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Metal-free dehydropolymerisation of phosphine-boranes using cyclic (alkyl)(amino)carbenes as hydrogen acceptors

The divalent carbene carbon centre in cyclic (alkyl)(amino)carbenes (CAACs) is known to exhibit transition-metal-like insertion into E–H σ-bonds (E = H, N, Si, B, P, C, O) with formation of new, strong C–E and C–H bonds. Although subsequent transformations of the products represent an attractive str...

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Autores principales: Oldroyd, Nicola L., Chitnis, Saurabh S., Annibale, Vincent T., Arz, Marius I., Sparkes, Hazel A., Manners, Ian
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6435733/
https://www.ncbi.nlm.nih.gov/pubmed/30914640
http://dx.doi.org/10.1038/s41467-019-08967-8
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author Oldroyd, Nicola L.
Chitnis, Saurabh S.
Annibale, Vincent T.
Arz, Marius I.
Sparkes, Hazel A.
Manners, Ian
author_facet Oldroyd, Nicola L.
Chitnis, Saurabh S.
Annibale, Vincent T.
Arz, Marius I.
Sparkes, Hazel A.
Manners, Ian
author_sort Oldroyd, Nicola L.
collection PubMed
description The divalent carbene carbon centre in cyclic (alkyl)(amino)carbenes (CAACs) is known to exhibit transition-metal-like insertion into E–H σ-bonds (E = H, N, Si, B, P, C, O) with formation of new, strong C–E and C–H bonds. Although subsequent transformations of the products represent an attractive strategy for metal-free synthesis, few examples have been reported. Herein we describe the dehydrogenation of phosphine-boranes, RR’PH·BH(3), using a CAAC, which behaves as a stoichiometric hydrogen acceptor to release monomeric phosphinoboranes, [RR’PBH(2)], under mild conditions. The latter species are transient intermediates that either polymerise to the corresponding polyphosphinoboranes, [RR’PBH(2)](n) (R = Ph; R’ = H, Ph or Et), or are trapped in the form of CAAC-phosphinoborane adducts, CAAC·H(2)BPRR’ (R = R’ = tBu; R = R’ = Mes). In contrast to previously established methods such as transition metal-catalysed dehydrocoupling, which only yield P-monosubstituted polymers, [RHPBH(2)](n), the CAAC-mediated route also provides access to P-disubstituted polymers, [RR’PBH(2)](n) (R = Ph; R’ = Ph or Et).
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spelling pubmed-64357332019-03-28 Metal-free dehydropolymerisation of phosphine-boranes using cyclic (alkyl)(amino)carbenes as hydrogen acceptors Oldroyd, Nicola L. Chitnis, Saurabh S. Annibale, Vincent T. Arz, Marius I. Sparkes, Hazel A. Manners, Ian Nat Commun Article The divalent carbene carbon centre in cyclic (alkyl)(amino)carbenes (CAACs) is known to exhibit transition-metal-like insertion into E–H σ-bonds (E = H, N, Si, B, P, C, O) with formation of new, strong C–E and C–H bonds. Although subsequent transformations of the products represent an attractive strategy for metal-free synthesis, few examples have been reported. Herein we describe the dehydrogenation of phosphine-boranes, RR’PH·BH(3), using a CAAC, which behaves as a stoichiometric hydrogen acceptor to release monomeric phosphinoboranes, [RR’PBH(2)], under mild conditions. The latter species are transient intermediates that either polymerise to the corresponding polyphosphinoboranes, [RR’PBH(2)](n) (R = Ph; R’ = H, Ph or Et), or are trapped in the form of CAAC-phosphinoborane adducts, CAAC·H(2)BPRR’ (R = R’ = tBu; R = R’ = Mes). In contrast to previously established methods such as transition metal-catalysed dehydrocoupling, which only yield P-monosubstituted polymers, [RHPBH(2)](n), the CAAC-mediated route also provides access to P-disubstituted polymers, [RR’PBH(2)](n) (R = Ph; R’ = Ph or Et). Nature Publishing Group UK 2019-03-26 /pmc/articles/PMC6435733/ /pubmed/30914640 http://dx.doi.org/10.1038/s41467-019-08967-8 Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Oldroyd, Nicola L.
Chitnis, Saurabh S.
Annibale, Vincent T.
Arz, Marius I.
Sparkes, Hazel A.
Manners, Ian
Metal-free dehydropolymerisation of phosphine-boranes using cyclic (alkyl)(amino)carbenes as hydrogen acceptors
title Metal-free dehydropolymerisation of phosphine-boranes using cyclic (alkyl)(amino)carbenes as hydrogen acceptors
title_full Metal-free dehydropolymerisation of phosphine-boranes using cyclic (alkyl)(amino)carbenes as hydrogen acceptors
title_fullStr Metal-free dehydropolymerisation of phosphine-boranes using cyclic (alkyl)(amino)carbenes as hydrogen acceptors
title_full_unstemmed Metal-free dehydropolymerisation of phosphine-boranes using cyclic (alkyl)(amino)carbenes as hydrogen acceptors
title_short Metal-free dehydropolymerisation of phosphine-boranes using cyclic (alkyl)(amino)carbenes as hydrogen acceptors
title_sort metal-free dehydropolymerisation of phosphine-boranes using cyclic (alkyl)(amino)carbenes as hydrogen acceptors
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6435733/
https://www.ncbi.nlm.nih.gov/pubmed/30914640
http://dx.doi.org/10.1038/s41467-019-08967-8
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