herein, we present the first synthesis of 1,2σ3λ3-oxaphosphetanes derived from their κP-Mo(CO)5 complexes and first investigations towards metal coordination and P-oxidation. Bonding, ring strain energy and potential retro-[2+2] cycloaddition reactions of the 1,2-oxaphosphetane ring were studied by DFT methods.
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Affiliation(s)
- A W Kyri
- Institut für Anorganische Chemie der, Rheinischen Friedrich-Wilhelms-Universität Bonn, Gerhardt-Domagk-Straße 1, 53121 Bonn, Germany.
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82
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Zhou R, Zhang H, Liu J, Liu R, Gao WC, Qiao Y, Li R. Chemoselective P(NMe 2) 3-Mediated Reductive Epoxidation between Two Different Carbonyl Electrophiles: Synthesis of Highly Functionalized Unsymmetrical Epoxides. J Org Chem 2018; 83:8272-8280. [PMID: 29870246 DOI: 10.1021/acs.joc.8b00995] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Herein, we report a chemoselective P(NMe2)3-mediated reductive epoxidation of α-dicarbonyl compounds such as isatins, α-keto esters, and α-diketones with aldehydes and ketones, leading to an efficient synthesis of a wide range of highly functionalized unsymmetrical epoxides in moderate to excellent yields and diastereoselectivities. The Kukhtin-Ramirez adduct, which is exclusively generated in situ from an α-dicarbonyl compound and P(NMe2)3, plays a key role in governing the chemoselectivity. It represents the first practical synthesis of unsymmetrical epoxides via direct reductive epoxidation of two different carbonyl electrophiles and also complements the existing methods of generating epoxides.
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Affiliation(s)
- Rong Zhou
- College of Chemistry and Chemical Engineering , Taiyuan University of Technology , Taiyuan 030024 , P. R. China
| | - Honghui Zhang
- College of Chemistry and Chemical Engineering , Taiyuan University of Technology , Taiyuan 030024 , P. R. China
| | - Jialin Liu
- College of Chemistry and Chemical Engineering , Taiyuan University of Technology , Taiyuan 030024 , P. R. China
| | - Rongfang Liu
- College of Chemistry and Chemical Engineering , Taiyuan University of Technology , Taiyuan 030024 , P. R. China
| | - Wen-Chao Gao
- College of Chemistry and Chemical Engineering , Taiyuan University of Technology , Taiyuan 030024 , P. R. China
| | - Yan Qiao
- The State Key Laboratory of Coal Conversion, Institute of Coal Chemistry , Chinese Academy of Sciences , Taiyuan 030001 , P. R. China
| | - Ruifeng Li
- College of Chemistry and Chemical Engineering , Taiyuan University of Technology , Taiyuan 030024 , P. R. China
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83
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Schoene J, Bel Abed H, Schmieder P, Christmann M, Nazaré M. A General One-Pot Synthesis of 2H-Indazoles Using an Organophosphorus-Silane System. Chemistry 2018; 24:9090-9100. [PMID: 29644761 DOI: 10.1002/chem.201800763] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Indexed: 11/11/2022]
Abstract
A simple and direct approach for the regioselective construction of the privileged 2H-indazole scaffold is described. The developed one-pot strategy involves phospholene-mediated N-N bond formation to access 2H-indazoles. The amount of organophosphorus reagent was minimized by recycling the phospholene oxide with organosilane reductants. Starting from functionalized 2-nitrobenzaldehydes and primary amines, a mild reductive cyclization, involving the use of commercially available phospholene oxide and silanes, delivered a wide variety of substituted 2H-indazoles in good to excellent yields.
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Affiliation(s)
- Jens Schoene
- Departments of Chemical Biology and Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125, Berlin, Germany
| | - Hassen Bel Abed
- Departments of Chemical Biology and Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125, Berlin, Germany
| | - Peter Schmieder
- Departments of Chemical Biology and Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125, Berlin, Germany
| | - Mathias Christmann
- Institut für Chemie und Biochemie, Organische Chemie, Freie Universität Berlin, Takustrasse. 3, 14195, Berlin, Germany
| | - Marc Nazaré
- Departments of Chemical Biology and Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125, Berlin, Germany.,Berlin Institute of Health (BIH), Anna-Louisa-Karsch-Str. 2, 10178 Kapelle-Ufer 2, 10117, Berlin, Germany
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84
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Eckert KE, Ashfeld BL. Aroyl Isocyanates as 1,4-Dipoles in a Formal [4 + 1]-Cycloaddition Approach toward Oxazolone Construction. Org Lett 2018; 20:2315-2319. [DOI: 10.1021/acs.orglett.8b00656] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Kaitlyn E. Eckert
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Brandon L. Ashfeld
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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85
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Feng J, Ma PJ, Zeng YM, Xu YJ, Lu CD. Construction of α-methoxyimidoyl ketonitrones via phosphite-mediated addition of α-keto N-tert-butanesulfinyl imidates to nitrosoarenes. Chem Commun (Camb) 2018; 54:2882-2885. [PMID: 29493693 DOI: 10.1039/c8cc00345a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A dimethyl phosphite-mediated addition of α-keto N-tert-butanesulfinyl imidates to nitrosoarenes was developed. Nitrosoarenes were successfully used as electrophiles to trap aza-enolate intermediates that were generated from nucleophilic addition of deprotonated phosphite to α-keto N-tert-butanesulfinyl imidates and following phospha-Brook rearrangement, allowing efficient construction of ketonitrones with excellent (Z)-geometries.
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Affiliation(s)
- Jie Feng
- Department of Chemistry and Applied Chemistry, Changji University, Changji 831100, China.
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86
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Zhang K, Cai L, Yang Z, Houk KN, Kwon O. Bridged [2.2.1] bicyclic phosphine oxide facilitates catalytic γ-umpolung addition-Wittig olefination. Chem Sci 2018; 9:1867-1872. [PMID: 29732112 PMCID: PMC5909331 DOI: 10.1039/c7sc04381c] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/02/2018] [Indexed: 12/13/2022] Open
Abstract
A novel bridged [2.2.1] bicyclic phosphine oxide, devised to circumvent the waste generation and burdens of purification that are typical of reactions driven by the generation of phosphine oxides, has been prepared in three steps from commercially available cyclopent-3-ene-1-carboxylic acid. The performance of this novel phosphine oxide was superior to those of current best-in-class counterparts, as verified experimentally through kinetic analysis of its silane-mediated reduction. It has been applied successfully in halide-/base-free catalytic γ-umpolung addition-Wittig olefinations of allenoates and 2-amidobenzaldehydes to produce 1,2-dihydroquinolines with good efficiency. One of the 1,2-dihydroquinoline products was converted to known antitubercular furanoquinolines.
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Affiliation(s)
- Kui Zhang
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095-1569 , USA .
| | - Lingchao Cai
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095-1569 , USA .
| | - Zhongyue Yang
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095-1569 , USA .
| | - K N Houk
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095-1569 , USA .
| | - Ohyun Kwon
- Department of Chemistry and Biochemistry , University of California , Los Angeles , California 90095-1569 , USA .
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87
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Nykaza TV, Ramirez A, Harrison TS, Luzung MR, Radosevich AT. Biphilic Organophosphorus-Catalyzed Intramolecular C sp2-H Amination: Evidence for a Nitrenoid in Catalytic Cadogan Cyclizations. J Am Chem Soc 2018; 140:3103-3113. [PMID: 29389114 DOI: 10.1021/jacs.7b13803] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A small-ring phosphacycloalkane (1,2,2,3,4,4-hexamethylphosphetane, 3) catalyzes intramolecular C-N bond forming heterocyclization of o-nitrobiaryl and -styrenyl derivatives in the presence of a hydrosilane terminal reductant. The method provides scalable access to diverse carbazole and indole compounds under operationally trivial homogeneous organocatalytic conditions, as demonstrated by 17 examples conducted on 1 g scale. In situ NMR reaction monitoring studies support a mechanism involving catalytic PIII/PV═O cycling, where tricoordinate phosphorus compound 3 represents the catalytic resting state. For the catalytic conversion of o-nitrobiphenyl to carbazole, the kinetic reaction order was determined for phosphetane catalyst 3 (first order), substrate (first order), and phenylsilane (zeroth order). For differentially 5-substituted 2-nitrobiphenyls, the transformation is accelerated by electron-withdrawing substituents (Hammett factor ρ = +1.5), consistent with the accrual of negative charge on the nitro substrate in the rate-determining step. DFT modeling of the turnover-limiting deoxygenation event implicates a rate-determining (3 + 1) cheletropic addition between the phosphetane catalyst 3 and 2-nitrobiphenyl substrate to form an unobserved pentacoordinate spiro-bicyclic dioxazaphosphetane, which decomposes via (2 + 2) cycloreversion giving 1 equiv of phosphetane P-oxide 3·[O] and 2-nitrosobiphenyl. Experimental and computational investigations into the C-N bond forming event suggest the involvement of an oxazaphosphirane (2 + 1) adduct between 3 and 2-nitrosobiphenyl, which evolves through loss of phosphetane P-oxide 3·[O] to give the observed carbazole product via C-H insertion in a nitrene-like fashion.
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Affiliation(s)
- Trevor V Nykaza
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Antonio Ramirez
- Chemical and Synthetic Development, Bristol-Myers Squibb Company , One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Tyler S Harrison
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Michael R Luzung
- Chemical and Synthetic Development, Bristol-Myers Squibb Company , One Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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88
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Zhang H, Liu R, Liu J, Fan B, Li R, Qiao Y, Zhou R. Chemoselective phosphine-catalyzed cyanoacylation of α-dicarbonyl compounds: a general method for the synthesis of cyanohydrin esters with one quaternary stereocenter. NEW J CHEM 2018. [DOI: 10.1039/c8nj04867c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A chemoselective phosphine-catalyzed cyanoacylation of α-dicarbonyl compounds with acyl cyanides is reported.
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Affiliation(s)
- Honghui Zhang
- College of Chemistry and Chemical Engineering
- Taiyuan University of Technology
- Taiyuan
- P. R. China
| | - Rongfang Liu
- College of Chemistry and Chemical Engineering
- Taiyuan University of Technology
- Taiyuan
- P. R. China
| | - Jialin Liu
- College of Chemistry and Chemical Engineering
- Taiyuan University of Technology
- Taiyuan
- P. R. China
| | - Binbin Fan
- College of Chemistry and Chemical Engineering
- Taiyuan University of Technology
- Taiyuan
- P. R. China
| | - Ruifeng Li
- College of Chemistry and Chemical Engineering
- Taiyuan University of Technology
- Taiyuan
- P. R. China
| | - Yan Qiao
- The State Key Laboratory of Coal Conversion
- Institute of Coal Chemistry
- Chinese Academy of Sciences
- Taiyuan
- P. R. China
| | - Rong Zhou
- College of Chemistry and Chemical Engineering
- Taiyuan University of Technology
- Taiyuan
- P. R. China
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89
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Taylor LJ, Bühl M, Chalmers BA, Ray MJ, Wawrzyniak P, Walton JC, Cordes DB, Slawin AMZ, Woollins JD, Kilian P. Dealkanative Main Group Couplings across the peri-Gap. J Am Chem Soc 2017; 139:18545-18551. [PMID: 29191021 DOI: 10.1021/jacs.7b08682] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Here, we highlight the ability of peri-substitution chemistry to promote a series of unique P-P/P-As coupling reactions, which proceed with concomitant C-H bond formation. This dealkanative reactivity represents an interesting and unexpected expansion to the established family of main-group dehydrocoupling reactions. These transformations are exceptionally clean, proceeding essentially quantitatively at relatively low temperatures (70-140 °C), with 100% diastereoselectivity in the products. The reaction appears to be radical in nature, with the addition of small quantities of a radical initiator (azobis(isobutyronitrile)) increasing the rate dramatically, as well as altering the apparent order of reaction. DFT calculations suggest that the reaction involves dissociation of a phosphorus centered radical (stabilized by the peri-backbone) to the P-P coupled product and a free propyl radical, which carries the chain. This unusual reaction demonstrates the powerful effect that geometric constraints, in this case a rigid scaffold, can have on the reactivity of main group species, an area of research that is gaining increasing prominence in recent years.
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Affiliation(s)
- Laurence J Taylor
- University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland
| | - Michael Bühl
- University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland
| | - Brian A Chalmers
- University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland
| | - Matthew J Ray
- University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland
| | - Piotr Wawrzyniak
- University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland
| | - John C Walton
- University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland
| | - David B Cordes
- University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland
| | - Alexandra M Z Slawin
- University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland
| | - J Derek Woollins
- University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland
| | - Petr Kilian
- University of St Andrews , School of Chemistry, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom of Great Britain and Northern Ireland
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90
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Buonomo JA, Eiden CG, Aldrich CC. Chemoselective Reduction of Phosphine Oxides by 1,3-Diphenyl-Disiloxane. Chemistry 2017; 23:14434-14438. [PMID: 28840623 PMCID: PMC5647249 DOI: 10.1002/chem.201703875] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Indexed: 11/09/2022]
Abstract
Reduction of phosphine oxides to the corresponding phosphines represents the most straightforward method to prepare these valuable reagents. However, existing methods to reduce phosphine oxides suffer from inadequate chemoselectivity due to the strength of the P=O bond and/or poor atom economy. Herein, we report the discovery of the most powerful chemoselective reductant for this transformation to date, 1,3-diphenyl-disiloxane (DPDS). Additive-free DPDS selectively reduces both secondary and tertiary phosphine oxides with retention of configuration even in the presence of aldehyde, nitro, ester, α,β-unsaturated carbonyls, azocarboxylates, and cyano functional groups. Arrhenius analysis indicates that the activation barrier for reduction by DPDS is significantly lower than any previously calculated silane reduction system. Inclusion of a catalytic Brønsted acid further reduced the activation barrier and led to the first silane-mediated reduction of acyclic phosphine oxides at room temperature.
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Affiliation(s)
- Joseph A Buonomo
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard St. SE, Minneapolis, MN, 55455, USA
| | - Carter G Eiden
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard St. SE, Minneapolis, MN, 55455, USA
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard St. SE, Minneapolis, MN, 55455, USA
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91
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Liu Y, Li H, Zhou X, He Z. P(NMe2)3-Mediated Reductive (1 + 4) Annulation Reaction of Isatins with Nitroalkenes: An Access to Spirooxindolyl Isoxazoline N-Oxides and Their Corresponding Isoxazolines. J Org Chem 2017; 82:10997-11007. [DOI: 10.1021/acs.joc.7b01962] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yiyi Liu
- The
State Key Laboratory of Elemento-Organic Chemistry and Collaborative
Innovation Center of Chemical Science and Engineering (Tianjin), College
of Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Hengyu Li
- The
State Key Laboratory of Elemento-Organic Chemistry and Collaborative
Innovation Center of Chemical Science and Engineering (Tianjin), College
of Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Xun Zhou
- School
of Materials Science and Engineering, Central South University, Changsha 410083, P. R. China
| | - Zhengjie He
- The
State Key Laboratory of Elemento-Organic Chemistry and Collaborative
Innovation Center of Chemical Science and Engineering (Tianjin), College
of Chemistry, Nankai University, Tianjin 300071, P. R. China
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92
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Batesky DC, Goldfogel MJ, Weix DJ. Removal of Triphenylphosphine Oxide by Precipitation with Zinc Chloride in Polar Solvents. J Org Chem 2017; 82:9931-9936. [PMID: 28956444 PMCID: PMC5634519 DOI: 10.1021/acs.joc.7b00459] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
While the use of triphenylphosphine as a reductant is common in organic synthesis, the resulting triphenylphosphine oxide (TPPO) waste can be difficult to separate from the reaction product. While a number of strategies to precipitate TPPO are available, none have been reported to work in more polar solvents. We report here that mixing ZnCl2 with TPPO precipitates a TPPO-Zn complex in high yield in several common polar organic solvents. The solvent compatibility of this procedure and the reliability of the precipitation in the presence of polar functional groups were examined to show the utility and limitations of this method.
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Affiliation(s)
- Donald C Batesky
- Department of Chemistry, University of Rochester , Rochester, New York 14627-0216, United States and
| | - Matthew J Goldfogel
- Department of Chemistry, University of Wisconsin , Madison, Wisconsin 53706, United States
| | - Daniel J Weix
- Department of Chemistry, University of Wisconsin , Madison, Wisconsin 53706, United States
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93
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Buonomo JA, Eiden CG, Aldrich CC. Scalable Synthesis of Hydrido-Disiloxanes from Silanes: A One-Pot Preparation of 1,3-Diphenyldisiloxane from Phenylsilane. SYNTHESIS-STUTTGART 2017; 50:278-281. [PMID: 29662252 DOI: 10.1055/s-0036-1588580] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A simple, one-pot, and high-yielding synthesis of 1,3-diphenyldisiloxane is presented. The preparation of similar symmetrical disiloxane materials is also accomplished with this same protocol. This mechano-chemical procedure is efficient and highly scalable, furnishing a convenient route to hydrido-disiloxanes from widely accessible commercially available silanes.
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Affiliation(s)
- Joseph A Buonomo
- University of Minnesota, Department of Medicinal Chemistry, Weaver-Densford Hall, 308 Harvard St. SE Minneapolis, MN 55455, USA
| | - Carter G Eiden
- University of Minnesota, Department of Medicinal Chemistry, Weaver-Densford Hall, 308 Harvard St. SE Minneapolis, MN 55455, USA
| | - Courtney C Aldrich
- University of Minnesota, Department of Medicinal Chemistry, Weaver-Densford Hall, 308 Harvard St. SE Minneapolis, MN 55455, USA
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94
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Saleh N, Blanchard F, Voituriez A. Synthesis of Nitrogen-Containing Heterocycles and Cyclopentenone Derivatives via
Phosphine-Catalyzed Michael Addition/Intramolecular Wittig Reaction. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201700313] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Nidal Saleh
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Sud; Université Paris-Saclay; 1 av. de la Terrasse 91198 Gif-sur-Yvette France
| | - Florent Blanchard
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Sud; Université Paris-Saclay; 1 av. de la Terrasse 91198 Gif-sur-Yvette France
| | - Arnaud Voituriez
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Sud; Université Paris-Saclay; 1 av. de la Terrasse 91198 Gif-sur-Yvette France
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95
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Zhang L, Lu H, Xu GQ, Wang ZY, Xu PF. PPh3 Mediated Reductive Annulation Reaction between Isatins and Electron Deficient Dienes to Construct Spirooxindole Compounds. J Org Chem 2017; 82:5782-5789. [DOI: 10.1021/acs.joc.7b00595] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Lei Zhang
- State Key Laboratory of Applied
Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - Hong Lu
- State Key Laboratory of Applied
Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - Guo-Qiang Xu
- State Key Laboratory of Applied
Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - Zhu-Yin Wang
- State Key Laboratory of Applied
Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - Peng-Fei Xu
- State Key Laboratory of Applied
Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
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96
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Nykaza TV, Harrison TS, Ghosh A, Putnik RA, Radosevich AT. A Biphilic Phosphetane Catalyzes N-N Bond-Forming Cadogan Heterocyclization via P III/P V═O Redox Cycling. J Am Chem Soc 2017; 139:6839-6842. [PMID: 28489354 DOI: 10.1021/jacs.7b03260] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A small-ring phosphacycle, 1,2,2,3,4,4-hexamethylphosphetane, is found to catalyze deoxygenative N-N bond-forming Cadogan heterocyclization of o-nitrobenzaldimines, o-nitroazobenzenes, and related substrates in the presence of hydrosilane terminal reductant. The reaction provides a chemoselective catalytic synthesis of 2H-indazoles, 2H-benzotriazoles, and related fused heterocyclic systems with good functional group compatibility. On the basis of both stoichiometric and catalytic mechanistic experiments, the reaction is proposed to proceed via catalytic PIII/PV═O cycling, where DFT modeling suggests a turnover-limiting (3+1) cheletropic addition between the phosphetane catalyst and nitroarene substrate. Strain/distortion analysis of the (3+1) transition structure highlights the controlling role of frontier orbital effects underpinning the catalytic performance of the phosphetane.
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Affiliation(s)
- Trevor V Nykaza
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Tyler S Harrison
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Avipsa Ghosh
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Rachel A Putnik
- Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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97
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Geibel I, Dierks A, Müller T, Christoffers J. Formation of δ-Lactones with anti-Baeyer-Villiger Regiochemistry: Investigations into the Mechanism of the Cerium-Catalyzed Aerobic Coupling of β-Oxoesters with Enol Acetates. Chemistry 2017; 23:7245-7254. [PMID: 28230284 DOI: 10.1002/chem.201605468] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/03/2017] [Indexed: 11/06/2022]
Abstract
The cerium-catalyzed, aerobic coupling of β-oxoesters with enol acetates and dioxygen yields δ-lactones with a 1,4-diketone moiety. In contrast to the Baeyer-Villiger oxidation (BVO), where the higher substituted residue migrates; in the case of this oxidative C-C coupling reaction, the less substituted alkyl residue undergoes a 1,2-shift. An endoperoxidic oxycarbenium ion comparable to the Criegee intermediate in the BVO is proposed as a reaction intermediate and submitted to conformational analysis by computational methods. As a result, the inverse regiochemistry is explained by a primary stereoelectronic effect. A Hammett analysis using different donor- and acceptor-substituted enol esters provides support for the oxycarbenium ion being the crucial intermediate in the rate determining step of the conversion. An overall mechanism is suggested with a radical chain reaction for the formation of endoperoxides from β-oxoesters, enol acetates and dioxygen with a cerium(IV) species as initiating reagent.
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Affiliation(s)
- Irina Geibel
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, 26111, Oldenburg, Germany
| | - Anna Dierks
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, 26111, Oldenburg, Germany
| | - Thomas Müller
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, 26111, Oldenburg, Germany
| | - Jens Christoffers
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, 26111, Oldenburg, Germany
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98
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Andrews KG, Denton RM. A more critical role for silicon in the catalytic Staudinger amidation: silanes as non-innocent reductants. Chem Commun (Camb) 2017; 53:7982-7985. [DOI: 10.1039/c7cc03076b] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We demonstrate that in situ-generated silyl ester intermediates are key mediators of the catalytic, traceless Staudinger amidation reaction.
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99
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Guo S, Dai Z, Hua J, Yang Z, Fang Z, Guo K. Microfluidic synthesis of α-ketoesters via oxidative coupling of acetophenones with alcohols under metal-free conditions. REACT CHEM ENG 2017. [DOI: 10.1039/c7re00107j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
An efficient and novel method for the synthesis of α-ketoesters has been developed via oxidative coupling of acetophenones with alcohols under TBHP/I2/DBU conditions in a microfluidic chip reactor, which has a wide substrate scope, uses a lower dosage of iodine and affords higher product yields in only a few seconds.
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Affiliation(s)
- Shiyu Guo
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing
- China
| | - Zhongxue Dai
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing
- China
| | - Jiawei Hua
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing
- China
| | - Zhao Yang
- College of Engineering
- China Pharmaceutical University
- Nanjing
- China
| | - Zheng Fang
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing
- China
| | - Kai Guo
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing
- China
- State Key Laboratory of Materials-Oriented Chemical Engineering
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100
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Hamstra DFJ, Lenstra DC, Koenders TJ, Rutjes FPJT, Mecinović J. Poly(methylhydrosiloxane) as a green reducing agent in organophosphorus-catalysed amide bond formation. Org Biomol Chem 2017; 15:6426-6432. [DOI: 10.1039/c7ob01510k] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In situ reduction of phosphine oxide by poly(methylhydrosiloxane) leads to efficient amidation reaction between carboxylic acids and amines.
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Affiliation(s)
- Daan F. J. Hamstra
- Institute for Molecules and Materials
- Radboud University
- 6525 AJ Nijmegen
- The Netherlands
| | - Danny C. Lenstra
- Institute for Molecules and Materials
- Radboud University
- 6525 AJ Nijmegen
- The Netherlands
| | - Tjeu J. Koenders
- Institute for Molecules and Materials
- Radboud University
- 6525 AJ Nijmegen
- The Netherlands
| | | | - Jasmin Mecinović
- Institute for Molecules and Materials
- Radboud University
- 6525 AJ Nijmegen
- The Netherlands
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