Abstract
(Ferrocenylthienyl)phosphines of type 2-PR2-5-Fc-(C4H2S)-C-c (R = Ph (3a), Bu-t (3b)) and 2-PR2-3,4-Fc(2)-(C4HS)-C-c (R = Ph (4a), Bu-t (4b); Fc = Fe(eta(5)-C5H4)(eta(5)-C5H5)) and their selenium derivatives were synthesized by consecutive synthetic methodologies. The molecular structure of 3a and 4a, b in the solid state show inter-and intramolecular (T-shaped) pep interactions for 3a and 4a, resulting in dimeric and 1D polymeric structures.
Phosphines 3a, b and 4a, b were applied in the Pd-catalyzed Suzuki-Miyaura C,C cross coupling reaction of aryl halides and boronic acids yielding the respective biaryls. Compound 3b shows a higher activity in C, C cross coupling reactions as compared to 3a and previously published thiophene-based phosphines and aminophosphines. Moreover sterically hindered and deactivated aryl bromides could be coupled at Pd loadings as low as 0.05 mol-% and at temperatures between 25 degrees C and 50 degrees C. However, the application of diferrocenylthienylphosphines 4a, b in Suzuki-Miyaura reactions resulted in decreased yields of the corresponding biaryls.
In the context of electrochemical investigations on these compounds, a strong dependency of the individual electrode reactions on the phosphorus substituents were found. During UV-Vis/NIR spectroelectrochemical studies, only a very limited iron-iron electronic interaction in 4a-Se+ could be detected. Thus, 4a-Se+ corresponds to a very weak coupled class II system according to the classification of Robin and Day. (C) 2016 Elsevier B.V. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 26-35 |
| Number of pages | 10 |
| Journal | Journal of Organometallic Chemistry |
| Volume | 813 |
| DOIs | |
| Publication status | Published - 1 Jul 2016 |
| Externally published | Yes |
Cite this
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(Ferrocenylthienyl) phosphines : Synthesis, electrochemistry and their use in Suzuki-Miyaura C, C coupling. / Gaebler, Christian; Speck, J. Matthaeus; Korb, Marcus; Schaarschmidt, Dieter; Lang, Heinrich.
In: Journal of Organometallic Chemistry, Vol. 813, 01.07.2016, p. 26-35.Research output: Contribution to journal › Article
TY - JOUR
T1 - (Ferrocenylthienyl) phosphines
T2 - Synthesis, electrochemistry and their use in Suzuki-Miyaura C, C coupling
AU - Gaebler, Christian
AU - Speck, J. Matthaeus
AU - Korb, Marcus
AU - Schaarschmidt, Dieter
AU - Lang, Heinrich
PY - 2016/7/1
Y1 - 2016/7/1
N2 - (Ferrocenylthienyl)phosphines of type 2-PR2-5-Fc-(C4H2S)-C-c (R = Ph (3a), Bu-t (3b)) and 2-PR2-3,4-Fc(2)-(C4HS)-C-c (R = Ph (4a), Bu-t (4b); Fc = Fe(eta(5)-C5H4)(eta(5)-C5H5)) and their selenium derivatives were synthesized by consecutive synthetic methodologies. The molecular structure of 3a and 4a, b in the solid state show inter-and intramolecular (T-shaped) pep interactions for 3a and 4a, resulting in dimeric and 1D polymeric structures.Phosphines 3a, b and 4a, b were applied in the Pd-catalyzed Suzuki-Miyaura C,C cross coupling reaction of aryl halides and boronic acids yielding the respective biaryls. Compound 3b shows a higher activity in C, C cross coupling reactions as compared to 3a and previously published thiophene-based phosphines and aminophosphines. Moreover sterically hindered and deactivated aryl bromides could be coupled at Pd loadings as low as 0.05 mol-% and at temperatures between 25 degrees C and 50 degrees C. However, the application of diferrocenylthienylphosphines 4a, b in Suzuki-Miyaura reactions resulted in decreased yields of the corresponding biaryls.In the context of electrochemical investigations on these compounds, a strong dependency of the individual electrode reactions on the phosphorus substituents were found. During UV-Vis/NIR spectroelectrochemical studies, only a very limited iron-iron electronic interaction in 4a-Se+ could be detected. Thus, 4a-Se+ corresponds to a very weak coupled class II system according to the classification of Robin and Day. (C) 2016 Elsevier B.V. All rights reserved.
AB - (Ferrocenylthienyl)phosphines of type 2-PR2-5-Fc-(C4H2S)-C-c (R = Ph (3a), Bu-t (3b)) and 2-PR2-3,4-Fc(2)-(C4HS)-C-c (R = Ph (4a), Bu-t (4b); Fc = Fe(eta(5)-C5H4)(eta(5)-C5H5)) and their selenium derivatives were synthesized by consecutive synthetic methodologies. The molecular structure of 3a and 4a, b in the solid state show inter-and intramolecular (T-shaped) pep interactions for 3a and 4a, resulting in dimeric and 1D polymeric structures.Phosphines 3a, b and 4a, b were applied in the Pd-catalyzed Suzuki-Miyaura C,C cross coupling reaction of aryl halides and boronic acids yielding the respective biaryls. Compound 3b shows a higher activity in C, C cross coupling reactions as compared to 3a and previously published thiophene-based phosphines and aminophosphines. Moreover sterically hindered and deactivated aryl bromides could be coupled at Pd loadings as low as 0.05 mol-% and at temperatures between 25 degrees C and 50 degrees C. However, the application of diferrocenylthienylphosphines 4a, b in Suzuki-Miyaura reactions resulted in decreased yields of the corresponding biaryls.In the context of electrochemical investigations on these compounds, a strong dependency of the individual electrode reactions on the phosphorus substituents were found. During UV-Vis/NIR spectroelectrochemical studies, only a very limited iron-iron electronic interaction in 4a-Se+ could be detected. Thus, 4a-Se+ corresponds to a very weak coupled class II system according to the classification of Robin and Day. (C) 2016 Elsevier B.V. All rights reserved.
KW - Suzuki-Miyaura C,C cross-coupling
KW - Ferrocene
KW - Phosphine
KW - Solid state structure
KW - Electrochemistry
KW - NUCLEAR-MAGNETIC-RESONANCE
KW - MIXED-VALENCE COMPOUNDS
KW - CYCLIC VOLTAMMETRY
KW - ELECTRON-TRANSFER
KW - REDOX PROPERTIES
KW - HETEROARYLPHOSPHORUS COMPOUNDS
KW - ORGANOPHOSPHORUS COMPOUNDS
KW - 5-MEMBERED HETEROCYCLES
KW - DELTA-E-1/2 VALUES
KW - FERROCENE LIGANDS
U2 - 10.1016/j.jorganchem.2016.03.027
DO - 10.1016/j.jorganchem.2016.03.027
M3 - Article
VL - 813
SP - 26
EP - 35
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
SN - 0022-328X
ER -