Reactions of phosphorus compounds. Part XXIII. Preparation and reactions of several α-substituted vinylphosphonium salts

Schweizer, Edward E.; Wehman, Anthony T.

doi:10.1039/j39710000343

Cited by 6 publications

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“…The first step involved the hydrobromination of styrene (18) by a literature procedure [13] to give (1-bromoethyl)benzene (19) in 88-99 % yield after distillation in vacuo. Subsequent conversion to compound 20, involving procedures described in the literature, [14,15] resulted in yields lower than 50 %, which prompted us to optimize the reaction conditions (Table 1). Benzyltriphenylphosphonium bromide 20 was finally obtained in 88 % yield by heating 19 at reflux with triphenylphosphane in toluene for 3 days in a screw-capped flask.…”

Section: Resultsmentioning

confidence: 99%

“…[14] [b] Yield of 78 % according to the literature. [15] Diformylcalixarene 3 [16] was then transformed into the corresponding distyrylcalixarene 21 in 42 % yield under Wittig conditions (Scheme 7). Its 1 H NMR spectrum is much less complicated than that of the corresponding distyrylcalixarene 4 without the additional methyl groups on the styryl moiety as compound 21 seems to be formed almost exclusively as the E,E isomer.…”

Section: Resultsmentioning

confidence: 99%

“…The NMR spectroscopic data are in accord with the literature. [14,15] cone-5,17-Bis(2-methyl-2-phenylethenyl)-25,26,27,28-tetra-n-propoxycalix [4]arene (21): nBuLi (1.5 mL, 15 % in hexane, 2.39 mmol) was added to a cooled (-78°C) suspension of phosphonium bromide 20 (854 mg, 1.92 mmol) in dry THF (20 mL). The reaction mixture was stirred for 45 min at -78°C and for 30 min at room temperature.…”

Section: Cone-(ez)-517-bis[2-phenylethenyl]-25262728-tetra-n-promentioning

confidence: 99%

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Multifold Photocyclization Reactions of Styrylcalix[4]arenes

et al. 2010

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Cone-(ez)-517-bis[2-phenylethenyl]-25262728-tetra-n-promentioning

confidence: 99%

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Multifold Photocyclization Reactions of Styrylcalix[4]arenes

et al. 2010

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“…9). Unfortunately, 15 was contaminated with varying amounts of another product which we presume to be 16 derived by [9] …”

Section: 'mentioning

confidence: 99%

“…2), a type of reaction well known to afford very low yields of phosphonium salts (see ref. 9 for a list of references). However, this route offers the possibility of complete generality if the alkylated salts 4 could be prepared more efficiently.…”

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Some methods for the preparation of α-alkylated vinylphosphonium salts and their use in 2,5-dihydrothiophene synthesis

McIntosh¹,

Steevensz²

1977

Can. J. Chem.

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The preparation of a series of vinyltriphenylphosphonium salts, all of which bear a substituent on the carbon attached to phosphorus, is described. Yields are generally poor unless a symmetrical secondary allylic halide can be used. The use of these salts in the preparation of substituted 2,5-dihydrothiophenes has been examined. In general, reaction times are increased and product yields decreased relative to the reactions of the unsubstituted salts previously reported. This result is ascribed to steric inhibition of the intramolecular Wittig reaction.

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Voltammetric Characterization of Redox‐Inactive Guest Binding to Ln^III[15‐Metallacrown‐5] Hosts Based on Competition with a Redox Probe

Jankolovits

Kampf

Maldonado

et al. 2010

Chemistry A European J

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A novel competitive binding assay was implemented to monitor the binding of a redox inactive substrate to a redox inactive metallacrown host based on its competition with ferrocene carboxylate (FcC(-)) using cyclic voltammetry (CV). First, the binding of FcC(-) to Ln(III)[15-MC(Cu(II),N,L-pheHA)-5] (LnMC) hosts was characterized by cyclic voltammetry. It was shown that the voltammetric half wave potentials, E(1/2), shifted to more positive potentials upon the addition of LnMC. The explicit dependence of E(1/2) with the concentration of LnMC was used to determine the association constants for the complex. The FcC(-) binding strength decreased with larger central lanthanide metals in the LnMC hosts, and substantially weaker binding was observed with La(III). X-ray crystallography revealed that the hydrophobic host cavity incompletely encapsulated FcC(-) when the guest was bound to the nine-coordinate La(III), suggesting the LnMC's ligand side chains play a substantial role in guest recognition. With knowledge of the MC-FcC(-) solution thermodynamics, the binding affinity of a redox inactive guest was then assessed. Addition of sodium benzoate to a LnMC and FcC(-) mixture resulted in E(1/2) shifting back to the value observed for FcC(-) in the absence of LnMC. The association constants between benzoate and LnMC's were calculated via the competitive binding approach. Comparison with literature values suggests this novel assay is a viable method for determining association constants for host-guest systems that exhibit the proper electrochemical behavior. Notably, this CV competitive binding approach does not require the preparation of a modified electrode or a tethered guest, and thus can be generalized to a number of host-guest systems.

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Reactions of phosphorus compounds. Part XXIII. Preparation and reactions of several α-substituted vinylphosphonium salts

Cited by 6 publications

References 0 publications

Multifold Photocyclization Reactions of Styrylcalix[4]arenes

Multifold Photocyclization Reactions of Styrylcalix[4]arenes

Some methods for the preparation of α-alkylated vinylphosphonium salts and their use in 2,5-dihydrothiophene synthesis

Voltammetric Characterization of Redox‐Inactive Guest Binding to Ln^III[15‐Metallacrown‐5] Hosts Based on Competition with a Redox Probe

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Reactions of phosphorus compounds. Part XXIII. Preparation and reactions of several α-substituted vinylphosphonium salts

Cited by 6 publications

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Multifold Photocyclization Reactions of Styrylcalix[4]arenes

Multifold Photocyclization Reactions of Styrylcalix[4]arenes

Some methods for the preparation of α-alkylated vinylphosphonium salts and their use in 2,5-dihydrothiophene synthesis

Voltammetric Characterization of Redox‐Inactive Guest Binding to LnIII[15‐Metallacrown‐5] Hosts Based on Competition with a Redox Probe

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Voltammetric Characterization of Redox‐Inactive Guest Binding to Ln^III[15‐Metallacrown‐5] Hosts Based on Competition with a Redox Probe