Reactivity of Planar-Chiral alpha-Ferrocenyl Carbocations towards Electron-Rich Aromatics

Marcus Korb, Julia Mahrholdt, Xianming Liu, Heinrich Lang

Research output: Contribution to journalArticle

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Abstract

The reaction of the enantiopure, planar-chiral alpha-ferrocenyl carbocation (S-p)-2-(P(=S)Ph-2)FcCH(2)(+) (Fc = Fe(eta(5)-C5H5)(eta(5)-C5H3)) towards electron-rich arenes C6H5E (E = NH2, NMe2, NiPr2, NPh2, PPh2, P(=S)Ph-2, OH, SH, SMe) regarding either a nucleophilic attack of the group E or an electrophilic aromatic substitution reaction of the arene at the CH2+ unit is reported. It was found that the amino, oxo or thio functionalities gave the respective ferrocenes in various product distributions, while the P-based species didn't. Appropriate thiophosphine derivatives could be reduced to their P-III species that were applied as supporting ligands in atropselective C,C cross-coupling reactions for the synthesis of sterically hindered biaryls, where sandwich compound (S-p)-1-(PPh2)-2-(o-NMe2-C6H4)CH2-Fc gave an ee of 69 % (1 mol-% [Pd]), which is up to date the highest observed value for planar-chiral ferrocenes. The absolute configuration of the chiral ferrocenes was confirmed by single-crystal X-ray diffraction analysis. For seleno phosphane 1-(P(=Se)Ph-2)-2-(CH2OH)-Fc a unique Se single-atom transfer occurred within its reaction with Sanger's reagent. The presence of two chemically different Se atoms in 1-(P(=Se)Ph-2)-2-(((2,4-(NO2)(2)-C6H3)Se)CH2)-Fc was confirmed by Se-77{H-1} NMR spectroscopy and single-crystal X-ray diffraction analysis, respectively.

Original languageEnglish
Pages (from-to)973-987
Number of pages15
JournalEuropean Journal of Inorganic Chemistry
Issue number7
DOIs
Publication statusPublished - 21 Feb 2019

Cite this

@article{3e59f76d81f74c808644a7ce432f9766,
title = "Reactivity of Planar-Chiral alpha-Ferrocenyl Carbocations towards Electron-Rich Aromatics",
abstract = "The reaction of the enantiopure, planar-chiral alpha-ferrocenyl carbocation (S-p)-2-(P(=S)Ph-2)FcCH(2)(+) (Fc = Fe(eta(5)-C5H5)(eta(5)-C5H3)) towards electron-rich arenes C6H5E (E = NH2, NMe2, NiPr2, NPh2, PPh2, P(=S)Ph-2, OH, SH, SMe) regarding either a nucleophilic attack of the group E or an electrophilic aromatic substitution reaction of the arene at the CH2+ unit is reported. It was found that the amino, oxo or thio functionalities gave the respective ferrocenes in various product distributions, while the P-based species didn't. Appropriate thiophosphine derivatives could be reduced to their P-III species that were applied as supporting ligands in atropselective C,C cross-coupling reactions for the synthesis of sterically hindered biaryls, where sandwich compound (S-p)-1-(PPh2)-2-(o-NMe2-C6H4)CH2-Fc gave an ee of 69 {\%} (1 mol-{\%} [Pd]), which is up to date the highest observed value for planar-chiral ferrocenes. The absolute configuration of the chiral ferrocenes was confirmed by single-crystal X-ray diffraction analysis. For seleno phosphane 1-(P(=Se)Ph-2)-2-(CH2OH)-Fc a unique Se single-atom transfer occurred within its reaction with Sanger's reagent. The presence of two chemically different Se atoms in 1-(P(=Se)Ph-2)-2-(((2,4-(NO2)(2)-C6H3)Se)CH2)-Fc was confirmed by Se-77{H-1} NMR spectroscopy and single-crystal X-ray diffraction analysis, respectively.",
keywords = "Ferrocene, Planar chirality, C,C Cross-coupling, Phosphine, Chiral biaryls, Selenium atom transfer, NUCLEAR-MAGNETIC-RESONANCE, ASYMMETRIC SUZUKI-MIYAURA, CARBON BOND FORMATION, C-13 NMR-SPECTRA, DIRECT CONVERSION, CONCISE SYNTHESIS, CHEMICAL-SHIFTS, METAL-COMPLEXES, LIGANDS, DERIVATIVES",
author = "Marcus Korb and Julia Mahrholdt and Xianming Liu and Heinrich Lang",
year = "2019",
month = "2",
day = "21",
doi = "10.1002/ejic.201801430",
language = "English",
pages = "973--987",
journal = "European Journal of Inorganic Chemistry",
issn = "1099-0682",
publisher = "Wiley-VCH Verlag GmbH & Co. KGaA",
number = "7",

}

Reactivity of Planar-Chiral alpha-Ferrocenyl Carbocations towards Electron-Rich Aromatics. / Korb, Marcus; Mahrholdt, Julia; Liu, Xianming; Lang, Heinrich.

In: European Journal of Inorganic Chemistry, No. 7, 21.02.2019, p. 973-987.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Reactivity of Planar-Chiral alpha-Ferrocenyl Carbocations towards Electron-Rich Aromatics

AU - Korb, Marcus

AU - Mahrholdt, Julia

AU - Liu, Xianming

AU - Lang, Heinrich

PY - 2019/2/21

Y1 - 2019/2/21

N2 - The reaction of the enantiopure, planar-chiral alpha-ferrocenyl carbocation (S-p)-2-(P(=S)Ph-2)FcCH(2)(+) (Fc = Fe(eta(5)-C5H5)(eta(5)-C5H3)) towards electron-rich arenes C6H5E (E = NH2, NMe2, NiPr2, NPh2, PPh2, P(=S)Ph-2, OH, SH, SMe) regarding either a nucleophilic attack of the group E or an electrophilic aromatic substitution reaction of the arene at the CH2+ unit is reported. It was found that the amino, oxo or thio functionalities gave the respective ferrocenes in various product distributions, while the P-based species didn't. Appropriate thiophosphine derivatives could be reduced to their P-III species that were applied as supporting ligands in atropselective C,C cross-coupling reactions for the synthesis of sterically hindered biaryls, where sandwich compound (S-p)-1-(PPh2)-2-(o-NMe2-C6H4)CH2-Fc gave an ee of 69 % (1 mol-% [Pd]), which is up to date the highest observed value for planar-chiral ferrocenes. The absolute configuration of the chiral ferrocenes was confirmed by single-crystal X-ray diffraction analysis. For seleno phosphane 1-(P(=Se)Ph-2)-2-(CH2OH)-Fc a unique Se single-atom transfer occurred within its reaction with Sanger's reagent. The presence of two chemically different Se atoms in 1-(P(=Se)Ph-2)-2-(((2,4-(NO2)(2)-C6H3)Se)CH2)-Fc was confirmed by Se-77{H-1} NMR spectroscopy and single-crystal X-ray diffraction analysis, respectively.

AB - The reaction of the enantiopure, planar-chiral alpha-ferrocenyl carbocation (S-p)-2-(P(=S)Ph-2)FcCH(2)(+) (Fc = Fe(eta(5)-C5H5)(eta(5)-C5H3)) towards electron-rich arenes C6H5E (E = NH2, NMe2, NiPr2, NPh2, PPh2, P(=S)Ph-2, OH, SH, SMe) regarding either a nucleophilic attack of the group E or an electrophilic aromatic substitution reaction of the arene at the CH2+ unit is reported. It was found that the amino, oxo or thio functionalities gave the respective ferrocenes in various product distributions, while the P-based species didn't. Appropriate thiophosphine derivatives could be reduced to their P-III species that were applied as supporting ligands in atropselective C,C cross-coupling reactions for the synthesis of sterically hindered biaryls, where sandwich compound (S-p)-1-(PPh2)-2-(o-NMe2-C6H4)CH2-Fc gave an ee of 69 % (1 mol-% [Pd]), which is up to date the highest observed value for planar-chiral ferrocenes. The absolute configuration of the chiral ferrocenes was confirmed by single-crystal X-ray diffraction analysis. For seleno phosphane 1-(P(=Se)Ph-2)-2-(CH2OH)-Fc a unique Se single-atom transfer occurred within its reaction with Sanger's reagent. The presence of two chemically different Se atoms in 1-(P(=Se)Ph-2)-2-(((2,4-(NO2)(2)-C6H3)Se)CH2)-Fc was confirmed by Se-77{H-1} NMR spectroscopy and single-crystal X-ray diffraction analysis, respectively.

KW - Ferrocene

KW - Planar chirality

KW - C,C Cross-coupling

KW - Phosphine

KW - Chiral biaryls

KW - Selenium atom transfer

KW - NUCLEAR-MAGNETIC-RESONANCE

KW - ASYMMETRIC SUZUKI-MIYAURA

KW - CARBON BOND FORMATION

KW - C-13 NMR-SPECTRA

KW - DIRECT CONVERSION

KW - CONCISE SYNTHESIS

KW - CHEMICAL-SHIFTS

KW - METAL-COMPLEXES

KW - LIGANDS

KW - DERIVATIVES

U2 - 10.1002/ejic.201801430

DO - 10.1002/ejic.201801430

M3 - Article

SP - 973

EP - 987

JO - European Journal of Inorganic Chemistry

JF - European Journal of Inorganic Chemistry

SN - 1099-0682

IS - 7

ER -