New Halo Compounds of Si, P, As, AND Sb Bearing a Bulky Substituted Fluorenyl Group

Baiget, Lise; Bouslikhane, Mereyim; Escudié, J.; Nemeş, Gabriela; Silaghi‐Dumitrescu, Ioan; Silaghi‐Dumitrescu, Luminiţa

doi:10.1080/10426500390228639

Cited by 19 publications

(13 citation statements)

References 20 publications

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“…[70,71] Simple (no additional substituents) 9-substituted fluorenylphosphines are prepared (Scheme 1) by reactions of the deprotonated fluorene (nBuLi) with various alkyl halides (MeI, EtI, iPrI, PhCH 2 Cl, C 18 H 37 Br) to selectively introduce alkyl groups into the 9-position in virtually quantitative yield. This first alkylation step is essential as our very first catalysis screens had revealed that phosphines with 9-R = H produce Pd-complex catalysts with modest activities in cross-coupling reactions.…”

Section: Resultsmentioning

confidence: 99%

9‐Fluorenylphosphines for the Pd‐Catalyzed Sonogashira, Suzuki, and Buchwald–Hartwig Coupling Reactions in Organic Solvents and Water

Fleckenstein

Plenio

2007

Chemistry A European J

173

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The lithiation/alkylation of fluorene leads to various 9-alkyl-fluorenes (alkyl=Me, Et, iPr, -Pr, -C18H25) in>95% yields, for which lithiation and reaction with R2PCl (R=Cy, iPr, tBu) generates 9-alkyl, 9-PR2-fluorenes which constitute electron-rich and bulky phosphine ligands. The in-situ-formed palladium-phosphine complexes ([Na2PdCl4], phosphonium salt, base, substrates) were tested in the Sonogashira, Suzuki, and Buchwald-Hartwig reactions of aryl chlorides and aryl bromides in organic solvents. The Sonogashira coupling of aryl chlorides at 100-120 degrees C leads to>90% yields with 1 mol% of Pd catalyst. The Suzuki coupling of aryl chlorides typically requires 0.05 mol% of Pd catalyst at 100 degrees C in dioxane for quantitative product formation. To carry out "green" cross-coupling reactions in water, 9-ethylfluorenyldicyclohexylphosphine was reacted in sulphuric acid to generate the respective 2-sulfonated phosphonium salt. The Suzuki coupling of activated aryl chlorides by using this water-soluble catalyst requires only 0.01 mol% of Pd catalyst, while a wide range of aryl chlorides can be quantitatively converted into the respective coupling products by using 0.1-0.5 mol% of catalyst in pure water at 100 degrees C. Difficult substrate combinations, such as naphthylboronic acid or 3-pyridylboronic acid and aryl chlorides are coupled at 100 degrees C by using 0.1-0.5 mol% of catalyst in pure water to obtain the respective N-heterocycles in quantitative yields. The copper-free aqueous Sonogashira coupling of aryl bromides generates the respective tolane derivatives in>95% yield.

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Section: Resultsmentioning

confidence: 99%

9‐Fluorenylphosphines for the Pd‐Catalyzed Sonogashira, Suzuki, and Buchwald–Hartwig Coupling Reactions in Organic Solvents and Water

Fleckenstein

Plenio

2007

Chemistry A European J

173

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“…The starting point of the synthesis of MePh 2 P(flu) (see scheme 1) is the phosphine Ph 2 P (fluH) (1) (fluH = fluorenyl; see figure 1), which can be conveniently prepared by reaction of in situ generated lithium fluorenide and chlorodiphenylphosphine, as reported by Escudie and co-workers [7]. Subsequent quaternization of 1 was achieved by reaction with iodomethane in toluene, leading to the colorless phosphonium iodide [MePh 2 P(fluH)]I (2) in excellent yield.…”

Section: Synthesis Of the Phosphonium Ylide And Its Precursorsmentioning

confidence: 99%

An unsymmetrical phosphonium diylide with a fluorenylidene subunit and its lithium complexes

Geitner

Kosygin

Görls

et al. 2015

Journal of Coordination Chemistry

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The phosphonium ylide MePh 2 P(flu) (3) (flu = C 13 H 8 , fluorenylidene) was conveniently prepared by reaction of Ph 2 P(fluH) (1) (fluH = C 13 H 9 , fluorenyl) with iodomethane, followed by subsequent dehydrohalogenation of the resulting phosphonium salt [MePh 2 P(fluH)]I (2) by potassium tert-butoxide. Compound 3 was further deprotonated by n-butyllithium, yielding the corresponding lithium complex [Li{CH 2 PPh 2 (flu)}(tmeda)] (4) in presence of N,N,N′,N′-tetramethylethylenediamine (tmeda). This mononuclear lithium compound contains the monoanionic chelating diylidic ligand. An exchange of the neutral bidentate tmeda by tridentate N,N,N′,N′′,N′′-pentamethyldiethylenetriamine (pmdta) enforces a change in coordination mode. Consequently, the diylide is monodentate in [Li{CH 2 PPh 2 (flu)}(pmdta)] (5). Compounds 1-5 were characterized by NMR spectroscopy and single-crystal X-ray diffraction experiments.

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“…[22,23] 13 C NMR spectrum of compound 2 appears at 137.3 as a doublet ( 1 J C-P = 104.3 Hz), because of the bonding with the phosphorus atom, with a downfield shift from 124.6 ppm for bis-sulfone 1, characteristic shift and coupling constant for such derivatives. [22,24] The structure of the bis-sulfone-dichlorophosphine 2 was confirmed in solid state by single crystal X-ray diffraction; the molecular structure together with some important geometrical parameters is presented in Figure 1. The solid state molecular structure of compound 2 shows that the phosphorus atom adopts a pseudo-tetrahedral geometry, considering the lone pair of electrons, with the angles C1-P1-Cl1 of 104.37(11)°, C1-P1-Cl2 of 99.57(11)° and Cl1-P1-Cl2 of 102.80(6)°.…”

Section: Scheme 1 Synthesis Of Phosphorus Containing Derivativesmentioning

confidence: 97%

New phosphorus containing bis-sulfone ligands

Deak¹,

Mallet‐Ladeira²,

Silaghi‐Dumitrescu³

et al. 2017

Studia UBB Chemia

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ABSTRACT.Derivatives of bis-sulfone 1,3-bis{(p-tolyl)SO2}-5-tertbutylbenzene 1, containing P(III) and P(V) were obtained and characterized in solution by multinuclear NMR spectroscopy. For two of the compounds ([2,6-{(p-tolyl)SO2}24-t-Bu-C6H2]PCl2 2 and [2,6-{(p-tolyl)SO2}24-t-Bu-C6H2]P(O)(H)OEt) 4 the crystal and molecular structures in solid state were also determined by single crystal X-ray diffraction.

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New Halo Compounds of Si, P, As, AND Sb Bearing a Bulky Substituted Fluorenyl Group

Cited by 19 publications

References 20 publications

9‐Fluorenylphosphines for the Pd‐Catalyzed Sonogashira, Suzuki, and Buchwald–Hartwig Coupling Reactions in Organic Solvents and Water

9‐Fluorenylphosphines for the Pd‐Catalyzed Sonogashira, Suzuki, and Buchwald–Hartwig Coupling Reactions in Organic Solvents and Water

An unsymmetrical phosphonium diylide with a fluorenylidene subunit and its lithium complexes

New phosphorus containing bis-sulfone ligands

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