1
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Liu M, Uyeda C. Redox Approaches to Carbene Generation in Catalytic Cyclopropanation Reactions. Angew Chem Int Ed Engl 2024; 63:e202406218. [PMID: 38752878 DOI: 10.1002/anie.202406218] [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: 04/01/2024] [Indexed: 06/15/2024]
Abstract
Transition metal-catalyzed carbene transfer reactions have a century-old history in organic chemistry and are a primary method for the synthesis of cyclopropanes. Much of the work in this field has focused on the use of diazo compounds and related precursors, which can transfer a carbene fragment to a catalyst with concomitant loss of a stable byproduct. Despite the utility of this approach, there are persistent limitations in the scope of viable carbenes, most notably those lacking stabilizing substituents. By coupling carbene transfer chemistry with two-electron redox cycles, it is possible to expand the available starting materials that can be used as carbene precursors. In this Minireview, we discuss emerging catalytic reductive cyclopropanation reactions using either gem-dihaloalkanes or carbonyl compounds. This strategy is inspired by classic stoichiometric transformations, such as the Simmons-Smith cyclopropanation and the Clemmensen reduction, but instead entails the formation of a catalytically generated transition metal carbene or carbenoid. We also present recent efforts to generate carbenes directly from methylene (CR2H2) groups via a formal 1,1-dehydrogenation. These reactions are currently restricted to substrates containing electron-withdrawing substituents, which serve to facilitate deprotonation and subsequent oxidation of the anion.
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Affiliation(s)
- Mingxin Liu
- Department of Chemistry, Purdue University, 560 Oval Dr., West Lafayette, IN 47907, USA
| | - Christopher Uyeda
- Department of Chemistry, Purdue University, 560 Oval Dr., West Lafayette, IN 47907, USA
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2
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Gber TE, Louis H, Ngana OC, Amodu IO, Ekereke EE, Benjamin I, Adalikwu SA, Adeyinka A. Yttrium- and zirconium-decorated Mg 12O 12-X (X = Y, Zr) nanoclusters as sensors for diazomethane (CH 2N 2) gas. RSC Adv 2023; 13:25391-25407. [PMID: 37636506 PMCID: PMC10448449 DOI: 10.1039/d3ra02939e] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 07/21/2023] [Indexed: 08/29/2023] Open
Abstract
Diazomethane (CH2N2) presents a notable hazard as a respiratory irritant, resulting in various adverse effects upon exposure. Consequently, there has been increasing concern in the field of environmental research to develop a sensor material that exhibits heightened sensitivity and conductivity for the detection and adsorption of this gas. Therefore, this study aims to provide a comprehensive analysis of the geometric structure of three systems: CH2N2@MgO (C1), CH2N2@YMgO (CY1), and CH2N2@ZrMgO (CZ1), in addition to pristine MgO nanocages. The investigation involves a theoretical analysis employing the DFT/ωB97XD method at the GenECP/6-311++G(d,p)/SDD level of theory. Notably, the examination of bond lengths within the MgO cage yielded specific values, including Mg15-O4 (1.896 Å), Mg19-O4 (1.952 Å), and Mg23-O4 (1.952 Å), thereby offering valuable insights into the structural properties and interactions with CH2N2 gas. Intriguingly, after the interaction, bond length variations were observed, with CH2N2@MgO exhibiting shorter bonds and CH2N2@YMgO showcasing longer bonds. Meanwhile, CH2N2@ZrMgO displayed shorter bonds, except for a longer bond in Mg19-O4, suggesting increased stability due to shorter bond distances. The study further investigated the electronic properties, revealing changes in the energy gap that influenced electrical conductivity and sensitivity. The energy gap increased for Zr@MgO, CH2N2@MgO, CH2N2@YMgO, and CH2N2@ZrMgO, indicating weak interactions on the MgO surface. Conversely, Y@MgO showed a decrease in energy, suggesting a strong interaction. The pure MgO surface exhibited the ability to donate and accept electrons, resulting in an energy gap of 4.799 eV. Surfaces decorated with yttrium and zirconium exhibited decreased energies of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), as well as decreased energy gap, indicating increased conductivity and sensitivity. Notably, Zr@MgO had the highest energy gap before CH2N2 adsorption, but C1 exhibited a significantly higher energy gap after adsorption, implying increased conductivity and sensitivity. The study also examined the density of states, demonstrating significant variations in the electronic properties of MgO and its decorated surfaces due to CH2N2 adsorption. Moreover, various analysis techniques were employed, including natural bond orbital (NBO), quantum theory of atoms in molecules (QTAIM), and noncovalent interaction (NCI) analysis, which provided insights into bonding, charge density, and intermolecular interactions. The findings contribute to a deeper understanding of the sensing mechanisms of CH2N2 gas on nanocage surfaces, shedding light on adsorption energy, conductivity, and recovery time. These results hold significance for gas-sensing applications and provide a basis for further exploration and development in this field.
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Affiliation(s)
- Terkumbur E Gber
- Computational and Bio-Simulation Research Group, University of Calabar Calabar Nigeria
- Department of Pure and Applied Chemistry, Faculty of Physical Sciences, University of Calabar Calabar Nigeria
| | - Hitler Louis
- Computational and Bio-Simulation Research Group, University of Calabar Calabar Nigeria
- Department of Pure and Applied Chemistry, Faculty of Physical Sciences, University of Calabar Calabar Nigeria
- Centre for Herbal Pharmacology and Environmental Sustainability, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education Kelambakkam-603103 Tamil Nadu India
| | - Obinna C Ngana
- Department of Chemical Sciences, Federal University of Wukari Wukari Taraba State Nigeria
| | - Ismail O Amodu
- Computational and Bio-Simulation Research Group, University of Calabar Calabar Nigeria
- Department of Mathematics, Faculty of Physical Sciences, University of Calabar Calabar Nigeria
| | - Ernest E Ekereke
- Computational and Bio-Simulation Research Group, University of Calabar Calabar Nigeria
- Department of Mathematics, Faculty of Physical Sciences, University of Calabar Calabar Nigeria
| | - Innocent Benjamin
- Computational and Bio-Simulation Research Group, University of Calabar Calabar Nigeria
| | - Stephen A Adalikwu
- Computational and Bio-Simulation Research Group, University of Calabar Calabar Nigeria
| | - Adedapo Adeyinka
- Department of Chemical Sciences, University of Johannesburg South Africa
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3
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Casas-Orozco D, Laky D, Wang V, Abdi M, Feng X, Wood E, Reklaitis GV, Nagy ZK. Techno-economic analysis of dynamic, end-to-end optimal pharmaceutical campaign manufacturing using PharmaPy. AIChE J 2023; 69:e18142. [PMID: 38179085 PMCID: PMC10765457 DOI: 10.1002/aic.18142] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 04/16/2023] [Indexed: 01/06/2024]
Abstract
Increased interest in the pharmaceutical industry to transition from batch to continuouos manufacturing motivates the use of digital frameworks that allow systematic comparison of candidate process configurations. This paper evaluates the technical and economic feasibility of different end-to-end optimal process configurations, viz. batch, hybrid and continuous, for small-scale manufacturing of an active pharmaceutical ingredient. Production campaigns were analyzed for those configurations containing continuous equipment, where significant start-up effects are expected given the relatively short campaign times considered. Hybrid operating mode was found to be the most attractive process configuration at intermediate and large annual production targets, which stems from combining continuous reactors and semi-batch vaporization equipment. Continuous operation was found to be more costly, due to long stabilization times of continuous crystallization, and thermodynamic limitations of flash vaporization. Our work reveals the benefits of systematic digital evaluation of process configurations that operate under feasible conditions and compliant product quality attributes.
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Affiliation(s)
- Daniel Casas-Orozco
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Daniel Laky
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Vivian Wang
- Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food & Drug Administration, Silver Spring, MD, USA
| | - Mesfin Abdi
- Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food & Drug Administration, Silver Spring, MD, USA
| | - X Feng
- Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food & Drug Administration, Silver Spring, MD, USA
| | - E Wood
- Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food & Drug Administration, Silver Spring, MD, USA
| | - Gintaras V Reklaitis
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Zoltan K Nagy
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47906, USA
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4
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Nagy BS, Fu G, Hone CA, Kappe CO, Ötvös SB. Harnessing a Continuous-Flow Persulfuric Acid Generator for Direct Oxidative Aldehyde Esterifications. CHEMSUSCHEM 2023; 16:e202201868. [PMID: 36377674 PMCID: PMC10107610 DOI: 10.1002/cssc.202201868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 10/30/2022] [Indexed: 06/16/2023]
Abstract
Persulfuric acid is a well-known oxidant in various industrial-scale purification procedures. However, due to its tendency toward explosive decomposition, its usefulness in organic synthesis remained largely underexplored. Herein, a continuous in situ persulfuric acid generator was developed and applied for oxidative esterification of aldehydes under flow conditions. Sulfuric acid served as a readily available and benign precursor to form persulfuric acid in situ. By taking advantage of the continuous-flow generator concept, safety hazards were significantly reduced, whilst a robust and effective approach was ensured for direct transformations of aldehydes to valuable esters. The process proved useful for the transformation of diverse aliphatic as well as aromatic aldehydes, while its preparative capability was verified by the multigram-scale synthesis of a pharmaceutically relevant key intermediate. The present flow protocol demonstrates the safe, sustainable, and scalable application of persulfuric acid in a manner that would not be amenable to conventional batch processing.
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Affiliation(s)
- Bence S. Nagy
- Institute of ChemistryUniversity of GrazNAWI GrazHeinrichstrasse 28A-8010GrazAustria
| | - Gang Fu
- Institute of ChemistryUniversity of GrazNAWI GrazHeinrichstrasse 28A-8010GrazAustria
| | - Christopher A. Hone
- Institute of ChemistryUniversity of GrazNAWI GrazHeinrichstrasse 28A-8010GrazAustria
- Center for Continuous Flow Synthesis and Processing (CC FLOW)Research CenterPharmaceutical Engineering GmbH (RCPE)Inffeldgasse 13A-8010GrazAustria
| | - C. Oliver Kappe
- Institute of ChemistryUniversity of GrazNAWI GrazHeinrichstrasse 28A-8010GrazAustria
- Center for Continuous Flow Synthesis and Processing (CC FLOW)Research CenterPharmaceutical Engineering GmbH (RCPE)Inffeldgasse 13A-8010GrazAustria
| | - Sándor B. Ötvös
- Institute of ChemistryUniversity of GrazNAWI GrazHeinrichstrasse 28A-8010GrazAustria
- Center for Continuous Flow Synthesis and Processing (CC FLOW)Research CenterPharmaceutical Engineering GmbH (RCPE)Inffeldgasse 13A-8010GrazAustria
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5
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Sokov SA, Odin IS, Zlotski SS, Denisova AG, Golovanov AA. Reactions of Activated Enynes with Diazomethane. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2021. [DOI: 10.1134/s107042802110002x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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6
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Menchikov LG, Shulishov EV, Tomilov YV. Recent advances in the catalytic cyclopropanation of unsaturated compounds with diazomethane. RUSSIAN CHEMICAL REVIEWS 2021. [DOI: 10.1070/rcr4982] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The main achievements and development trends of the past 10–15 years related to the catalytic cyclopropanation of unsaturated compounds with diazomethane are integrated and analyzed. The attention is focused on the most efficient catalysts based on palladium compounds. Data on the effects of substrate structure and nature of catalyst components on the regio- and stereoselectivity of these reactions are systematized. Characteristic features of safe methods for diazomethane generation are considered, including the use of membrane technologies and continuous-flow and in situ preparation methods, which have prospects for industrial application.
The bibliography includes 281 references.
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7
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Sheeran JW, Campbell K, Breen CP, Hummel G, Huang C, Datta A, Boyer SH, Hecker SJ, Bio MM, Fang YQ, Ford DD, Russell MG. Scalable On-Demand Production of Purified Diazomethane Suitable for Sensitive Catalytic Reactions. Org Process Res Dev 2020. [DOI: 10.1021/acs.oprd.0c00485] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | - Gerald Hummel
- Snapdragon Chemistry, Waltham, Massachusetts 02451, United States
| | - Changfeng Huang
- Snapdragon Chemistry, Waltham, Massachusetts 02451, United States
| | - Anamika Datta
- Snapdragon Chemistry, Waltham, Massachusetts 02451, United States
| | - Serge H. Boyer
- Qpex Biopharma, Inc., San Diego, California 92121, United States
| | - Scott J. Hecker
- Qpex Biopharma, Inc., San Diego, California 92121, United States
| | - Matthew M. Bio
- Snapdragon Chemistry, Waltham, Massachusetts 02451, United States
| | - Yuan-Qing Fang
- Snapdragon Chemistry, Waltham, Massachusetts 02451, United States
| | - David D. Ford
- Snapdragon Chemistry, Waltham, Massachusetts 02451, United States
| | - M. Grace Russell
- Snapdragon Chemistry, Waltham, Massachusetts 02451, United States
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8
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Abstract
Photochemical transformations of molecular building blocks have become an important and widely recognized research field in the past decade. Detailed and deep understanding of novel photochemical catalysts and reaction concepts with visible light as the energy source has enabled a broad application portfolio for synthetic organic chemistry. In parallel, continuous-flow chemistry and microreaction technology have become the basis for thinking and doing chemistry in a novel fashion with clear focus on improved process control for higher conversion and selectivity. As can be seen by the large number of scientific publications on flow photochemistry in the recent past, both research topics have found each other as exceptionally well-suited counterparts with high synergy by combining chemistry and technology. This review will give an overview on selected reaction classes, which represent important photochemical transformations in synthetic organic chemistry, and which benefit from mild and defined process conditions by the transfer from batch to continuous-flow mode.
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Affiliation(s)
- Thomas H. Rehm
- Division Energy & Chemical Technology/Flow Chemistry GroupFraunhofer Institute for Microengineering and Microsystems IMMCarl-Zeiss-Straße 18–2055129MainzGermany
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9
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Hatridge TA, Liu W, Yoo C, Davies HML, Jones CW. Optimized Immobilization Strategy for Dirhodium(II) Carboxylate Catalysts for C−H Functionalization and Their Implementation in a Packed Bed Flow Reactor. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202005381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Taylor A. Hatridge
- School of Chemical & Biomolecular Engineering Georgia Institute of Technology 311 Ferst Dr Atlanta GA 30332 USA
| | - Wenbin Liu
- Department of Chemistry Emory University 1515 Dickey Drive Atlanta GA 30322 USA
| | - Chun‐Jae Yoo
- School of Chemical & Biomolecular Engineering Georgia Institute of Technology 311 Ferst Dr Atlanta GA 30332 USA
| | - Huw M. L. Davies
- Department of Chemistry Emory University 1515 Dickey Drive Atlanta GA 30322 USA
| | - Christopher W. Jones
- School of Chemical & Biomolecular Engineering Georgia Institute of Technology 311 Ferst Dr Atlanta GA 30332 USA
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10
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Hatridge TA, Liu W, Yoo CJ, Davies HML, Jones CW. Optimized Immobilization Strategy for Dirhodium(II) Carboxylate Catalysts for C-H Functionalization and Their Implementation in a Packed Bed Flow Reactor. Angew Chem Int Ed Engl 2020; 59:19525-19531. [PMID: 32483912 DOI: 10.1002/anie.202005381] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/27/2020] [Indexed: 12/22/2022]
Abstract
Herein we demonstrate a packed bed flow reactor capable of achieving highly regio- and stereoselective C-H functionalization reactions using a newly developed Rh2 (S-2-Cl-5-CF3 TPCP)4 catalyst. To optimize the immobilized dirhodium catalyst employed in the flow reactor, we systematically study both (i) the effects of ligand immobilization position, demonstrating the critical factor that the catalyst-support attachment location can have on the catalyst performance, and (ii) silica support mesopore length, demonstrating that decreasing diffusional limitations leads to increased accessibility of the active site and higher catalyst turnover frequency. We employ the immobilized dirhodium catalyst in a simple packed bed flow reactor achieving comparable yields and levels of enantioselectivity to the homogeneous catalyst employed in batch and maintain this performance over ten catalyst recycles.
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Affiliation(s)
- Taylor A Hatridge
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr, Atlanta, GA, 30332, USA
| | - Wenbin Liu
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA, 30322, USA
| | - Chun-Jae Yoo
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr, Atlanta, GA, 30332, USA
| | - Huw M L Davies
- Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, GA, 30322, USA
| | - Christopher W Jones
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr, Atlanta, GA, 30332, USA
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11
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Hone CA, Kappe CO. Membrane Microreactors for the On-Demand Generation, Separation, and Reaction of Gases. Chemistry 2020; 26:13108-13117. [PMID: 32515835 PMCID: PMC7692882 DOI: 10.1002/chem.202001942] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/08/2020] [Indexed: 11/25/2022]
Abstract
The use of gases as reagents in organic synthesis can be very challenging, particularly at a laboratory scale. This Concept takes into account recent studies to make the case that gases can indeed be efficiently and safely formed from relatively inexpensive commercially available reagents for use in a wide range of organic transformations. In particular, we argue that the exploitation of continuous flow membrane reactors enables the effective separation of the chemistry necessary for gas formation from the chemistry for gas consumption, with these two stages often containing incompatible chemistry. The approach outlined eliminates the need to store and transport excessive amounts of potentially toxic, reactive or explosive gases. The on‐demand generation, separation and reaction of a number of gases, including carbon monoxide, diazomethane, trifluoromethyl diazomethane, hydrogen cyanide, ammonia and formaldehyde, is discussed.
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Affiliation(s)
- Christopher A Hone
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, 8010, Graz, Austria.,Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, 8010, Graz, Austria
| | - C Oliver Kappe
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, 8010, Graz, Austria.,Institute of Chemistry, University of Graz, NAWI Graz, Heinrichstrasse 28, 8010, Graz, Austria
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12
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Sinclair J, Dai G, McDonald R, Ferguson MJ, Brown A, Rivard E. Insight into the Decomposition Mechanism of Donor-Acceptor Complexes of EH 2 (E = Ge and Sn) and Access to Germanium Thin Films from Solution. Inorg Chem 2020; 59:10996-11008. [PMID: 32686404 DOI: 10.1021/acs.inorgchem.0c01492] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Electron-donating N-heterocyclic carbenes (Lewis bases, LB) and electron-accepting Lewis acids (LA) have been used in tandem to yield donor-acceptor complexes of inorganic tetrelenes LB·EH2·LA (E = Si, Ge, and Sn). Herein, we introduce the new germanium (II) dihydride adducts ImMe2·GeH2·BH3 (ImMe2 = (HCNMe)2C:) and ImiPr2Me2·GeH2·BH3 (ImiPr2Me2 = (MeCNiPr)2C:), with the former complex containing nearly 40 wt % germanium. The thermal release of bulk germanium from ImMe2·GeH2·BH3 (and its deuterated isotopologue ImMe2·GeD2·BD3) was examined in solution, and a combined kinetic and computational investigation was undertaken to probe the mechanism by which Ge is liberated. Moreover, the thermolysis of ImMe2·GeH2·BH3 in solution cleanly affords conformal nanodimensional layers of germanium as thin films of variable thicknesses (20-70 nm) on silicon wafers. We also conducted a computational investigation into potential decomposition pathways for the germanium(II)- and tin(II)-dihydride complexes NHC·EH2·BH3 (NHC = [(HCNR)2C:]; R = 2,6-iPr2C6H3 (Dipp), Me, and H; and E = Ge and Sn). Overall, this study introduces a mild and convenient solution-only protocol for the deposition of thin films of Ge, a widely used semiconductor in materials research and industry.
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Affiliation(s)
- Jocelyn Sinclair
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Guoliang Dai
- School of Chemistry, Biology and Materials Engineering, Suzhou University of Science and Technology, 2215009 Suzhou, P. R. China
| | - Robert McDonald
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Michael J Ferguson
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Alex Brown
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, Canada T6G 2G2
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Dallinger D, Gutmann B, Kappe CO. The Concept of Chemical Generators: On-Site On-Demand Production of Hazardous Reagents in Continuous Flow. Acc Chem Res 2020; 53:1330-1341. [PMID: 32543830 PMCID: PMC7467564 DOI: 10.1021/acs.accounts.0c00199] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
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In recent years, a steadily growing number of chemists, from both
academia and industry, have dedicated their research to the development
of continuous flow processes performed in milli- or microreactors.
The common availability of continuous flow equipment at virtually
all scales and affordable cost has additionally impacted this trend.
Furthermore, regulatory agencies such as the United States Food and
Drug Administration actively encourage continuous manufacturing of
active pharmaceutical ingredients (APIs) with the vision of quality
and productivity improvements. That is why the pharmaceutical industry
is progressively implementing continuous flow technologies. As a result
of the exceptional characteristics of continuous flow reactors such
as small reactor volumes and remarkably fast heat and mass transfer,
process conditions which need to be avoided in conventional batch
syntheses can be safely employed. Thus, continuous operation is particularly
advantageous for reactions at high temperatures/pressures (novel process
windows) and for ultrafast, exothermic reactions (flash chemistry). In addition to conditions that are outside of the operation range
of conventional stirred tank reactors, reagents possessing a high
hazard potential and therefore not amenable to batch processing can
be safely utilized (forbidden chemistry). Because of the small reactor
volumes, risks in case of a failure are minimized. Such hazardous
reagents often are low molecular weight compounds, leading generally
to the most atom-, time-, and cost-efficient route toward the desired
product. Ideally, they are generated from benign, readily available
and cheap precursors within the closed environment of the flow reactor
on-site on-demand. By doing so, the transport, storage, and handling
of those compounds, which impose a certain safety risk especially
on a large scale, are circumvented. This strategy also positively
impacts the global supply chain dependency, which can be a severe
issue, particularly in times of stricter safety regulations or an
epidemic. The concept of the in situ production of a hazardous material
is generally referred to as the “generator” of the material.
Importantly, in an integrated flow process, multiple modules can be
assembled consecutively, allowing not only an in-line purification/separation
and quenching of the reagent, but also its downstream conversion to
a nonhazardous product. For the past decade, research in our
group has focused on the continuous
generation of hazardous reagents using a range of reactor designs
and experimental techniques, particularly toward the synthesis of
APIs. In this Account, we therefore introduce chemical generator concepts
that have been developed in our laboratories for the production of
toxic, explosive, and short-lived reagents. We have defined three
different classes of generators depending on the reactivity/stability
of the reagents, featuring reagents such as Br2, HCN, peracids,
diazomethane (CH2N2), or hydrazoic acid (HN3). The various reactor designs, including in-line membrane
separation techniques and real-time process analytical technologies
for the generation, purification, and monitoring of those hazardous
reagents, and also their downstream transformations are presented.
This Account should serve as food for thought to extend the scope
of chemical generators for accomplishing more efficient and more economic
processes.
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Affiliation(s)
- Doris Dallinger
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, 8010 Graz, Austria
- Institute of Chemistry, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | - Bernhard Gutmann
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, 8010 Graz, Austria
- Institute of Chemistry, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | - C. Oliver Kappe
- Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE), Inffeldgasse 13, 8010 Graz, Austria
- Institute of Chemistry, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
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14
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Green S, Wheelhouse KM, Payne AD, Hallett JP, Miller PW, Bull JA. Thermal Stability and Explosive Hazard Assessment of Diazo Compounds and Diazo Transfer Reagents. Org Process Res Dev 2020; 24:67-84. [PMID: 31983869 PMCID: PMC6972035 DOI: 10.1021/acs.oprd.9b00422] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Indexed: 11/29/2022]
Abstract
Despite their wide use in academia as metal-carbene precursors, diazo compounds are often avoided in industry owing to concerns over their instability, exothermic decomposition, and potential explosive behavior. The stability of sulfonyl azides and other diazo transfer reagents is relatively well understood, but there is little reliable data available for diazo compounds. This work first collates available sensitivity and thermal analysis data for diazo transfer reagents and diazo compounds to act as an accessible reference resource. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and accelerating rate calorimetry (ARC) data for the model donor/acceptor diazo compound ethyl (phenyl)diazoacetate are presented. We also present a rigorous DSC dataset with 43 other diazo compounds, enabling direct comparison to other energetic materials to provide a clear reference work to the academic and industrial chemistry communities. Interestingly, there is a wide range of onset temperatures (T onset) for this series of compounds, which varied between 75 and 160 °C. The thermal stability variation depends on the electronic effect of substituents and the amount of charge delocalization. A statistical model is demonstrated to predict the thermal stability of differently substituted phenyl diazoacetates. A maximum recommended process temperature (T D24) to avoid decomposition is estimated for selected diazo compounds. The average enthalpy of decomposition (ΔH D) for diazo compounds without other energetic functional groups is -102 kJ mol-1. Several diazo transfer reagents are analyzed using the same DSC protocol and found to have higher thermal stability, which is in general agreement with the reported values. For sulfonyl azide reagents, an average ΔH D of -201 kJ mol-1 is observed. High-quality thermal data from ARC experiments shows the initiation of decomposition for ethyl (phenyl)diazoacetate to be 60 °C, compared to that of 100 °C for the common diazo transfer reagent p-acetamidobenzenesulfonyl azide (p-ABSA). The Yoshida correlation is applied to DSC data for each diazo compound to provide an indication of both their impact sensitivity (IS) and explosivity. As a neat substance, none of the diazo compounds tested are predicted to be explosive, but many (particularly donor/acceptor diazo compounds) are predicted to be impact-sensitive. It is therefore recommended that manipulation, agitation, and other processing of neat diazo compounds are conducted with due care to avoid impacts, particularly in large quantities. The full dataset is presented to inform chemists of the nature and magnitude of hazards when using diazo compounds and diazo transfer reagents. Given the demonstrated potential for rapid heat generation and gas evolution, adequate temperature control and cautious addition of reagents that begin a reaction are strongly recommended when conducting reactions with diazo compounds.
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Affiliation(s)
- Sebastian
P. Green
- Department
of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, 80 Wood Lane, London W12 0BZ, U.K.
- Department
of Chemical Engineering, Imperial College
London, South Kensington Campus, Exhibition Road, London SW7 2AZ, U.K.
| | - Katherine M. Wheelhouse
- API Chemistry, Product Development & Supply and Process Safety,
Pilot Plant Operations, GlaxoSmithKline,
GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K.
| | - Andrew D. Payne
- API Chemistry, Product Development & Supply and Process Safety,
Pilot Plant Operations, GlaxoSmithKline,
GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K.
| | - Jason P. Hallett
- Department
of Chemical Engineering, Imperial College
London, South Kensington Campus, Exhibition Road, London SW7 2AZ, U.K.
| | - Philip W. Miller
- Department
of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, 80 Wood Lane, London W12 0BZ, U.K.
| | - James A. Bull
- Department
of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, 80 Wood Lane, London W12 0BZ, U.K.
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15
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Djordjevic I, Wicaksono G, Solic I, Steele TW. Diazoalkane decay kinetics from UVA-active protein labelling molecules: Trifluoromethyl phenyl diazirines. RESULTS IN CHEMISTRY 2020. [DOI: 10.1016/j.rechem.2020.100066] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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16
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Understanding of two-stage continuous microreaction technology for in-situ generation and consecutive conversion of diazomethane. J Taiwan Inst Chem Eng 2019. [DOI: 10.1016/j.jtice.2018.06.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Bogdan AR, Dombrowski AW. Emerging Trends in Flow Chemistry and Applications to the Pharmaceutical Industry. J Med Chem 2019; 62:6422-6468. [DOI: 10.1021/acs.jmedchem.8b01760] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Andrew R. Bogdan
- Discovery Chemistry and Technology, AbbVie, Inc. 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Amanda W. Dombrowski
- Discovery Chemistry and Technology, AbbVie, Inc. 1 North Waukegan Road, North Chicago, Illinois 60064, United States
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18
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Chen Y. Recent Advances in Methylation: A Guide for Selecting Methylation Reagents. Chemistry 2018; 25:3405-3439. [DOI: 10.1002/chem.201803642] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Yantao Chen
- Medicinal Chemistry, Cardiovascular, Renal and Metabolism, IMED Biotech UnitAstraZeneca Gothenburg Sweden
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19
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Akwi FM, Watts P. Continuous flow chemistry: where are we now? Recent applications, challenges and limitations. Chem Commun (Camb) 2018; 54:13894-13928. [PMID: 30483683 DOI: 10.1039/c8cc07427e] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A general outlook of the changing face of chemical synthesis is provided in this article through recent applications of continuous flow processing in both industry and academia. The benefits, major challenges and limitations associated with the use of this mode of processing are also given due attention as an attempt to put into perspective the current position of continuous flow processing, either as an alternative or potential combinatory technology for batch processing.
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Affiliation(s)
- Faith M Akwi
- Nelson Mandela University, University Way, Port Elizabeth, 6031, South Africa.
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20
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McWilliams JC, Allian AD, Opalka SM, May SA, Journet M, Braden TM. The Evolving State of Continuous Processing in Pharmaceutical API Manufacturing: A Survey of Pharmaceutical Companies and Contract Manufacturing Organizations. Org Process Res Dev 2018. [DOI: 10.1021/acs.oprd.8b00160] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- J. Christopher McWilliams
- Chemical Research and Development, Pfizer Worldwide Research and Development, Eastern Point Road, Groton, Connecticut 06340, United States
| | - Ayman D. Allian
- Department of Pivotal Drug Substance Technologies, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
| | - Suzanne M. Opalka
- Chemical Process Development, Biogen Idec, 115 Broadway, Cambridge, Massachusetts 02142, United States
| | - Scott A. May
- Small Molecule Design and Development, Eli Lilly and Company, Indianapolis, Indiana 46285, United States
| | - Michel Journet
- API Chemistry, GSK, 709 Swedeland Road, UW2810, P.O. Box 1539, King of Prussia, Pennsylvania 19406, United States
| | - Timothy M. Braden
- Small Molecule Design and Development, Eli Lilly and Company, Indianapolis, Indiana 46285, United States
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21
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Yoo C, Rackl D, Liu W, Hoyt CB, Pimentel B, Lively RP, Davies HML, Jones CW. An Immobilized‐Dirhodium Hollow‐Fiber Flow Reactor for Scalable and Sustainable C−H Functionalization in Continuous Flow. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201805528] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Chun‐Jae Yoo
- School of Chemical & Biomolecular Engineering Department Georgia Institute of Technology 311 Ferst Drive NW Atlanta GA 30332 USA
| | - Daniel Rackl
- Department of Chemistry Emory University 1515 Dickey Drive Atlanta GA 30322 USA
| | - Wenbin Liu
- Department of Chemistry Emory University 1515 Dickey Drive Atlanta GA 30322 USA
| | - Caroline B. Hoyt
- School of Chemical & Biomolecular Engineering Department Georgia Institute of Technology 311 Ferst Drive NW Atlanta GA 30332 USA
| | - Brian Pimentel
- School of Chemical & Biomolecular Engineering Department Georgia Institute of Technology 311 Ferst Drive NW Atlanta GA 30332 USA
| | - Ryan P. Lively
- School of Chemical & Biomolecular Engineering Department Georgia Institute of Technology 311 Ferst Drive NW Atlanta GA 30332 USA
| | - Huw M. L. Davies
- Department of Chemistry Emory University 1515 Dickey Drive Atlanta GA 30322 USA
| | - Christopher W. Jones
- School of Chemical & Biomolecular Engineering Department Georgia Institute of Technology 311 Ferst Drive NW Atlanta GA 30332 USA
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22
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Yoo C, Rackl D, Liu W, Hoyt CB, Pimentel B, Lively RP, Davies HML, Jones CW. An Immobilized‐Dirhodium Hollow‐Fiber Flow Reactor for Scalable and Sustainable C−H Functionalization in Continuous Flow. Angew Chem Int Ed Engl 2018; 57:10923-10927. [DOI: 10.1002/anie.201805528] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 06/18/2018] [Indexed: 01/07/2023]
Affiliation(s)
- Chun‐Jae Yoo
- School of Chemical & Biomolecular Engineering Department Georgia Institute of Technology 311 Ferst Drive NW Atlanta GA 30332 USA
| | - Daniel Rackl
- Department of Chemistry Emory University 1515 Dickey Drive Atlanta GA 30322 USA
| | - Wenbin Liu
- Department of Chemistry Emory University 1515 Dickey Drive Atlanta GA 30322 USA
| | - Caroline B. Hoyt
- School of Chemical & Biomolecular Engineering Department Georgia Institute of Technology 311 Ferst Drive NW Atlanta GA 30332 USA
| | - Brian Pimentel
- School of Chemical & Biomolecular Engineering Department Georgia Institute of Technology 311 Ferst Drive NW Atlanta GA 30332 USA
| | - Ryan P. Lively
- School of Chemical & Biomolecular Engineering Department Georgia Institute of Technology 311 Ferst Drive NW Atlanta GA 30332 USA
| | - Huw M. L. Davies
- Department of Chemistry Emory University 1515 Dickey Drive Atlanta GA 30322 USA
| | - Christopher W. Jones
- School of Chemical & Biomolecular Engineering Department Georgia Institute of Technology 311 Ferst Drive NW Atlanta GA 30332 USA
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