1
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Zhang G, Wodrich MD, Cramer N. Catalytic enantioselective reductive Eschenmoser-Claisen rearrangements. Science 2024; 383:395-401. [PMID: 38271525 DOI: 10.1126/science.adl3369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 12/19/2023] [Indexed: 01/27/2024]
Abstract
An important challenge in enantioselective catalysis is developing strategies for the precise synthesis of neighboring congested all-carbon quaternary stereocenters. The well-defined transition states of [3,3]-sigmatropic rearrangements and their underlying stereospecificity render them powerful tools for the synthesis of such arrays. However, this type of pericyclic reaction remains notoriously difficult to catalyze, especially in an enantioselective fashion. Herein, we describe an enantioselective reductive Eschenmoser-Claisen rearrangement catalyzed by chiral 1,3,2-diazaphospholene-hydrides. This developed transformation enables full control of the two newly formed acyclic stereogenic centers, leading to amides with vicinal all-carbon quaternary-tertiary or quaternary-quaternary carbon atoms.
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Affiliation(s)
- Guoting Zhang
- Laboratory of Asymmetric Catalysis and Synthesis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Matthew D Wodrich
- Laboratory for Computational Molecular Design, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Nicolai Cramer
- Laboratory of Asymmetric Catalysis and Synthesis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
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2
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Zhang G, Cramer N. Reductive Asymmetric Aza-Mislow-Evans Rearrangement by 1,3,2-Diazaphospholene Catalysis. Angew Chem Int Ed Engl 2023; 62:e202301076. [PMID: 36820495 DOI: 10.1002/anie.202301076] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 02/24/2023]
Abstract
1,3,2-diazaphospholene hydrides (DAP-H) enable smooth conjugate reduction of polarized double bonds. The transiently formed phosphorus-enolate provides a potential platform for reductive α-functionalizations. In this respect, asymmetric C-heteroatom bond forming processes are synthetically appealing but remain elusive. We report a 1,3,2-diazaphospholene-catalyzed three-step cascade reaction of N-sulfinyl acrylamides comprised of conjugate reduction, [2,3]-sigmatropic aza-Mislow-Evans rearrangement and subsequent S-O bond cleavage. The obtained enantio-enriched α-hydroxy amides are formed in good yields and excellent enantiospecificity. The stereo-defined P-bound N,O-ketene aminal ensures an excellent transfer of chirality from the sulfur stereocenter to α-carbon. The transformation operates under mild conditions at ambient temperature. Moreover, DAP-H is a competent reductant for the cleavage of formed sulfenate ester, eliminating the extra step in traditional Mislow-Evans processes.
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Affiliation(s)
- Guoting Zhang
- Institute of Chemical Sciences and Engineering (ISIC), EPFL SB ISIC LCSA, BCH 4305, 1015, Lausanne, Switzerland
| | - Nicolai Cramer
- Institute of Chemical Sciences and Engineering (ISIC), EPFL SB ISIC LCSA, BCH 4305, 1015, Lausanne, Switzerland
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3
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De Oliveira Silva A, Harper JL, Fuhr KN, Lalancette RA, Cheong PHY, Brenner-Moyer SE. DyKAT by DiCat: Stereoconvergent Dienamine-Catalyzed Claisen Rearrangements. J Org Chem 2022; 87:10105-10113. [PMID: 35881006 DOI: 10.1021/acs.joc.2c01079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This Claisen rearrangement establishes the feasibility of DyKAT of γ-epimeric enals via dienamine formation to afford enantioenriched products. γ-Aryl and -alkyl enals, and exocyclic enals that introduce quaternary centers, are all amenable substrates. Products are readily converted into pyrrolidines or cyclopentenols. Notably, a reactive dienamine intermediate has been isolated from a catalytic reaction, fully characterized, and converted to product upon reexposure to reaction conditions. Product configuration arises from a directing C-H···π interaction in the transition state.
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Affiliation(s)
- Ana De Oliveira Silva
- Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, New Jersey 07102, United States
| | - Jordan L Harper
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Katherine N Fuhr
- Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, New Jersey 07102, United States
| | - Roger A Lalancette
- Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, New Jersey 07102, United States
| | - Paul Ha-Yeon Cheong
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Stacey E Brenner-Moyer
- Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, New Jersey 07102, United States
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4
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Abstract
Carbon–carbon bond formation by [3,3]-sigmatropic rearrangement is a fundamental and powerful method that has been used to build organic molecules for a long time. Initially, Claisen and Cope rearrangements proceeded at high temperatures with limited scopes. By introducing catalytic systems, highly functionalized substrates have become accessible for forming complex structures under mild conditions, and asymmetric synthesis can be achieved by using chiral catalytic systems. This review describes recent breakthroughs in catalytic [3,3]-sigmatropic rearrangements since 2016. Detailed reaction mechanisms are discussed to enable an understanding of the reactivity and selectivity of the reactions. Finally, this review is inspires the development of new cascade reaction pathways employing catalytic [3,3]-sigmatropic rearrangement as related methodologies for the synthesis of complex functional molecules.
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5
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Zhang YS, Huan Z, Yang JD, Cheng JP. Synthetic applications of NHPs: from the hydride pathway to a radical mechanism. Chem Commun (Camb) 2022; 58:12528-12543. [DOI: 10.1039/d2cc04844b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We briefly summarized synthetic applications of N-heterocyclic phosphines in both hydridic and radical reductions with an emphasis on their recently discovered radical reactivity.
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Affiliation(s)
- Yu-Shan Zhang
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Zhen Huan
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Jin-Dong Yang
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Jin-Pei Cheng
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China
- State Key Laboratory of Elemento-organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
- Haihe Laboratory of Sustainable Chemical Transformations, Keyan West Road, Tianjin, 300192, China
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6
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Niu R, He Y, Lin JB. Catalytic asymmetric synthesis of α-stereogenic carboxylic acids: recent advances. Org Biomol Chem 2021; 20:37-54. [PMID: 34854454 DOI: 10.1039/d1ob02038b] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Chiral carboxylic acids bearing an α-stereogenic center constitute the backbone of many natural products and therapeutic reagents as well as privileged chiral ligands and catalysts. Hence, it is not surprising that a large number of elegant catalytic asymmetric strategies have been developed toward the efficient synthesis of α-chiral carboxylic acids, such as α-hydroxy acids and α-amino acids. In this review, the recent advances in asymmetric synthesis of α-stereogenic free carboxylic acids via organocatalysis and transition metal catalysis are summarized (mainly from 2010 to 2020). The content is organized by the reaction type of the carboxyl source involved, including asymmetric functionalization of substituted carboxylic acids, cyclic anhydrides, α-keto acids, substituted α,β-unsaturated acids and so on. We hope that this review will motivate further interest in catalytic asymmetric synthesis of chiral α-substituted carboxylic acids.
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Affiliation(s)
- Rui Niu
- Shaanxi Key Laboratory of Chemical Reaction Engineering, College of Chemistry and Chemical Engineering, Yan'an University, Yan'an 716000, China.
| | - Yi He
- Shaanxi Key Laboratory of Chemical Reaction Engineering, College of Chemistry and Chemical Engineering, Yan'an University, Yan'an 716000, China.
| | - Jun-Bing Lin
- Shaanxi Key Laboratory of Chemical Reaction Engineering, College of Chemistry and Chemical Engineering, Yan'an University, Yan'an 716000, China.
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7
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Zhang J, Zhao X, Yang JD, Cheng JP. Diazaphospholene-Catalyzed Hydrodefluorination of Polyfluoroarenes with Phenylsilane via Concerted Nucleophilic Aromatic Substitution. J Org Chem 2021; 87:294-300. [PMID: 34933552 DOI: 10.1021/acs.joc.1c02360] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The metal-free catalytic C-F bond activation of polyfluoroarenes was achieved with diazaphospholene as the catalyst and phenylsilane as the terminal reductant. Density functional theory calculations suggested a concerted nucleophilic aromatic substitution mechanism.
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Affiliation(s)
- Jingjing Zhang
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Xiao Zhao
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Jin-Dong Yang
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Jin-Pei Cheng
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing 100084, China.,State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
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8
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Guo S, Wong KC, Scheeff S, He Z, Chan WTK, Low KH, Chiu P. Copper-Catalyzed Reductive Ireland-Claisen Rearrangements of Propargylic Acrylates and Allylic Allenoates. J Org Chem 2021; 87:429-452. [PMID: 34918517 DOI: 10.1021/acs.joc.1c02455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The copper-catalyzed reductive Ireland-Claisen rearrangement of propargylic acrylates led to 3,4-allenoic acids. The use of silanes or pinacolborane as stoichiometric reducing agents and triethylphosphite as a ligand facilitated the divergent and complementary selectivity for the synthesis of diastereomeric anti- and syn-rearranged products, respectively. Copper-catalyzed reductive Ireland-Claisen rearrangement of allylic 2,3-allenoates proceeded effectively only when pinacolborane was used as a reductant to generate various 1,5-dienes in excellent yields and with good diastereoselectivities in some cases. Mechanistic studies showed that the silyl and boron enolates, rather than the copper enolate, underwent a stereospecific rearrangement via a chairlike transition state to afford the corresponding Claisen rearrangement products.
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Affiliation(s)
- Siyuan Guo
- Department of Chemistry and The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Kong Ching Wong
- Department of Chemistry and The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Stephan Scheeff
- Department of Chemistry and The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Zhuo He
- Department of Chemistry and The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Wesley Ting Kwok Chan
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, P. R. China
| | - Kam-Hung Low
- Department of Chemistry and The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Pauline Chiu
- Department of Chemistry and The State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
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9
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Zhang J, Yang JD, Cheng JP. Recent progress in reactivity study and synthetic application of N-heterocyclic phosphorus hydrides. Natl Sci Rev 2021; 8:nwaa253. [PMID: 34691616 PMCID: PMC8288402 DOI: 10.1093/nsr/nwaa253] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 11/23/2022] Open
Abstract
N-heterocyclic phosphines (NHPs) have recently emerged as a new group of promising catalysts for metal-free reductions, owing to their unique hydridic reactivity. The excellent hydricity of NHPs, which rivals or even exceeds those of many metal-based hydrides, is the result of hyperconjugative interactions between the lone-pair electrons on N atoms and the adjacent σ*(P–H) orbital. Compared with the conventional protic reactivity of phosphines, this umpolung P–H reactivity leads to hydridic selectivity in NHP-mediated reductions. This reactivity has therefore found many applications in the catalytic reduction of polar unsaturated bonds and in the hydroboration of pyridines. This review summarizes recent progress in studies of the reactivity and synthetic applications of these phosphorus-based hydrides, with the aim of providing practical information to enable exploitation of their synthetically useful chemistry.
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Affiliation(s)
- Jingjing Zhang
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Jin-Dong Yang
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Jin-Pei Cheng
- Center of Basic Molecular Science, Department of Chemistry, Tsinghua University, Beijing 100084, China
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10
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Yang L, Zhang S, Zeng G. Mechanistic Insight into the 1,3,2-Diazaphospholene-Catalyzed Reductant (HBpin/NH 3BH 3)-Controlled Reaction of Allyl 2-Phenylacrylate: Claisen Rearrangement or Hydrogenation? J Phys Chem A 2021; 125:8658-8667. [PMID: 34582211 DOI: 10.1021/acs.jpca.1c06828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mechanistic study on the 1,3,2-diazaphospholene (1)-catalyzed reduction reaction of allyl 2-phenylacrylate 4 with HBpin or ammonia borane (AB) was systematically performed by the density functional theory (DFT) method. When HBpin is employed as the reductant, the reductive Ireland-Claisen (IC) rearrangement reaction occurs. First, the active species P-hydrido-1,3,2-diazaphospholene 3 is generated through the metathesis reaction of 1 with HBpin. Next, the terminal C═C double bond of 4 is inserted into the P-H bond of 3 to produce 6a through the 1,2-addition (Markovnikov) step, which is followed by the pinB-H bond activation to afford key boron enolate 8. Then, 8 undergoes the [3,3] rearrangement that is followed by the alcoholysis reaction with methanol leading to the final product γ,δ-unsaturated carboxylic acid. The [3,3] rearrangement step is the rate-determining step with the Gibbs energy barrier (ΔG≠) and Gibbs reaction energy (ΔG) of 23.9 and -27.5 kcal/mol, respectively. When AB is employed as the reductant, the transfer hydrogenation reaction occurs through two comparable pathways, 1,2- and 1,4-transfer hydrogenation pathways. The former pathway directly leads to the hydrogenation product with the ΔG≠ and ΔG values of 22.4 and -27.7 kcal/mol, respectively. The latter pathway produces an enolate intermediate (rate-determining step, ΔG≠/ΔG = 24.1/-0.3 kcal/mol) first, which then prefers to undergo the enol-keto tautomerism instead of the [3,3] rearrangement to afford the hydrogenation product. Obviously, the generation of the boron enolate plays a crucial role in the reductive IC rearrangement reaction because it prevents the enol-keto tautomerism.
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Affiliation(s)
- Linlin Yang
- Kuang Yaming Honors School, Institute for Brain Sciences, Nanjing University, Nanjing 210023, China
| | - Shuoqi Zhang
- Kuang Yaming Honors School, Institute for Brain Sciences, Nanjing University, Nanjing 210023, China
| | - Guixiang Zeng
- Kuang Yaming Honors School, Institute for Brain Sciences, Nanjing University, Nanjing 210023, China
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11
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12
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Zhu L, Zhang L, Yang Z, Pu M, Lei M. A theoretical study of the hydroboration of α,β-unsaturated carbonyl compounds catalyzed by a metal-free complex and subsequent C–C coupling with acetonitrile. NEW J CHEM 2021. [DOI: 10.1039/d1nj02218k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, the density functional theory (DFT) method was employed to investigate the reaction mechanism of the selective hydroboration of α,β-unsaturated carbonyl compounds catalyzed by the metal-free complex 1,3,2-diazaphospholene (DAP).
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Affiliation(s)
- Ling Zhu
- State Key Laboratory of Chemical Resource Engineering
- Institute of Computational Chemistry
- College of Chemistry
- Beijing University of Chemical Technology
- Beijing
| | - Lin Zhang
- State Key Laboratory of Chemical Resource Engineering
- Institute of Computational Chemistry
- College of Chemistry
- Beijing University of Chemical Technology
- Beijing
| | - Zuoyin Yang
- State Key Laboratory of Chemical Resource Engineering
- Institute of Computational Chemistry
- College of Chemistry
- Beijing University of Chemical Technology
- Beijing
| | - Min Pu
- State Key Laboratory of Chemical Resource Engineering
- Institute of Computational Chemistry
- College of Chemistry
- Beijing University of Chemical Technology
- Beijing
| | - Ming Lei
- State Key Laboratory of Chemical Resource Engineering
- Institute of Computational Chemistry
- College of Chemistry
- Beijing University of Chemical Technology
- Beijing
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13
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Abstract
Diazaphospholenes have recently emerged as main-group hydride transfer catalysts. This review will briefly summarize the common structural variants of diazaphospholenes, and the properties that make them superb hydride transfer catalysts, followed by a critical examination of the various preparative routes toward diazaphospholenes. Finally, an in-depth examination of the reactivity of diazaphospholenes in contemporary catalysis, including asymmetric catalysis will be undertaken.
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Affiliation(s)
- Alexander W H Speed
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, CanadaB3H 4R2.
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14
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Lipshultz JM, Fu Y, Liu P, Radosevich AT. Organophosphorus-catalyzed relay oxidation of H-Bpin: electrophilic C-H borylation of heteroarenes. Chem Sci 2020; 12:1031-1037. [PMID: 34163869 PMCID: PMC8179051 DOI: 10.1039/d0sc05620k] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A nontrigonal phosphorus triamide (1, P{N[o-NMe-C6H4]2}) is shown to catalyze C–H borylation of electron-rich heteroarenes with pinacolborane (HBpin) in the presence of a mild chloroalkane reagent. C–H borylation proceeds for a range of electron-rich heterocycles including pyrroles, indoles, and thiophenes of varied substitution. Mechanistic studies implicate an initial P–N cooperative activation of HBpin by 1 to give P-hydrido diazaphospholene 2, which is diverted by Atherton–Todd oxidation with chloroalkane to generate P-chloro diazaphospholene 3. DFT calculations suggest subsequent oxidation of pinacolborane by 3 generates chloropinacolborane (ClBpin) as a transient electrophilic borylating species, consistent with observed substituent effects and regiochemical outcomes. These results illustrate the targeted diversion of established reaction pathways in organophosphorus catalysis to enable a new mode of main group-catalyzed C–H borylation. A nontrigonal phosphorus triamide (1, P{N[o-NMe-C6H4]2}) is shown to catalyze C–H borylation of electron-rich heteroarenes with pinacolborane (HBpin) in the presence of a mild chloroalkane reagent.![]()
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Affiliation(s)
- Jeffrey M Lipshultz
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
| | - Yue Fu
- Department of Chemistry, University of Pittsburgh 219 Parkman Avenue Pittsburgh PA 15260 USA
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh 219 Parkman Avenue Pittsburgh PA 15260 USA
| | - Alexander T Radosevich
- Department of Chemistry, Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge MA 02139 USA
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15
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Ould DMC, Melen RL. Diazaphospholene and Diazaarsolene Derived Homogeneous Catalysis. Chemistry 2020; 26:9835-9845. [PMID: 32452586 PMCID: PMC7496616 DOI: 10.1002/chem.202001734] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/25/2020] [Indexed: 12/26/2022]
Abstract
The past 20 years has seen significant advances in main group chemistry and their use in catalysis. This Minireview showcases the recent emergence of phosphorus and arsenic containing heterocycles as catalysts. With that, we discuss how the Group 15 compounds diazaphospholenes, diazaarsolenes, and their cationic counterparts have proven to be highly effective catalysts for a wide range of reduction transformations. This Minireview highlights how the initial discovery by Gudat of the hydridic nature of the P−H bond in these systems led to these compounds being used as catalysts and discusses the wide range of examples currently present in the literature.
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Affiliation(s)
- Darren M C Ould
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Cardiff, CF10 3AT, Cymru/Wales, UK
| | - Rebecca L Melen
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Cardiff, CF10 3AT, Cymru/Wales, UK
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16
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Zhang J, Yang JD, Cheng JP. Diazaphosphinyl radical-catalyzed deoxygenation of α-carboxy ketones: a new protocol for chemo-selective C-O bond scission via mechanism regulation. Chem Sci 2020; 11:8476-8481. [PMID: 34123107 PMCID: PMC8163385 DOI: 10.1039/d0sc03220d] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/27/2020] [Indexed: 11/22/2022] Open
Abstract
C-O bond cleavage is often a key process in defunctionalization of organic compounds as well as in degradation of natural polymers. However, it seldom occurs regioselectively for different types of C-O bonds under metal-free mild conditions. Here we report a facile chemo-selective cleavage of the α-C-O bonds in α-carboxy ketones by commercially available pinacolborane under the catalysis of diazaphosphinane based on a mechanism switch strategy. This new reaction features high efficiency, low cost and good group-tolerance, and is also amenable to catalytic deprotection of desyl-protected carboxylic acids and amino acids. Mechanistic studies indicated an electron-transfer-initiated radical process, underlining two crucial steps: (1) the initiator azodiisobutyronitrile switches originally hydridic reduction to kinetically more accessible electron reduction; and (2) the catalytic phosphorus species upconverts weakly reducing pinacolborane into strongly reducing diazaphosphinane.
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Affiliation(s)
- Jingjing Zhang
- Department of Chemistry, Center of Basic Molecular Science, Tsinghua University Beijing 100084 China
| | - Jin-Dong Yang
- Department of Chemistry, Center of Basic Molecular Science, Tsinghua University Beijing 100084 China
| | - Jin-Pei Cheng
- Department of Chemistry, Center of Basic Molecular Science, Tsinghua University Beijing 100084 China
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University Tianjin 300071 China
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17
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Reed JH, Cramer N. 1,3,2‐Diazaphospholenes Catalyze the Conjugate Reduction of Substituted Acrylic Acids. ChemCatChem 2020. [DOI: 10.1002/cctc.202000662] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- John H. Reed
- Laboratory of Asymmetric Catalysis and Synthesis EPFL SB ISIC LCSA, BCH 4305 1015 Lausanne (Switzerland)
| | - Nicolai Cramer
- Laboratory of Asymmetric Catalysis and Synthesis EPFL SB ISIC LCSA, BCH 4305 1015 Lausanne (Switzerland)
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18
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Lundrigan T, Tien CH, Robertson KN, Speed AWH. Air and water stable secondary phosphine oxides as diazaphospholene precatalysts. Chem Commun (Camb) 2020; 56:8027-8030. [PMID: 32159538 DOI: 10.1039/d0cc01072c] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Secondary phosphine oxides, which are air and water stable, and purifiable by chromatography generate phosphenium or phosphorus hydride catalysts in situ.
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19
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Reed JH, Klett J, Steven C, Cramer N. Stay positive: catalysis with 1,3,2-diazaphospholenes. Org Chem Front 2020. [DOI: 10.1039/d0qo00848f] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fundamental properties and recent advances in the catalytic application of 1,3,2-diazaphospholenes are reviewed, and future directions for the field are presented.
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Affiliation(s)
- John H. Reed
- Laboratory of Asymmetric Synthesis and Catalysis
- Institute of Chemical Sciences and Chemical Engineering
- Ecole Polytechnique Fédérale de Lausanne (EPFL)
- 1015 Lausanne
- Switzerland
| | - Johannes Klett
- Laboratory of Asymmetric Synthesis and Catalysis
- Institute of Chemical Sciences and Chemical Engineering
- Ecole Polytechnique Fédérale de Lausanne (EPFL)
- 1015 Lausanne
- Switzerland
| | - Craig Steven
- Laboratory of Asymmetric Synthesis and Catalysis
- Institute of Chemical Sciences and Chemical Engineering
- Ecole Polytechnique Fédérale de Lausanne (EPFL)
- 1015 Lausanne
- Switzerland
| | - Nicolai Cramer
- Laboratory of Asymmetric Synthesis and Catalysis
- Institute of Chemical Sciences and Chemical Engineering
- Ecole Polytechnique Fédérale de Lausanne (EPFL)
- 1015 Lausanne
- Switzerland
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20
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Wang S, Liu Y, Cramer N. Asymmetric Alkenyl C−H Functionalization by Cp
x
Rh
III
forms 2
H
‐Pyrrol‐2‐ones through [4+1]‐Annulation of Acryl Amides and Allenes. Angew Chem Int Ed Engl 2019; 58:18136-18140. [DOI: 10.1002/anie.201909971] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/20/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Shou‐Guo Wang
- Laboratory of Asymmetric Catalysis and SynthesisEPFL SB ISIC LCSA, BCH 4305 CH-1015 Lausanne Switzerland
| | - Yang Liu
- Laboratory of Asymmetric Catalysis and SynthesisEPFL SB ISIC LCSA, BCH 4305 CH-1015 Lausanne Switzerland
- Dipartimento di ChimicaUniversità di Bologna via Selmi 2 40126 Bologna Italy
| | - Nicolai Cramer
- Laboratory of Asymmetric Catalysis and SynthesisEPFL SB ISIC LCSA, BCH 4305 CH-1015 Lausanne Switzerland
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21
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Wang S, Liu Y, Cramer N. Asymmetric Alkenyl C−H Functionalization by Cp
x
Rh
III
forms 2
H
‐Pyrrol‐2‐ones through [4+1]‐Annulation of Acryl Amides and Allenes. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201909971] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Shou‐Guo Wang
- Laboratory of Asymmetric Catalysis and SynthesisEPFL SB ISIC LCSA, BCH 4305 CH-1015 Lausanne Switzerland
| | - Yang Liu
- Laboratory of Asymmetric Catalysis and SynthesisEPFL SB ISIC LCSA, BCH 4305 CH-1015 Lausanne Switzerland
- Dipartimento di ChimicaUniversità di Bologna via Selmi 2 40126 Bologna Italy
| | - Nicolai Cramer
- Laboratory of Asymmetric Catalysis and SynthesisEPFL SB ISIC LCSA, BCH 4305 CH-1015 Lausanne Switzerland
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22
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Chacón‐Terán MA, Rodríguez‐Lugo RE, Wolf R, Landaeta VR. Transfer Hydrogenation of Azo Compounds with Ammonia Borane Using a Simple Acyclic Phosphite Precatalyst. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900572] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Miguel A. Chacón‐Terán
- Departamento de Química Universidad Simón Bolívar Valle de Sartenejas, Apartado 89000 Caracas 1020-A Venezuela
| | - Rafael E. Rodríguez‐Lugo
- Laboratorio de Química Bioinorgánica Centro de Química Instituto Venezolano de Investigaciones Científicas (IVIC) Carretera Panamericana Km. 11. Caracas 1020‐A Venezuela
| | - Robert Wolf
- Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany
| | - Vanessa R. Landaeta
- Departamento de Química Universidad Simón Bolívar Valle de Sartenejas, Apartado 89000 Caracas 1020-A Venezuela
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