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Shennan BDA, Berheci D, Crompton JL, Davidson TA, Field JL, Williams BA, Dixon DJ. Branching out: redox strategies towards the synthesis of acyclic α-tertiary ethers. Chem Soc Rev 2022; 51:5878-5929. [PMID: 35770619 DOI: 10.1039/d1cs00669j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Acyclic α-tertiary ethers represent a highly prevalent functionality, common to high-value bioactive molecules, such as pharmaceuticals and natural products, and feature as crucial synthetic handles in their construction. As such their synthesis has become an ever-more important goal in synthetic chemistry as the drawbacks of traditional strong base- and acid-mediated etherifications have become more limiting. In recent years, the generation of highly reactive intermediates via redox approaches has facilitated the synthesis of highly sterically-encumbered ethers and accordingly these strategies have been widely applied in α-tertiary ether synthesis. This review summarises and appraises the state-of-the-art in the application of redox strategies enabling acyclic α-tertiary ether synthesis.
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Affiliation(s)
- Benjamin D A Shennan
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Diana Berheci
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Jessica L Crompton
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Timothy A Davidson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Joshua L Field
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Benedict A Williams
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
| | - Darren J Dixon
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
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Gangadhar M, Ramesh V, Prasad VS, Adiyala PR. Silver Ions Promoted Palladium-Catalyzed Inactive β-C(sp 3)-H Bond Arylation in Batch and Continuous-Flow Conditions. J Org Chem 2022; 87:9607-9618. [PMID: 35833382 DOI: 10.1021/acs.joc.2c00606] [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
A palladium(II)-catalyzed protocol for inactive β-C(sp3)-H bond functionalization has been first accomplished. The reaction proceeds through five-membered carbocycles for the formation of C-C bonds via the Pd(II)/Pd(IV) cycle. This reaction was carried out with various aryl iodides and benzothiazoles/benzoxazoles/benzimidazoles, which were well-tolerated in this reaction and successfully generated β-C(sp3)-H arylated products. Further implementation of this batch protocol to continuous flow by utilizing a PTFE (polytetrafluoroethylene) capillary reactor enhanced the reaction efficiency and decreased the reaction time (18.4 min) as compared to batch conditions (8 h). Even on the gram scale, the process produced excellent yield with negligible diarylations. Functional group tolerance, a continuous-flow approach, and easy-to-handle reaction conditions make this inactive β-C(sp3)-H bond functionalization protocol very attractive.
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Affiliation(s)
- Maram Gangadhar
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Vankudoth Ramesh
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Vadla Shiva Prasad
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Praveen Reddy Adiyala
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, Telangana, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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Renzi P, Azzi E, Bessone E, Ghigo G, Parisotto S, Pellegrino F, Deagostino A. Blue light enhanced Heck arylation at room temperature applied to allenes. Org Chem Front 2022. [DOI: 10.1039/d1qo01631h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A blue light enhanced synthesis of 2-vinyl pirrolidines and piperidines through a domino Heck arylation–cyclisation applied to allenyl amines is described. Essential is the role of the light in the aryl migration in the carbo-palladation step.
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Affiliation(s)
- Polyssena Renzi
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, 10125 Torino, Italy
| | - Emanuele Azzi
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, 10125 Torino, Italy
| | - Enrico Bessone
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, 10125 Torino, Italy
| | - Giovanni Ghigo
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, 10125 Torino, Italy
| | - Stefano Parisotto
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, 10125 Torino, Italy
| | - Francesco Pellegrino
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, 10125 Torino, Italy
| | - Annamaria Deagostino
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, 10125 Torino, Italy
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Huang H, Jing X, Zhong B, Meng C, Duan C. Cuprous Cluster-Based Coordination Sheets as Photocatalytic Regulators to Activate Oxygen, Benzoquinone, and Thianthrenium Salts. ACS APPLIED MATERIALS & INTERFACES 2021; 13:58498-58507. [PMID: 34854670 DOI: 10.1021/acsami.1c16280] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Cuprous clusters are well known for their important fluorescent properties and tunable redox behavior, but the coordinated protecting groups restrict their application in photocatalysis, in particular, the inner-sphere activation of substrates. By modifying fluorescent cuprous clusters with terminal iodides into two-dimensional coordination sheets, we report a photocatalytic regulator to synergistically combine electron transfer and energy transfer for the oxidative coupling of benzoquinone and terminal alkynes. Under visible light irradiation, the well-modified excited state of the cuprous clusters in the coordination sheets reduces benzoquinones to generate aoxy radicals through electron transfer and activates oxygen through energy transfer. The aoxy radicals interact with copper-coordinated phenylacetylene to form an active intermediate, which is further oxidized by the in situ formed active oxygen species and aryl ketones are obtained. The warranted potential of the excited coordination sheets enables the reductive activation of thianthrenium salts as radical precursors, facilitating radical capture and further C-N coupling via an inner-sphere activation mechanism. The new catalytic approach optimizes the redox properties and excited-state lifetime, shortens the electron transfer steps, and promotes the potential collision of a low concentration of active species in tandem catalytic cycles, thus paving a new way to develop ecologically benign, cost-effective, multipurpose, and flexible catalytic systems.
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Affiliation(s)
- Huilin Huang
- State Key Laboratory of Fine Chemicals, Zhang Dayu College of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China
| | - Xu Jing
- State Key Laboratory of Fine Chemicals, Zhang Dayu College of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China
| | - Bingwen Zhong
- State Key Laboratory of Fine Chemicals, Zhang Dayu College of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China
| | - Changgong Meng
- State Key Laboratory of Fine Chemicals, Zhang Dayu College of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China
| | - Chunying Duan
- State Key Laboratory of Fine Chemicals, Zhang Dayu College of Chemistry, Dalian University of Technology, Dalian 116024, P. R. China
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Shan QC, Hu LM, Qin W, Hu XH. Copper-Catalyzed Cross-Nucleophile Coupling of β-Allenyl Silanes with Tertiary C-H Bonds: A Radical Approach to Branched 1,3-Dienes. Org Lett 2021; 23:6041-6045. [PMID: 34279969 DOI: 10.1021/acs.orglett.1c02112] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Described herein is a distinctive approach to branched 1,3-dienes through oxidative coupling of two nucleophilic substrates, β-allenyl silanes, and hydrocarbons appending latent functionality by copper catalysis. Notably, C(sp3)-H dienylation proceeded in a regiospecific manner, even in the presence of competitive C-H bonds that are capable of occurring hydrogen atom transfer process, such as those located at benzylic and other tertiary sites, or adjacent to an oxygen atom. Control experiments support the intermediacy of functionalized alkyl radicals.
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Affiliation(s)
- Qi-Chao Shan
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Lu-Min Hu
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Wei Qin
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Xu-Hong Hu
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China
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Abstract
This review summarizes the visible light mediated strategies for the functionalization of allenes.
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Affiliation(s)
- Jitender Singh
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee-247667, India
| | - Anoop Sharma
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee-247667, India
| | - Anuj Sharma
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee-247667, India
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Gu X, Wei Y, Shi M. Construction of polysubstituted spiro[2.3] or [3.3] cyclic frameworks fused with a tosylated pyrrolidine promoted by visible-light-induced photosensitization. Org Chem Front 2021. [DOI: 10.1039/d1qo01373d] [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
A novel visible-light-induced intramolecular [2 + 2] cycloaddition of methylenecyclopropanes (MCPs) for the rapid construction of polysubstituted spiro[2.3] or [3.3] cyclic frameworks fused with a tosylated pyrrolidine.
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Affiliation(s)
- Xintao Gu
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, People's Republic of China
| | - Yin Wei
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, University of Chinese Academy of Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Min Shi
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, People's Republic of China
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, University of Chinese Academy of Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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