1
|
Clarke RW, Sandmeier T, Franklin KA, Reich D, Zhang X, Vengallur N, Patra TK, Tannenbaum RJ, Adhikari S, Kumar SK, Rovis T, Chen EYX. Dynamic crosslinking compatibilizes immiscible mixed plastics. Nature 2023; 616:731-739. [PMID: 37100943 DOI: 10.1038/s41586-023-05858-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 02/16/2023] [Indexed: 04/28/2023]
Abstract
The global plastics problem is a trifecta, greatly affecting environment, energy and climate1-4. Many innovative closed/open-loop plastics recycling or upcycling strategies have been proposed or developed5-16, addressing various aspects of the issues underpinning the achievement of a circular economy17-19. In this context, reusing mixed-plastics waste presents a particular challenge with no current effective closed-loop solution20. This is because such mixed plastics, especially polar/apolar polymer mixtures, are typically incompatible and phase separate, leading to materials with substantially inferior properties. To address this key barrier, here we introduce a new compatibilization strategy that installs dynamic crosslinkers into several classes of binary, ternary and postconsumer immiscible polymer mixtures in situ. Our combined experimental and modelling studies show that specifically designed classes of dynamic crosslinker can reactivate mixed-plastics chains, represented here by apolar polyolefins and polar polyesters, by compatibilizing them via dynamic formation of graft multiblock copolymers. The resulting in-situ-generated dynamic thermosets exhibit intrinsic reprocessability and enhanced tensile strength and creep resistance relative to virgin plastics. This approach avoids the need for de/reconstruction and thus potentially provides an alternative, facile route towards the recovery of the endowed energy and materials value of individual plastics.
Collapse
Affiliation(s)
- Ryan W Clarke
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
| | | | - Kevin A Franklin
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA
| | - Dominik Reich
- Department of Chemistry, Columbia University, New York, NY, USA
| | - Xiao Zhang
- Department of Chemistry, Columbia University, New York, NY, USA
| | - Nayan Vengallur
- Department of Chemical Engineering, Center for Carbon Capture Utilization and Storage, and Center for Atomistic Modeling and Materials Design, India Institute of Technology Madras, Chennai, India
| | - Tarak K Patra
- Department of Chemical Engineering, Center for Carbon Capture Utilization and Storage, and Center for Atomistic Modeling and Materials Design, India Institute of Technology Madras, Chennai, India
| | | | - Sabin Adhikari
- Department of Chemical Engineering, Columbia University, New York, NY, USA
| | - Sanat K Kumar
- Department of Chemical Engineering, Columbia University, New York, NY, USA.
| | - Tomislav Rovis
- Department of Chemistry, Columbia University, New York, NY, USA.
| | - Eugene Y-X Chen
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA.
| |
Collapse
|
2
|
Eichler T, Rötz W, Kayser C, Bröhl F, Römer M, Witteborg AH, Kummert F, Sandmeier T, Schulte C, Stolz P, Meyer K, Sudhoff H, Todt I. Algorithm-Based Hearing and Speech Therapy Rehabilitation after Cochlear Implantation. Brain Sci 2022; 12:580. [PMID: 35624970 PMCID: PMC9139523 DOI: 10.3390/brainsci12050580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/14/2022] [Accepted: 04/21/2022] [Indexed: 12/04/2022] Open
Abstract
INTRODUCTION Due to the changes in the indication range for cochlear implants and the demographic development towards an aging society, more and more people are in receipt of cochlear implants. An implantation requires a close-meshed audiological and logopedic aftercare. Hearing therapy rehabilitation currently requires great personnel effort and is time consuming. Hearing and speech therapy rehabilitation can be supported by digital hearing training programs. However, the apps currently on the market are to a limited degree personalized and structured. Increasing digitalization makes it possible, especially in times of pandemics, to decouple hearing therapy treatment from everyday clinical practice. MATERIAL AND METHODS For this purpose, an app is in development that provides hearing therapy tailored to the patient. The individual factors that influence hearing outcome are considered. Using intelligent algorithms, the app determines the selection of exercises, the level of difficulty and the speed at which the difficulty is increased. RESULTS The app works autonomously without being connected to local speech therapists. In addition, the app is able to analyze patient difficulties within the exercises and provides conclusions about the need for technical adjustments. CONCLUSIONS The presented newly developed app represents a possibility to support, replace, expand and improve the classic outpatient hearing and speech therapy after CI implantation. The way the application works allows it to reach more people and provide a time- and cost-saving alternative to traditional therapy.
Collapse
Affiliation(s)
- Theda Eichler
- Department of Otolaryngology, Head and Neck Surgery, Medical School OWL, Campus Bielefeld Mitte, Bielefeld University, 33604 Bielefeld, Germany; (W.R.); (H.S.); (I.T.)
| | - Wiebke Rötz
- Department of Otolaryngology, Head and Neck Surgery, Medical School OWL, Campus Bielefeld Mitte, Bielefeld University, 33604 Bielefeld, Germany; (W.R.); (H.S.); (I.T.)
| | - Christoph Kayser
- Faculty of Biology, Cognitive Neuroscience, Bielefeld University, 33615 Bielefeld, Germany; (C.K.); (F.B.)
| | - Felix Bröhl
- Faculty of Biology, Cognitive Neuroscience, Bielefeld University, 33615 Bielefeld, Germany; (C.K.); (F.B.)
| | - Michael Römer
- Faculty of Economics, Decision Analytics, Bielefeld University, 33615 Bielefeld, Germany; (M.R.); (A.H.W.)
| | - Arne Henning Witteborg
- Faculty of Economics, Decision Analytics, Bielefeld University, 33615 Bielefeld, Germany; (M.R.); (A.H.W.)
| | - Franz Kummert
- Research Institute for Cognition and Robotics, Bielefeld University, 33615 Bielefeld, Germany; (F.K.); (T.S.); (C.S.)
| | - Tobias Sandmeier
- Research Institute for Cognition and Robotics, Bielefeld University, 33615 Bielefeld, Germany; (F.K.); (T.S.); (C.S.)
| | - Christoph Schulte
- Research Institute for Cognition and Robotics, Bielefeld University, 33615 Bielefeld, Germany; (F.K.); (T.S.); (C.S.)
| | - Patricia Stolz
- Department of Design, University of Applied Science, 33619 Bielefeld, Germany; (P.S.); (K.M.)
| | - Katharina Meyer
- Department of Design, University of Applied Science, 33619 Bielefeld, Germany; (P.S.); (K.M.)
| | - Holger Sudhoff
- Department of Otolaryngology, Head and Neck Surgery, Medical School OWL, Campus Bielefeld Mitte, Bielefeld University, 33604 Bielefeld, Germany; (W.R.); (H.S.); (I.T.)
| | - Ingo Todt
- Department of Otolaryngology, Head and Neck Surgery, Medical School OWL, Campus Bielefeld Mitte, Bielefeld University, 33604 Bielefeld, Germany; (W.R.); (H.S.); (I.T.)
| |
Collapse
|
3
|
Sandmeier T, Carreira EM. Enantioselective Synthesis of Cyclic Nitrones by Chemoselective Intramolecular Allylic Alkylation of Oximes. Angew Chem Int Ed Engl 2021; 60:9913-9918. [PMID: 33555650 DOI: 10.1002/anie.202100150] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/04/2021] [Indexed: 12/14/2022]
Abstract
The enantio- and chemoselective iridium-catalyzed N-allylation of oximes is described for the first time. Intramolecular kinetic resolution provides access to cyclic nitrones and enantioenriched aliphatic allylic alcohols. Salient features of this transformation are its ability to employ E/Z-isomeric mixtures of oxime starting materials convergently and high functional group tolerance. The implementation of N-allylation/1,3-dipolar cycloaddition reaction sequences furnishes tricyclic isoxazolidines in highly enantio- and diastereoselective fashion. The synthetic utility of the approach is demonstrated by the efficient, formal synthesis of the marine natural product (+)-halichlorine.
Collapse
Affiliation(s)
- Tobias Sandmeier
- Laboratorium für Organische Chemie, HCI H335, Eidgenössische Technische Hochschule Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| | - Erick M Carreira
- Laboratorium für Organische Chemie, HCI H335, Eidgenössische Technische Hochschule Zürich, Vladimir-Prelog-Weg 3, 8093, Zürich, Switzerland
| |
Collapse
|
4
|
Sandmeier T, Carreira EM. Enantioselective Synthesis of Cyclic Nitrones by Chemoselective Intramolecular Allylic Alkylation of Oximes. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202100150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Tobias Sandmeier
- Laboratorium für Organische Chemie HCI H335 Eidgenössische Technische Hochschule Zürich Vladimir-Prelog-Weg 3 8093 Zürich Switzerland
| | - Erick M. Carreira
- Laboratorium für Organische Chemie HCI H335 Eidgenössische Technische Hochschule Zürich Vladimir-Prelog-Weg 3 8093 Zürich Switzerland
| |
Collapse
|
5
|
Abstract
A method for the enantio- and chemoselective iridium-catalyzed O-allylation of oximes is described. Kinetic resolution in an intramolecular setting provides enantioenriched oxime ethers and aliphatic allylic alcohols. The synthetic potential of the products generated with this method is showcased by their elaboration into a series of heterocyclic compounds and the formal synthesis of glycoprotein GP IIb-IIIa receptor antagonist (-)-roxifiban. Preliminary mechanistic experiments and computational data shed light on the remarkable chemoselectivity of the reaction.
Collapse
Affiliation(s)
- Tobias Sandmeier
- Eidgenössische Technische Hochschule (ETH) Zürich, Building HCI, Vladimir-Prelog-Weg 3, 8093 Zürich, Switzerland
| | - Erick M Carreira
- Eidgenössische Technische Hochschule (ETH) Zürich, Building HCI, Vladimir-Prelog-Weg 3, 8093 Zürich, Switzerland
| |
Collapse
|
6
|
Sandmeier T, Sievertsen N, Carreira EM. Derailed
Ohira‐Bestmann
Reaction of
γ
,
δ
‐Unsaturated Aldehydes for the Stereoselective Synthesis of Cyclopenta[
c
]pyrazoles. Helv Chim Acta 2020. [DOI: 10.1002/hlca.202000058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Tobias Sandmeier
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied Biosciences ETH-Zürich CH-8093 Zürich Switzerland
| | - Niels Sievertsen
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied Biosciences ETH-Zürich CH-8093 Zürich Switzerland
| | - Erick M. Carreira
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied Biosciences ETH-Zürich CH-8093 Zürich Switzerland
| |
Collapse
|
7
|
Affiliation(s)
- Tobias Sandmeier
- ETH Zürich, Vladimir-Prelog-Weg 3, HCI, 8093 Zürich, Switzerland
| | | |
Collapse
|
8
|
Sandmeier T, Goetzke FW, Krautwald S, Carreira EM. Iridium-Catalyzed Enantioselective Allylic Substitution with Aqueous Solutions of Nucleophiles. J Am Chem Soc 2019; 141:12212-12218. [DOI: 10.1021/jacs.9b05830] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Tobias Sandmeier
- ETH Zürich, Vladimir-Prelog-Weg 3, HCI, 8093 Zürich, Switzerland
| | | | - Simon Krautwald
- ETH Zürich, Vladimir-Prelog-Weg 3, HCI, 8093 Zürich, Switzerland
| | | |
Collapse
|
9
|
Sandmeier T, Krautwald S, Carreira EM. Stereoselective Synthesis of Piperidines by Iridium-Catalyzed Cyclocondensation. Angew Chem Int Ed Engl 2017; 56:11515-11519. [DOI: 10.1002/anie.201706374] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Tobias Sandmeier
- Laboratorium für Organische Chemie, HCI H335; Eidgenössische Technische Hochschule Zürich; Vladimir-Prelog-Weg 3 8093 Zürich Switzerland
| | - Simon Krautwald
- Laboratorium für Organische Chemie, HCI H335; Eidgenössische Technische Hochschule Zürich; Vladimir-Prelog-Weg 3 8093 Zürich Switzerland
| | - Erick M. Carreira
- Laboratorium für Organische Chemie, HCI H335; Eidgenössische Technische Hochschule Zürich; Vladimir-Prelog-Weg 3 8093 Zürich Switzerland
| |
Collapse
|
10
|
Affiliation(s)
- Tobias Sandmeier
- Laboratorium für Organische Chemie, HCI H335; Eidgenössische Technische Hochschule Zürich; Vladimir-Prelog-Weg 3 8093 Zürich Switzerland
| | - Simon Krautwald
- Laboratorium für Organische Chemie, HCI H335; Eidgenössische Technische Hochschule Zürich; Vladimir-Prelog-Weg 3 8093 Zürich Switzerland
| | - Erick M. Carreira
- Laboratorium für Organische Chemie, HCI H335; Eidgenössische Technische Hochschule Zürich; Vladimir-Prelog-Weg 3 8093 Zürich Switzerland
| |
Collapse
|
11
|
Sandmeier T, Krautwald S, Zipfel HF, Carreira EM. Stereodivergent Dual Catalytic α‐Allylation of Protected α‐Amino‐ and α‐Hydroxyacetaldehydes. Angew Chem Int Ed Engl 2015; 54:14363-7. [DOI: 10.1002/anie.201506933] [Citation(s) in RCA: 176] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Tobias Sandmeier
- Laboratorium für Organische Chemie, HCI H335, Eidgenössische Technische Hochschule Zürich, Vladimir‐Prelog‐Weg 3, 8093 Zürich (Switzerland)
| | - Simon Krautwald
- Laboratorium für Organische Chemie, HCI H335, Eidgenössische Technische Hochschule Zürich, Vladimir‐Prelog‐Weg 3, 8093 Zürich (Switzerland)
| | - Hannes F. Zipfel
- Laboratorium für Organische Chemie, HCI H335, Eidgenössische Technische Hochschule Zürich, Vladimir‐Prelog‐Weg 3, 8093 Zürich (Switzerland)
| | - Erick M. Carreira
- Laboratorium für Organische Chemie, HCI H335, Eidgenössische Technische Hochschule Zürich, Vladimir‐Prelog‐Weg 3, 8093 Zürich (Switzerland)
| |
Collapse
|
12
|
Abstract
The first total synthesis of the marine polyketide (±)-hippolachnin A has been achieved in nine linear steps and an overall yield of 9%. Rapid access to the oxacyclobutapentalene core structure was secured by strategic application of an ene cyclization.
Collapse
Affiliation(s)
- Stefan A Ruider
- Laboratorium für Organische Chemie, ETH Zürich, HCI H335, Vladimir-Prelog-Weg 3, 8093 Zürich (Switzerland) http://www.carreira.ethz.ch
| | | | | |
Collapse
|
13
|
|