1
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Kumar R, Maurya V, Avinash A, Appayee C. Nonsilyl Bicyclic Secondary Amine Catalysts for the Asymmetric Transfer Hydrogenation of α,β-Unsaturated Aldehydes. J Org Chem 2024; 89:8586-8600. [PMID: 38836633 DOI: 10.1021/acs.joc.4c00523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
The first chiral synthesis of nonsilyl bicyclic secondary amine organocatalysts and their application to the asymmetric transfer hydrogenation of α,β-unsaturated aldehydes are disclosed. A lower catalytic loading (5 mol %) is demonstrated for the reduction of a wide range of α,β-unsaturated aldehydes (up to 97% yield and up to 99% ee). The application of this scalable methodology is showcased for the asymmetric synthesis of bioactive molecules such as phenoxanol, citronellol, ramelteon, and terikalant.
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Affiliation(s)
- Rohtash Kumar
- Department of Chemistry, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat 382055, India
| | - Vidyasagar Maurya
- Department of Chemistry, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat 382055, India
| | - Avinash Avinash
- Department of Chemistry, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat 382055, India
| | - Chandrakumar Appayee
- Department of Chemistry, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat 382055, India
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2
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Kadiyam RK, Sangolkar AA, Faizan M, Pawar R. Bispericyclic Ambimodal Dimerization of Pentafulvene: The Origin of Asynchronicity and Kinetic Selectivity of the Endo Transition State. J Org Chem 2024; 89:6813-6825. [PMID: 38661667 DOI: 10.1021/acs.joc.4c00186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The propensity of fulvenes to undergo dimerization has long been known, although the in-depth mechanism and electronic behavior during dimerization are still elusive. Herein, we made an attempt to gain insights into the reactivity of pentafulvene for Diels-Alder (DA) and [6 + 4]-cycloadditions via conventional and ambimodal routes. The result emphasizes that pentafulvene dimerization preferentially proceeds through a unique bifurcation mechanism where two DA pathways merge together to produce two degenerate [4 + 2]-cycloadducts from a single TS. Despite the [6 + 4]-cycloadduct being thermodynamically preferred, [4 + 2]-cycloaddition reactions are kinetically driven. Singlet biradicaloid is involved in through-space 6e- delocalization as a secondary orbital interaction that originates asynchronicity and stabilizes the bispericyclic transition state (TS). The transformation of various actively participating intrinsic bonding orbitals (IBOs) unambiguously forecasts the formation of multiple products from a single TS and rationalizes the mechanism of ambimodal reactions that are rather difficult to probe with other analyses. The changes in active IBOs clearly distinguish the conventional reactions from bifurcation reactions and can be employed to characterize and confirm the ambimodal mechanism. This report gains a crucial theoretical insight into the mechanism of bifurcation, the origin of asynchronicity, and electronic behavior in ambimodal TS, which will certainly be of enormous value for future studies.
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Affiliation(s)
- Rama Krishna Kadiyam
- Laboratory of Advanced Computation and Theory for Materials and Chemistry, Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana 506004, India
| | - Akanksha Ashok Sangolkar
- Laboratory of Advanced Computation and Theory for Materials and Chemistry, Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana 506004, India
| | - Mohmmad Faizan
- Laboratory of Advanced Computation and Theory for Materials and Chemistry, Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana 506004, India
| | - Ravinder Pawar
- Laboratory of Advanced Computation and Theory for Materials and Chemistry, Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana 506004, India
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3
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Xiong TZ, Yisimayili N, Lu CD. Stereoselective Electrophilic Chlorination of β,β-Disubstituted Enesulfinamides with Chloramine-T: Asymmetric Synthesis of Acyclic α,α-Disubstituted α-Chlorinated Carbonyl Surrogates. Org Lett 2024; 26:1851-1856. [PMID: 38386702 DOI: 10.1021/acs.orglett.4c00059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Enamine and iminium ion-mediated asymmetric organocatalysis was not successful in achieving highly stereoselective α-chlorination of acyclic α,α-disubstituted carbonyls. To address this limitation, an alternative method was developed, which involved the use of geometry-defined persubstituted enesulfinamides to intercept the electrophilic chlorinating reagent. This approach enables the asymmetric construction of challenging acyclic α,α-disubstituted α-chlorinated ketimines with a high degree of stereoselectivity. The use of chloramine-T, a cost-effective and stable chlorine source rarely utilized in asymmetric electrophilic chlorination, plays a crucial role in achieving superior stereocontrol.
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Affiliation(s)
- Teng-Zhao Xiong
- School of Chemical Science and Technology, Yunnan University, Kunming, Yunnan 650091, China
| | | | - Chong-Dao Lu
- School of Chemical Science and Technology, Yunnan University, Kunming, Yunnan 650091, China
- School of Health, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
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4
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Han X, Chen F, Li H, Ge R, Shen Q, Duan P, Sheng X, Zhang W. Reaction engineering blocks ether cleavage for synthesizing chiral cyclic hemiacetals catalyzed by unspecific peroxygenase. Nat Commun 2024; 15:1235. [PMID: 38336996 PMCID: PMC10858125 DOI: 10.1038/s41467-024-45545-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 01/24/2024] [Indexed: 02/12/2024] Open
Abstract
Hemiacetal compounds are valuable building blocks in synthetic chemistry, but their enzymatic synthesis is limited and often hindered by the instability of hemiacetals in aqueous environments. Here, we show that this challenge can be addressed through reaction engineering by using immobilized peroxygenase from Agrocybe aegerita (AaeUPO) under neat reaction conditions, which allows for the selective C-H bond oxyfunctionalization of environmentally significant cyclic ethers to cyclic hemiacetals. A wide range of chiral cyclic hemiacetal products are prepared in >99% enantiomeric excess and 95170 turnover numbers of AaeUPO. Furthermore, by changing the reaction medium from pure organic solvent to alkaline aqueous conditions, cyclic hemiacetals are in situ transformed into lactones. Lactams are obtained under the applied conditions, albeit with low enzyme activity. These findings showcase the synthetic potential of AaeUPO and offer a practical enzymatic approach to produce chiral cyclic hemiacetals through C-H oxyfunctionalization under mild conditions.
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Affiliation(s)
- Xiaofeng Han
- College of Chemistry and Materials Science, Inner Mongolia Minzu University, Tongliao, 028000, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin, 300308, China
| | - Fuqiang Chen
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin, 300308, China
| | - Huanhuan Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin, 300308, China
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Ran Ge
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin, 300308, China
| | - Qianqian Shen
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin, 300308, China
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Peigao Duan
- School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Xiang Sheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin, 300308, China.
- National Center of Technology Innovation for Synthetic Biology, 32 West 7th Avenue, Tianjin, 300308, China.
| | - Wuyuan Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin, 300308, China.
- National Center of Technology Innovation for Synthetic Biology, 32 West 7th Avenue, Tianjin, 300308, China.
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5
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Li Z, Wang B, Zhang C, Lo WY, Yang L, Sun J. Catalytic Enantioselective Nucleophilic α-Chlorination of Ketones with NaCl. J Am Chem Soc 2024; 146:2779-2788. [PMID: 38238317 DOI: 10.1021/jacs.3c12826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Catalytic enantioselective α-chlorination of ketones is a highly desirable process. Different from the conventional approaches that employ corrosive electrophilic chlorination reagents, the process disclosed here employs nucleophilic chloride, aqueous NaCl solution, and even seawater, as green inexpensive chlorine sources. This mechanistically distinct and electronically opposite approach provides facile access to diverse highly enantioenriched acyclic α-chloro ketones that are less straightforward by conventional approaches. With a chiral thiourea catalyst, a range of racemic α-keto sulfonium salts underwent enantioconvergent carbon-chlorine bond formation with high efficiency and excellent enantioselectivity under mild conditions. The sulfonium motif plays a crucial triple role by permitting smooth dynamic kinetic resolution to take place via a chiral anion binding mechanism in a well-designed phase-transfer system. This protocol represents a new general platform for the asymmetric nucleophilic α-functionalization of carbonyl compounds.
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Affiliation(s)
- Zhiyang Li
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
- Shenzhen Research Institute, HKUST, No. 9 Yuexing First Rd, Shenzhen 518057, China
| | - Baocheng Wang
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
| | - Chaoshen Zhang
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
| | - Wai Yam Lo
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
| | - Liangliang Yang
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
| | - Jianwei Sun
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China
- Shenzhen Research Institute, HKUST, No. 9 Yuexing First Rd, Shenzhen 518057, China
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6
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Lennon G, Dingwall P. Enabling High Throughput Kinetic Experimentation by Using Flow as a Differential Kinetic Technique. Angew Chem Int Ed Engl 2024; 63:e202318146. [PMID: 38078481 PMCID: PMC10952970 DOI: 10.1002/anie.202318146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Indexed: 12/23/2023]
Abstract
Kinetic data is most commonly collected through the generation of time-series data under either batch or flow conditions. Existing methods to generate kinetic data in flow collect integral data (concentration over time) only. Here, we report a method for the rapid and direct collection of differential kinetic data (direct measurement of rate) in flow by performing a series of instantaneous rate measurements on sequential small-scale reactions. This technique decouples the time required to generate a full kinetic profile from the time required for a reaction to reach completion, enabling high throughput kinetic experimentation. In addition, comparison of kinetic profiles constructed at different residence times allows the robustness, or stability, of homogeneously catalysed reactions to be interrogated. This approach makes use of a segmented flow platform which was shown to quantitatively reproduce batch kinetic data. The proline mediated aldol reaction was chosen as a model reaction to perform a high throughput kinetic screen of 216 kinetic profiles in 90 hours, one every 25 minutes, which would have taken an estimated continuous 3500 hours in batch, an almost 40-fold increase in experimental throughput matched by a corresponding reduction in material consumption.
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Affiliation(s)
- Gavin Lennon
- School of Chemistry and Chemical EngineeringQueen's University BelfastDavid Keir Building, Stranmillis RoadBelfastBT9 5AGUK
| | - Paul Dingwall
- School of Chemistry and Chemical EngineeringQueen's University BelfastDavid Keir Building, Stranmillis RoadBelfastBT9 5AGUK
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7
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Li Z, Ma C, Zhao L, Lin Z, Hu Y, Zhao J, Yu X. High atomic utilization conversion of ethers into furancarbaldehydes via an ether oxidation iminium-ion activation cascade strategy. Org Biomol Chem 2023; 21:8094-8097. [PMID: 37789756 DOI: 10.1039/d3ob01120h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
A novel organocatalytic one-pot cascade ether oxidation iminium-ion activation strategy for the synthesis of naphtho[2,1-b]furan-1-carbaldehyde and benzofuran-3-carbaldehyde from high atomic utilization transformation of aryl allyl ethers has been developed. Its synthetic application will provide a new ether oxidation iminium-ion activation cascade tool for the efficient synthesis of complex molecules.
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Affiliation(s)
- Zheyao Li
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, and State Key Laboratory of Bioengineering Reactors, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
| | - Chunmei Ma
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, and State Key Laboratory of Bioengineering Reactors, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
| | - Lin Zhao
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, and State Key Laboratory of Bioengineering Reactors, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
| | - Zhongren Lin
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, and State Key Laboratory of Bioengineering Reactors, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
| | - Yang Hu
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, and State Key Laboratory of Bioengineering Reactors, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
| | - Jianhong Zhao
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, and State Key Laboratory of Bioengineering Reactors, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
| | - Xinhong Yu
- Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, and State Key Laboratory of Bioengineering Reactors, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
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8
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Kuang Y, Lai J, Reid JP. Transferrable selectivity profiles enable prediction in synergistic catalyst space. Chem Sci 2023; 14:1885-1895. [PMID: 36819850 PMCID: PMC9931051 DOI: 10.1039/d2sc05974f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/10/2023] [Indexed: 01/19/2023] Open
Abstract
Organometallic intermediates participate in many multi-catalytic enantioselective transformations directed by a chiral catalyst, but the requirement of optimizing two catalyst components is a significant barrier to widely adopting this approach for chiral molecule synthesis. Algorithms can potentially accelerate the screening process by developing quantitative structure-function relationships from large experimental datasets. However, the chemical data available in this catalyst space is limited. Herein, we report a data-driven strategy that effectively translates selectivity relationships trained on enantioselectivity outcomes derived from one catalyst reaction systems where an abundance of data exists, to synergistic catalyst space. We describe three case studies involving different modes of catalysis (Brønsted acid, chiral anion, and secondary amine) that substantiate the prospect of this approach to predict and elucidate selectivity in reactions where more than one catalyst is involved. Ultimately, the success in applying our approach to diverse areas of asymmetric catalysis implies that this general workflow should find broad use in the study and development of new enantioselective, multi-catalytic processes.
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Affiliation(s)
- Yutao Kuang
- Department of Chemistry, University of British Columbia 2036 Main Mall, Vancouver British Columbia V6T 1Z1 Canada
| | - Junshan Lai
- Department of Chemistry, University of British Columbia 2036 Main Mall, Vancouver British Columbia V6T 1Z1 Canada
| | - Jolene P. Reid
- Department of Chemistry, University of British Columbia2036 Main Mall, VancouverBritish ColumbiaV6T 1Z1Canada
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9
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Organic reaction mechanism classification using machine learning. Nature 2023; 613:689-695. [PMID: 36697863 DOI: 10.1038/s41586-022-05639-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 12/08/2022] [Indexed: 01/26/2023]
Abstract
A mechanistic understanding of catalytic organic reactions is crucial for the design of new catalysts, modes of reactivity and the development of greener and more sustainable chemical processes1-13. Kinetic analysis lies at the core of mechanistic elucidation by facilitating direct testing of mechanistic hypotheses from experimental data. Traditionally, kinetic analysis has relied on the use of initial rates14, logarithmic plots and, more recently, visual kinetic methods15-18, in combination with mathematical rate law derivations. However, the derivation of rate laws and their interpretation require numerous mathematical approximations and, as a result, they are prone to human error and are limited to reaction networks with only a few steps operating under steady state. Here we show that a deep neural network model can be trained to analyse ordinary kinetic data and automatically elucidate the corresponding mechanism class, without any additional user input. The model identifies a wide variety of classes of mechanism with outstanding accuracy, including mechanisms out of steady state such as those involving catalyst activation and deactivation steps, and performs excellently even when the kinetic data contain substantial error or only a few time points. Our results demonstrate that artificial-intelligence-guided mechanism classification is a powerful new tool that can streamline and automate mechanistic elucidation. We are making this model freely available to the community and we anticipate that this work will lead to further advances in the development of fully automated organic reaction discovery and development.
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10
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Marchand A, Mishra R, Bernard A, Dumez J. Online Reaction Monitoring with Fast and Flow‐Compatible Diffusion NMR Spectroscopy. Chemistry 2022; 28:e202201175. [DOI: 10.1002/chem.202201175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Indexed: 11/08/2022]
Affiliation(s)
| | - Rituraj Mishra
- Nantes Université CNRS CEISAM UMR 6230 44000 Nantes France
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11
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Lustosa DM, Milo A. Mechanistic Inference from Statistical Models at Different Data-Size Regimes. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Danilo M. Lustosa
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Anat Milo
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
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12
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Hutchinson G, Alamillo-Ferrer C, Fernández-Pascual M, Burés J. Organocatalytic Enantioselective α-Bromination of Aldehydes with N-Bromosuccinimide. J Org Chem 2022; 87:7968-7974. [PMID: 35617931 PMCID: PMC9207931 DOI: 10.1021/acs.joc.2c00600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
![]()
Despite the wealth
of existing organocatalytic, enantioselective
transformations, the α-bromination of aldehydes remains a challenging
reaction. The four examples reported to date require expensive, inconvenient
brominating agents to achieve the desired products in excellent yields
and enantioselectivities. The preferred brominating agent, N-bromosuccinimide (NBS), has been repeatedly discarded
for these reactions because it results in low yields and relatively
poor enantioselectivities. We describe a methodology that uses NBS
and performs excellently with low catalyst loadings, short reaction
times, and mild temperatures.
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Affiliation(s)
- George Hutchinson
- The University of Manchester, Department of Chemistry, Oxford Road, M13 9PL Manchester, U.K
| | - Carla Alamillo-Ferrer
- The University of Manchester, Department of Chemistry, Oxford Road, M13 9PL Manchester, U.K
| | | | - Jordi Burés
- The University of Manchester, Department of Chemistry, Oxford Road, M13 9PL Manchester, U.K
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13
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Nishimura K, Wang Y, Ogura Y, Kumagai J, Ishihara K. A π–Cu(II)−π Complex as an Extremely Active Catalyst for Enantioselective α-Halogenation of N-Acyl-3,5-dimethylpyrazoles. ACS Catal 2022. [DOI: 10.1021/acscatal.1c05500] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Kazuki Nishimura
- Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya 464-8603, Japan
| | - Yanzhao Wang
- Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya 464-8603, Japan
| | - Yoshihiro Ogura
- Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya 464-8603, Japan
| | - Jun Kumagai
- Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya 464-8603, Japan
| | - Kazuaki Ishihara
- Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya 464-8603, Japan
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14
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Zeidan N, Bicic S, Mayer RJ, Lebœuf D, Moran J. Hydroarylation of Enamides Enabled by HFIP via a Hexafluoroisopropyl Ether as Iminium Reservoir. Chem Sci 2022; 13:8436-8443. [PMID: 35919727 PMCID: PMC9297520 DOI: 10.1039/d2sc02012b] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/25/2022] [Indexed: 11/21/2022] Open
Abstract
Here we describe that HFIP greatly expands the scope with respect to both reaction partners of the Brønsted acid-catalyzed hydroarylation of enamides. The reaction is fast and practical and can...
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Affiliation(s)
- Nicolas Zeidan
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg 8 allée Gaspard Monge 67000 Strasbourg France
| | - Sergiu Bicic
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg 8 allée Gaspard Monge 67000 Strasbourg France
| | - Robert J Mayer
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg 8 allée Gaspard Monge 67000 Strasbourg France
| | - David Lebœuf
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg 8 allée Gaspard Monge 67000 Strasbourg France
| | - Joseph Moran
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg 8 allée Gaspard Monge 67000 Strasbourg France
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15
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Mohr LM, McCulley CH, Blom J, Lamhauge JN, Anker Jørgensen K. Investigation of the Organocatalytic Chlorination of 2-Phenylpropanal. Chemistry 2021; 27:17465-17475. [PMID: 34622997 DOI: 10.1002/chem.202103376] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Indexed: 11/08/2022]
Abstract
Results of an examination of the organocatalytic enantioselective α-chlorination of 2-phenylpropanal are described. Synthetic investigation including the screening of primary and secondary aminocatalysts, many different reaction conditions, and other α-branched aldehydes show that especially primary aminocatalysts can catalyze the formation of the α-chloro branched aldehydes in good yields, but only with moderate enantioselectivities. In order to try to understand the challenge in obtaining high enantioselectivity for the aminocatalytic α-chlorination of α-branched aldehydes a series of experimental investigations were performed employing 2-phenylpropanal as a model system. These investigations have been coupled with computational investigations, which provided important insight into the moderate enantioselectivity of this chlorination reaction. Analysis of the reaction showed, that the lack of control over the selectivity of formation of the (E)- and (Z)-enamine intermediate, and the clustering of reaction barriers of possible reaction pathways help to rationalize difficulties in producing high enantioselectivity.
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Affiliation(s)
- Lisa-Marie Mohr
- Department of Chemistry, Aarhus University, 8000, Aarhus, Denmark
| | | | - Jakob Blom
- Department of Chemistry, Aarhus University, 8000, Aarhus, Denmark
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16
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Abstract
Organocatalysts are abundantly used for various transformations, particularly to obtain highly enantio- and diastereomeric pure products by controlling the stereochemistry. These applications of organocatalysts have been the topic of several reviews. Organocatalysts have emerged as one of the very essential areas of research due to their mild reaction conditions, cost-effective nature, non-toxicity, and environmentally benign approach that obviates the need for transition metal catalysts and other toxic reagents. Various types of organocatalysts including amine catalysts, Brønsted acids, and Lewis bases such as N-heterocyclic carbene (NHC) catalysts, cinchona alkaloids, 4-dimethylaminopyridine (DMAP), and hydrogen bond-donating catalysts, have gained renewed interest because of their regioselectivity. In this review, we present recent advances in regiodivergent reactions that are governed by organocatalysts. Additionally, we briefly discuss the reaction pathways of achieving regiodivergent products by changes in conditions such as solvents, additives, or the temperature.
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17
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Margarita C, Villo P, Tuñon H, Dalla-Santa O, Camaj D, Carlsson R, Lill M, Ramström A, Lundberg H. Zirconium-catalysed direct substitution of alcohols: enhancing the selectivity by kinetic analysis. Catal Sci Technol 2021. [DOI: 10.1039/d1cy01219c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Kinetic analysis was used as a tool for rational optimization of catalytic direct substitution of alcohols to enable selective formation of ethers, thioethers, and Friedel–Crafts alkylation products using a moisture-tolerant and commercially available Zr complex.
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Affiliation(s)
- Cristiana Margarita
- Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 30, S-10044 Stockholm, Sweden
| | - Piret Villo
- Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 30, S-10044 Stockholm, Sweden
| | - Hernando Tuñon
- Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 30, S-10044 Stockholm, Sweden
| | - Oscar Dalla-Santa
- Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 30, S-10044 Stockholm, Sweden
| | - David Camaj
- Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 30, S-10044 Stockholm, Sweden
| | - Robin Carlsson
- Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 30, S-10044 Stockholm, Sweden
| | - Malin Lill
- Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 30, S-10044 Stockholm, Sweden
| | - Anja Ramström
- Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 30, S-10044 Stockholm, Sweden
| | - Helena Lundberg
- Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 30, S-10044 Stockholm, Sweden
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