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Ti(III) Catalysts for CO(2)/Epoxide Copolymerization at Unusual Ambient Pressure Conditions
[Image: see text] Titanium compounds in low oxidation states are highly reducing species and hence powerful tools for the functionalization of small molecules. However, their potential has not yet been fully realized because harnessing these highly reactive complexes for productive reactivity is gen...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2023
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10521022/ https://www.ncbi.nlm.nih.gov/pubmed/37651747 http://dx.doi.org/10.1021/acs.inorgchem.3c01249 |
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author | Sancho, Ignacio Navarro, Marta Montilla, Marc Salvador, Pedro Santamaría, Cristina Luis, Josep M. Hernán-Gómez, Alberto |
author_facet | Sancho, Ignacio Navarro, Marta Montilla, Marc Salvador, Pedro Santamaría, Cristina Luis, Josep M. Hernán-Gómez, Alberto |
author_sort | Sancho, Ignacio |
collection | PubMed |
description | [Image: see text] Titanium compounds in low oxidation states are highly reducing species and hence powerful tools for the functionalization of small molecules. However, their potential has not yet been fully realized because harnessing these highly reactive complexes for productive reactivity is generally challenging. Advancing this field, herein we provide a detailed route for the formation of titanium(III) orthophenylendiamido (PDA) species using [LiBHEt(3)] as a reducing agent. Initially, the corresponding lithium PDA compounds [Li(2)((Ar)PDA)(thf)(3)] (Ar = 2,4,6-trimethylphenyl ((Mes)PDA), 2,6-diisopropylphenyl ((iPr)PDA)) are combined with [TiCl(4)(thf)(2)] to form the heterobimetallic complexes [{TiCl((Ar)PDA)}(μ-(Ar)PDA){Li(thf)(n)}] (n = 1, Ar = iPr 3 and n = 2, Ar = Mes 4). Compound 4 evolves to species [Ti((Mes)PDA)(2)] (6) via thermal treatment. In contrast, the transformation of 3 into [Ti((iPr)PDA)(2)] (5) only occurs in the presence of [LiNMe(2)], through a lithium-assisted process, as revealed by density functional theory (DFT). Finally, the Ti(IV) compounds 3–6 react with [LiBHEt(3)] to give rise to the Ti(III) species [Li(thf)(4)][Ti((Ar)PDA)(2)] (Ar = iPr 8, Mes 9). These low-valent compounds in combination with [PPN]Cl (PPN = bis(triphenylphosphine)iminium) are proved to be highly selective catalysts for the copolymerization of CO(2) and cyclohexene epoxide. Reactions occur at 1 bar pressure with activity/selectivity levels similar to Salen–Cr(III) compounds. |
format | Online Article Text |
id | pubmed-10521022 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-105210222023-09-27 Ti(III) Catalysts for CO(2)/Epoxide Copolymerization at Unusual Ambient Pressure Conditions Sancho, Ignacio Navarro, Marta Montilla, Marc Salvador, Pedro Santamaría, Cristina Luis, Josep M. Hernán-Gómez, Alberto Inorg Chem [Image: see text] Titanium compounds in low oxidation states are highly reducing species and hence powerful tools for the functionalization of small molecules. However, their potential has not yet been fully realized because harnessing these highly reactive complexes for productive reactivity is generally challenging. Advancing this field, herein we provide a detailed route for the formation of titanium(III) orthophenylendiamido (PDA) species using [LiBHEt(3)] as a reducing agent. Initially, the corresponding lithium PDA compounds [Li(2)((Ar)PDA)(thf)(3)] (Ar = 2,4,6-trimethylphenyl ((Mes)PDA), 2,6-diisopropylphenyl ((iPr)PDA)) are combined with [TiCl(4)(thf)(2)] to form the heterobimetallic complexes [{TiCl((Ar)PDA)}(μ-(Ar)PDA){Li(thf)(n)}] (n = 1, Ar = iPr 3 and n = 2, Ar = Mes 4). Compound 4 evolves to species [Ti((Mes)PDA)(2)] (6) via thermal treatment. In contrast, the transformation of 3 into [Ti((iPr)PDA)(2)] (5) only occurs in the presence of [LiNMe(2)], through a lithium-assisted process, as revealed by density functional theory (DFT). Finally, the Ti(IV) compounds 3–6 react with [LiBHEt(3)] to give rise to the Ti(III) species [Li(thf)(4)][Ti((Ar)PDA)(2)] (Ar = iPr 8, Mes 9). These low-valent compounds in combination with [PPN]Cl (PPN = bis(triphenylphosphine)iminium) are proved to be highly selective catalysts for the copolymerization of CO(2) and cyclohexene epoxide. Reactions occur at 1 bar pressure with activity/selectivity levels similar to Salen–Cr(III) compounds. American Chemical Society 2023-08-31 /pmc/articles/PMC10521022/ /pubmed/37651747 http://dx.doi.org/10.1021/acs.inorgchem.3c01249 Text en © 2023 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Sancho, Ignacio Navarro, Marta Montilla, Marc Salvador, Pedro Santamaría, Cristina Luis, Josep M. Hernán-Gómez, Alberto Ti(III) Catalysts for CO(2)/Epoxide Copolymerization at Unusual Ambient Pressure Conditions |
title | Ti(III) Catalysts
for CO(2)/Epoxide Copolymerization
at Unusual Ambient Pressure Conditions |
title_full | Ti(III) Catalysts
for CO(2)/Epoxide Copolymerization
at Unusual Ambient Pressure Conditions |
title_fullStr | Ti(III) Catalysts
for CO(2)/Epoxide Copolymerization
at Unusual Ambient Pressure Conditions |
title_full_unstemmed | Ti(III) Catalysts
for CO(2)/Epoxide Copolymerization
at Unusual Ambient Pressure Conditions |
title_short | Ti(III) Catalysts
for CO(2)/Epoxide Copolymerization
at Unusual Ambient Pressure Conditions |
title_sort | ti(iii) catalysts
for co(2)/epoxide copolymerization
at unusual ambient pressure conditions |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10521022/ https://www.ncbi.nlm.nih.gov/pubmed/37651747 http://dx.doi.org/10.1021/acs.inorgchem.3c01249 |
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