1
|
Acosta-Calle S, Miller AJM. Tunable and Switchable Catalysis Enabled by Cation-Controlled Gating with Crown Ether Ligands. Acc Chem Res 2023; 56:971-981. [PMID: 36977400 DOI: 10.1021/acs.accounts.3c00056] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
ConspectusCatalysis has become an essential tool in science and technology, impacting the discovery of pharmaceuticals, the manufacture of commodity chemicals and plastics, the production of fuels, and much more. In most cases, a particular catalyst is optimized to mediate a particular reaction, continually producing a desired product at a given rate. There is enormous opportunity in developing catalysts that are dynamic, capable of responding to a change in the environment to alter structure and function. Controlled catalysis, in which the activity or selectivity of a catalytic reaction can be adjusted through an external stimulus, offers opportunities for innovation in catalysis. Catalyst discovery could be simplified if a single thoughtfully designed complex could work synergistically with additives to optimize performance rather than trying a multitude of different metal/ligand combinations. Temporal control could be gained to facilitate the execution of multiple reactions in the same flask, for example, by activating one catalyst and deactivating another to avoid incompatibilities. Selectivity switching could enable copolymer synthesis with well-defined chemical and material properties. These applications might sound futuristic for synthetic catalysts, but in nature, such a degree of controlled catalysis is commonplace. For example, allosteric interactions and/or feedback loops modulate enzymatic activity to enable complex small-molecule synthesis and sequence-defined polymerization reactions in complex mixtures containing many catalytic sites. In many cases, regulation is achieved by "gating" substrate access to the active site. Fundamental advances in catalyst design are needed to better understand the factors that enable controlled catalysis in the arena of synthetic chemistry, particularly in achieving substrate gating outside of macromolecular environments. In this Account, the development of design principles for achieving cation-controlled catalysis is described. The guiding hypothesis was that gating substrate access to a catalyst site could be achieved by controlling the dynamics of a hemilabile ligand through secondary Lewis acid/base and/or cation-dipole interactions. To enforce such interactions, catalysts sitting at the interface of organometallic catalysis and supramolecular chemistry were designed. A macrocyclic crown ether was incorporated into a robust organometallic pincer ligand, and these "pincer-crown ether" ligands have been explored in catalysis. Complementary studies of controlled catalysis and detailed mechanistic analysis guided the development of iridium, nickel, and palladium pincer-crown ether catalysts capable of substrate gating. Toggling the gate between open and closed states leads to switchable catalysis, where cation addition/removal changes the turnover frequency or the product selectivity. Varying the degree of gating leads to tunable catalysis, where the activity can be tuned based on the identity and amount of salt added. Research has focused on reactions of alkenes, particularly isomerization reactions, which has in turn led to design principles for cation-controlled catalysts.
Collapse
Affiliation(s)
- Sebastian Acosta-Calle
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Alexander J M Miller
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| |
Collapse
|
2
|
Farquhar AH, Gardner KE, Acosta-Calle S, Camp AM, Chen CH, Miller AJM. Cation-Controlled Olefin Isomerization Catalysis with Palladium Pincer Complexes. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexandra H. Farquhar
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Kristen E. Gardner
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Sebastian Acosta-Calle
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Andrew M. Camp
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Chun-Hsing Chen
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Alexander J. M. Miller
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| |
Collapse
|
3
|
Gordon BM, Parihar A, Hasanayn F, Goldman AS. High Activity and Selectivity for Catalytic Alkane–Alkene Transfer (De)hydrogenation by ( tBuPPP)Ir and the Importance of Choice of a Sacrificial Hydrogen Acceptor. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00401] [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)
- Benjamin M. Gordon
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Ashish Parihar
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Faraj Hasanayn
- Department of Chemistry, American University of Beirut, Beirut 1107 2020, Lebanon
| | - Alan S. Goldman
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| |
Collapse
|
4
|
Linke A, Decker D, Drexler HJ, Beweries T. Iridium(III) bis(thiophosphinite) pincer complexes: synthesis, ligand activation and applications in catalysis. Dalton Trans 2022; 51:10266-10271. [PMID: 35748648 DOI: 10.1039/d2dt01633h] [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
Iridium(III) bis(thiophosphinite) complexes of the type [(RPSCSPR)Ir(H)(Cl)(py)] (RPSCSPR = κ3-(2,6-SPR2)C6H3) (R = tBu, iPr, Ph) can be prepared from the ligand precursors 1,3-(SPR2)C6H4 by C-H activation at Ir using [Ir(COE)2Cl]2 or [Ir(COD)Cl]2. Optimisation of the protocol for complexation showed that direct cyclometallation in the absence or presence of pyridine, as well as C-H activation in the presence of H2 are viable options that, depending on the phosphine substituent furnish the five-coordinate Ir(III) hydride chloride complexes 2-R or the base stabilised species 3-R in good yields. In case of the PhPSCSPPh ligand, P-S activation results in the formation of a thiophosphine stabilised Ir(III) hydride complex [(PhPSCSPPh)Ir(H)(Cl)(PPh2SH)] (4). Reaction of 2-tBu with H2 in the presence of base furnishes an Ir(III) dihydride complex (5) via a labile Ir(III) dihydride-dihydrogen complex (6). All complexes are inactive for transfer dehydrogenation of cyclooctane in the presence of NaOtBu and tert-butylethylene, likely due to decomposition of the Ir complex in the presence of base at higher temperature.
Collapse
Affiliation(s)
- Alexander Linke
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| | - David Decker
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| | - Hans-Joachim Drexler
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| | - Torsten Beweries
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Str. 29a, 18059 Rostock, Germany.
| |
Collapse
|
5
|
Jiang B, Chen C, Fan G, Sang W, Cheng H, Zhang R, Yuan Y, Li Q, Verpoort F. Cs
2
CO
3
‐Promoted C−O Coupling Protocol Enables Solventless (Hetero)aryl Ether Synthesis under Air Atmosphere. Chem Asian J 2022; 17:e202101370. [DOI: 10.1002/asia.202101370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/13/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Bowen Jiang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology 122 Luoshi Road Wuhan 430070 P. R. China
| | - Cheng Chen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology 122 Luoshi Road Wuhan 430070 P. R. China
| | - Guang‐Gao Fan
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology 122 Luoshi Road Wuhan 430070 P. R. China
| | - Wei Sang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology 122 Luoshi Road Wuhan 430070 P. R. China
| | - Hua Cheng
- Department of Chemical Engineering and Food Science Hubei University of Arts and Science Xiangyang 441053 P. R. China
| | - Rui Zhang
- Department of Chemical Engineering and Food Science Hubei University of Arts and Science Xiangyang 441053 P. R. China
| | - Ye Yuan
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology 122 Luoshi Road Wuhan 430070 P. R. China
| | - Qi‐Zhong Li
- North China Institute of Science and Technology 467 Xueyuan street, East Yanjiao Beijing 101601 P. R. China
| | - Francis Verpoort
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology 122 Luoshi Road Wuhan 430070 P. R. China
- National Research Tomsk Polytechnic University Tomsk 634050 Russian Federation
- Ghent University Global Campus 119 Songdomunhwa-Ro, Yeonsu-Gu Incheon 21985 Korea
| |
Collapse
|
6
|
Dipyridylmethane Ethers as Ligands for Luminescent Ir Complexes. Molecules 2021; 26:molecules26237161. [PMID: 34885742 PMCID: PMC8659258 DOI: 10.3390/molecules26237161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 11/17/2022] Open
Abstract
This work reports two new cationic heteroleptic cyclometalated iridium complexes, containing ether derivatives of di(pyridin-2-yl)methanol. The new ligands are based on dipyridin-2-ylmethane and are designed to obtain ether-based intermediates with extended electronic conjugation by insertion of π system such as phenyl, allyl and ethynyl. Different synthetic strategies were employed to introduce these units, as molecular wires, between the dipyridin-2-ylmethane chelating portion and the terminal N-containing functional group, such as amine and carbamide. The corresponding complexes show luminescence in the blue region of the spectrum, lifetimes between 0.6 and 2.1 μs, high quantum yield and good electrochemical behavior. The computational description (DFT) of the electronic structure highlights the key role of the conjugated π systems on optical and electrochemical properties of the final products.
Collapse
|
7
|
Yoo C, Miller AJM. Stepwise Iodide-Free Methanol Carbonylation via Methyl Acetate Activation by Pincer Iridium Complexes. J Am Chem Soc 2021; 143:12633-12643. [PMID: 34347476 DOI: 10.1021/jacs.1c05185] [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
Iodide is an essential promoter in the industrial production of acetic acid via methanol carbonylation, but it also contributes to reactor corrosion and catalyst deactivation. Here we report that iridium pincer complexes mediate the individual steps of methanol carbonylation to methyl acetate in the absence of methyl iodide or iodide salts. Iodide-free methylation is achieved under mild conditions by an aminophenylphosphinite pincer iridium(I) dinitrogen complex through net C-O oxidative addition of methyl acetate to produce an isolable methyliridium(III) acetate complex. Experimental and computational studies provide evidence for methylation via initial C-H bond activation followed by acetate migration, facilitated by amine hemilability. Subsequent CO insertion and reductive elimination in methanol solution produced methyl acetate and acetic acid. The net reaction is methanol carbonylation to acetic acid using methyl acetate as a promoter alongside conversion of an iridium dinitrogen complex to an iridium carbonyl complex. Kinetic studies of migratory insertion and reductive elimination reveal essential roles of the solvent methanol and distinct features of acetate and iodide anions that are relevant to the design of future catalysts for iodide-free carbonylation.
Collapse
Affiliation(s)
- Changho Yoo
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.,Green Carbon Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea
| | - Alexander J M Miller
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| |
Collapse
|
8
|
Camp AM, Kita MR, Blackburn PT, Dodge HM, Chen CH, Miller AJM. Selecting Double Bond Positions with a Single Cation-Responsive Iridium Olefin Isomerization Catalyst. J Am Chem Soc 2021; 143:2792-2800. [DOI: 10.1021/jacs.0c11601] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew M. Camp
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599−3290, United States
| | - Matthew R. Kita
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599−3290, United States
| | - P. Thomas Blackburn
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599−3290, United States
| | - Henry M. Dodge
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599−3290, United States
| | - Chun-Hsing Chen
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599−3290, United States
| | - Alexander J. M. Miller
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599−3290, United States
| |
Collapse
|