Synthesis and structure of annulated dithieno[2,3-b;3′,2′-d]thienyl- and ring-opened 3,3′-bithienyl Fischer carbene complexes |
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Author: | Lamprecht, Zandria1; Malan, Frederick P.1; Liles, David C.1; |
Organizations: |
1Department of Chemistry, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa 2Laboratory of Inorganic Chemistry, Environmental and Chemical Engineering, University of Oulu, P. O. Box 3000, 90014, Oulu, Finland |
Format: | article |
Version: | published version |
Access: | open |
Online Access: | PDF Full Text (PDF, 1.8 MB) |
Persistent link: | http://urn.fi/urn:nbn:fi-fe2020090768759 |
Language: | English |
Published: |
Elsevier,
2020
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Publish Date: | 2020-09-07 |
Description: |
AbstractNucleophilic attack on the central sulphur of dithieno[2,3-b;3′,2′-d]thiophene (DTT) by n-BuLi opens the central thiophene ring and afforded, after subsequent reaction with Cr(CO)₆ and alkylation with [Et₃O][BF₄], a series of mono- and biscarbene complexes containing a 3,3′-dithienyl backbone with a SBu substituent. Repeating the reaction with diisopropylamine as the nucleophile, leads to a dihydrodesulphurization reaction with ring-opening of the central thiophene ring of DTT and elimination of the sulphur atom. Subsequent reaction with n-BuLi or LDA, Cr(CO)₆ and [Et₃O][BF₄] afforded 3,3′-dithienyl mono- and biscarbene complexes. In both instances α,α′-dithienothiophene biscarbene complex was observed spectroscopically but not isolated. By using α,α′-dibromodithieno[2,3-b;3′,2′]thiophene as substrate, improved yields of the targeted mono- and biscarbene complexes of [2,3-b;3′,2′-d]-DTT (M=Cr, W) could be obtained. The biscarbene complexes were unstable in the reaction mixture but in the case of tungsten could be isolated after in situ aminolysis with dimethylamine. The use of KHMDS as base converted Cr(CO)₆ to K[Cr(CO)₅(CN)] and after reaction with DTT and subsequent alkylation with [Et₃O][BF₄], afforded the chromium tetracarbonyl carbene complex of DTT. see all
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Series: |
Journal of organometallic chemistry |
ISSN: | 0022-328X |
ISSN-E: | 1872-8561 |
ISSN-L: | 0022-328X |
Volume: | 925 |
Article number: | 121466 |
DOI: | 10.1016/j.jorganchem.2020.121466 |
OADOI: | https://oadoi.org/10.1016/j.jorganchem.2020.121466 |
Type of Publication: |
A1 Journal article – refereed |
Field of Science: |
116 Chemical sciences 215 Chemical engineering |
Subjects: | |
Funding: |
The authors gratefully acknowledge the National Research Foundation, South Africa (NRF 105740; NRF 105529 NRF 87788 and NRF 9772) and Sasol Technology R&D Pty. Ltd. (South Africa) for financial support. |
Copyright information: |
© 2020 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license. ( http://creativecommons.org/licenses/by/4.0/ ) |
https://creativecommons.org/licenses/by/4.0/ |