1
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Effect of initiator on the catalytic performance of zinc(II) complexes supported by aminomethylquinoline and aminomethylpyridine derived ligands in stereoselective ring opening polymerization of rac-lactide. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.115696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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2
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Dordahan F, Schaper F. Lactide polymerization using a sterically encumbered, flexible zinc complex. CAN J CHEM 2021. [DOI: 10.1139/cjc-2021-0239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
4-(tert-Butyl)-2-trityl-6-(di-(2-picolyl)amine)phenol, LH, was prepared from paraformaldehyde, 4-(tert-butyl)-2-tritylphenol and di-(2-picolyl)amine. Reaction with Zn(N(SiMe3)2)2 gave LZnN(SiMe3)2. The complex was shown by X-ray diffraction study, variable
temperature NMR and DFT calculations to coordinate only one pyridine ligand, which allows for fast and facile complex isomerisation. LZnN(SiMe3)2 was active in rac-lactide polymerization, but in contrast to previous complexes of this type did not show any evidence for isotactic monomer enchainment via a catalytic-site mediated chain-end control mechanism. Addition of alcohol led to increased activity, but the complex was unstable in the presence of free alcohol.
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Affiliation(s)
- Fatemeh Dordahan
- Université de Montréal, 5622, Chemistry, Montreal, Quebec, Canada
| | - Frank Schaper
- Université de Montréal, 5622, Chemistry, Montreal, Quebec, Canada,
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3
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Polymetallic Group 4 Complexes: Catalysts for the Ring Opening Polymerisation of rac-Lactide. Catalysts 2021. [DOI: 10.3390/catal11050551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Five novel air- and moisture-stable polymetallic Ti and Zr amino acid-derived amine bis(phenolate) (ABP) complexes were synthesised and fully characterised, including X-ray crystallographic studies. The reaction of the ABP proligands with Ti or Zr alkoxides has resulted in the formation of polymetallic aggregates of different nuclearity. The steric bulk on the pendant arm of the ligand was found to play a critical role in establishing the nuclearity of the aggregated complex. Sterically, less-demanding groups, such as H or Me, facilitated the formation of tetrametallic Ti clusters, bridged by carboxylate groups, while increased steric bulk (tBu) led to the formation of binuclear μ-oxo-bridged species. The isolated complexes were employed as catalysts for the ring opening polymerisation (ROP) of rac-lactide. Overall, the Ti catalysts were all active with the smaller, bimetallic Ti aggregates exhibiting relatively faster rates. A monometallic, bis(ABP) Zr complex was found to exert remarkable ROP activity, albeit with limited control over the tacticity and molecular weight distribution of the polymer. A further oxo-bridged Zr cluster was shown to display a previously unprecedented trimetallic structure and achieved a moderate rate in the ROP of rac-lactide.
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4
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Alshamrani AFA, Santoro O, Ounsworth S, Prior TJ, Stasiuk GJ, Redshaw C. Synthesis, characterisation and ROP catalytic evaluation of Cu(II) complexes bearing 2,2ʹ-diphenylglycine-derived moieties. Polyhedron 2021. [DOI: 10.1016/j.poly.2020.114977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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5
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Balint A, Naumann S. A comparison of zwitterionic and anionic mechanisms in the dual-catalytic polymerization of lactide. Polym Chem 2021. [DOI: 10.1039/d1py00992c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Two different polymerization mechanisms for lactide are selectivity addressed to illuminate the respective role of organobase and Lewis acid component.
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Affiliation(s)
- Alexander Balint
- University of Stuttgart, Institute of Polymer Chemistry, 70569 Stuttgart, Germany
| | - Stefan Naumann
- University of Stuttgart, Institute of Polymer Chemistry, 70569 Stuttgart, Germany
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6
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Fang C, Ma H. Ring-opening polymerization of rac-lactide, copolymerization of rac-lactide and ε-caprolactone by zinc complexes bearing pyridyl-based tridentate amino-phenolate ligands. Eur Polym J 2019. [DOI: 10.1016/j.eurpolymj.2019.07.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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7
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Hardouin Duparc V, Dimeck C, Schaper F. Replacing sulfonate by carboxylate: application of pyridyliminocarboxylato copper(II) complexes in rac-lactide polymerization and Chan–Evans–Lam coupling. CAN J CHEM 2019. [DOI: 10.1139/cjc-2018-0402] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Copper(II) complexes carrying pyridylmethyleneaminobenzoate or –propanoate ligands, LCuX, were prepared in one-pot reactions from pyridinecarboxaldehyde, aminobenzoic acid or β-alanine, and CuX2 (X = Cl, NO3, OAc, or OTf). All complexes were characterized by single-crystal X-ray diffraction studies and formed either dimers, tetramers, or coordination polymers. Attempted preparation of the respective alkoxide complexes, LCu(OR), was unsuccessful, but use of LCuX/NaOMe mixtures in rac-lactide polymerization indicated under some conditions coordination–insertion polymerization via a copper alkoxide as the mechanism. The complexes performed poorly in rac-lactide polymerization, showing low activities (12 h to completion at 140 °C), low to moderate heterotacticity (Pr = 0.6–0.8), and poor polymer molecular weight control (intramolecular transesterification). They were competent catalysts for Chan–Evans–Lam couplings with phenylboronic acid, without any indication of side reactions such as deboration or aryl homocoupling. The complexes were active in undried methanol, without addition of base, ligand, or molecular sieves. Aniline, n-octylamine, and cyclohexylamine were coupled quantitatively under identical reaction conditions. There is only little influence of the anion on activities (less than a factor of 2) but a strong influence on induction periods. The complexes were not active in CEL coupling with alcohols, phenols, or alkylboronic acids.
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Affiliation(s)
- Valérie Hardouin Duparc
- Centre in Green Chemistry and Catalysis, Département de chimie, Université de Montréal, 2900 Boul. E.-Montpetit, Montréal, QC H3T 1J4, Canada
- Centre in Green Chemistry and Catalysis, Département de chimie, Université de Montréal, 2900 Boul. E.-Montpetit, Montréal, QC H3T 1J4, Canada
| | - Clémentine Dimeck
- Centre in Green Chemistry and Catalysis, Département de chimie, Université de Montréal, 2900 Boul. E.-Montpetit, Montréal, QC H3T 1J4, Canada
- Centre in Green Chemistry and Catalysis, Département de chimie, Université de Montréal, 2900 Boul. E.-Montpetit, Montréal, QC H3T 1J4, Canada
| | - Frank Schaper
- Centre in Green Chemistry and Catalysis, Département de chimie, Université de Montréal, 2900 Boul. E.-Montpetit, Montréal, QC H3T 1J4, Canada
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8
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Kremer AB, Mehrkhodavandi P. Dinuclear catalysts for the ring opening polymerization of lactide. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2018.09.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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9
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Li M, Behzadi S, Chen M, Pang W, Wang F, Tan C. Phenoxyimine Ligands Bearing Nitrogen-Containing Second Coordination Spheres for Zinc Catalyzed Stereoselective Ring-Opening Polymerization of rac-Lactide. Organometallics 2019. [DOI: 10.1021/acs.organomet.8b00788] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Min Li
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, People’s Republic of China
| | - Shabnam Behzadi
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, People’s Republic of China
| | - Min Chen
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, People’s Republic of China
| | - Wenmin Pang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, People’s Republic of China
| | - Fuzhou Wang
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230026, People’s Republic of China
| | - Chen Tan
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, People’s Republic of China
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Harinath A, Bhattacharjee J, Sarkar A, Panda TK. Alkali metal complex-mediated ring-opening polymerization of rac-LA, ε-caprolactone, and δ-valerolactone. NEW J CHEM 2019. [DOI: 10.1039/c9nj01130g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Catalytic ring opening polymerization (ROP) of rac-lactide, ε-caprolactone, and δ-valerolactone using alkali metal (Li, Na, K) complexes as competent catalysts are reported.
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Affiliation(s)
- Adimulam Harinath
- Department of Chemistry
- Indian Institute of Technology Hyderabad Kandi – 502 285
- Sangareddy
- India
| | - Jayeeta Bhattacharjee
- Department of Chemistry
- Indian Institute of Technology Hyderabad Kandi – 502 285
- Sangareddy
- India
| | - Alok Sarkar
- Momentive Performance Materials Pvt. Ltd
- Bangalore – 560 100
- India
| | - Tarun K. Panda
- Department of Chemistry
- Indian Institute of Technology Hyderabad Kandi – 502 285
- Sangareddy
- India
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11
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Peewasan K, Merkel MP, Zarschler K, Stephan H, Anson CE, Powell AK. Tetranuclear Cu(ii)-chiral complexes: synthesis, characterization and biological activity. RSC Adv 2019; 9:24087-24091. [PMID: 35527904 PMCID: PMC9069531 DOI: 10.1039/c9ra03586a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 07/19/2019] [Indexed: 01/16/2023] Open
Abstract
A pair of tetranuclear chiral Cu(ii)-Schiff-base complexes were synthesized using enantiomerically pure (S)-H2L and (R)-H2L ligands. These were characterised using single-crystal X-ray diffraction and CD spectroscopy and their biological activity tested.
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Affiliation(s)
- Krisana Peewasan
- Institute of Inorganic Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
| | - Marcel P. Merkel
- Institute of Nanotechnology
- Karlsruhe Institute of Technology
- Karlsruhe
- Germany
| | - Kristof Zarschler
- Institute of Radiopharmaceutical Cancer Research
- Helmholtz-ZentrumDresden-Rossendorf
- D-01328 Dresden
- Germany
| | - Holger Stephan
- Institute of Radiopharmaceutical Cancer Research
- Helmholtz-ZentrumDresden-Rossendorf
- D-01328 Dresden
- Germany
| | - Christopher E. Anson
- Institute of Inorganic Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
| | - Annie K. Powell
- Institute of Inorganic Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
- Institute of Nanotechnology
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12
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Daneshmand P, Michalsky I, Aguiar PM, Schaper F. Configurationally flexible zinc complexes as catalysts for rac-lactide polymerisation. Dalton Trans 2018; 47:16279-16291. [DOI: 10.1039/c8dt02562b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introduction of catalytic site flexibility (fast racemisation) into a previously reported zinc alkoxide catalyst afforded a slight preference for isotactic lactide polymerization via catalytic-site mediated chain-end control.
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Affiliation(s)
- Pargol Daneshmand
- Centre in Green Chemistry and Catalysis
- Department of chemistry
- Université deMontréal
- Montréal
- Canada
| | - Ina Michalsky
- Centre in Green Chemistry and Catalysis
- Department of chemistry
- Université deMontréal
- Montréal
- Canada
| | - Pedro M. Aguiar
- Centre in Green Chemistry and Catalysis
- Department of chemistry
- Université deMontréal
- Montréal
- Canada
| | - Frank Schaper
- Centre in Green Chemistry and Catalysis
- Department of chemistry
- Université deMontréal
- Montréal
- Canada
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