A study of periselectivity in the thermal cyclisation reactions of diene-conjugated diazo compounds: 1,7-cyclisation as a route to 3H-1,2-diazepines and 1,5-cyclisation leading to new rearrangement reactions of 3H-pyrazoles

Robertson, Ian R.; Sharp, John T.

doi:10.1016/s0040-4020(01)82434-0

Cited by 45 publications

(14 citation statements)

References 25 publications

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“…MS (FAB): m / z (%) = 367 (100) [M] + . The NMR spectroscopic data are in accord with the literature 14,15…”

Section: Methodssupporting

confidence: 77%

“…The first step involved the hydrobromination of styrene ( 18 ) by a literature procedure13 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%

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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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“…MS (FAB): m / z (%) = 367 (100) [M] + . The NMR spectroscopic data are in accord with the literature 14,15…”

Section: Methodssupporting

confidence: 77%

Section: Resultsmentioning

confidence: 99%

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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“…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%

“…[a] Yield of 80 % according to the literature. [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).…”

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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Tetrahydropentalene

Pauli

Meier

1987

Chem. Ber.

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A study of periselectivity in the thermal cyclisation reactions of diene-conjugated diazo compounds: 1,7-cyclisation as a route to 3H-1,2-diazepines and 1,5-cyclisation leading to new rearrangement reactions of 3H-pyrazoles

Cited by 45 publications

References 25 publications

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

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

Multifold Photocyclization Reactions of Styrylcalix[4]arenes

Tetrahydropentalene

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A study of periselectivity in the thermal cyclisation reactions of diene-conjugated diazo compounds: 1,7-cyclisation as a route to 3H-1,2-diazepines and 1,5-cyclisation leading to new rearrangement reactions of 3H-pyrazoles

Cited by 45 publications

References 25 publications

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

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

Multifold Photocyclization Reactions of Styrylcalix[4]arenes

Tetrahydropentalene

Contact Info

Product

Resources

About

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

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