Thallium in organic synthesis—XVI

McKillop, Alexander; Swann, Brian P.; Taylor, Edward C.

doi:10.1016/s0040-4020(01)93043-1

Cited by 70 publications

(21 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Dialkyne 2 and dibromide 3 have previously been synthesised. [9,10] A fresh solution of oxidising thalliumA C H T U N G T R E N N U N G (III) trifluoroacetate (0.44 mol dm À3 ) in trifluoroacetic acid was prepared as reported by McKillop et al [15] N 1 ,N 3 -bis(3-azidopropyl)isophthalamide (4): Dibromide 3 (2.00 g, 4.92 mmol) was dissolved in dry, degassed dimethylformamide (50 mL) and sodium azide (3.20 g, 10 equiv) was then added. The reaction mixture was stirred under a N 2 atmosphere at room temperature overnight and then added to H 2 O (250 mL).…”

Section: Methodsmentioning

confidence: 99%

Ion‐Pair Recognition by a Heteroditopic Triazole‐Containing Receptor

Picot

Mullaney

Beer

2012

Chemistry A European J

View full text Add to dashboard Cite

A new heteroditopic calix[4]diquinone triazole containing receptor capable of recognising both cations and anions through Lewis base and C-H hydrogen-bonding modes, respectively, of the triazole motif has been prepared. This ion-pair receptor cooperatively binds halide/monovalent-cation combinations in an aqueous mixture, with selectivity trends being established by (1)H NMR and UV/Vis spectroscopy. Cation binding by the calix[4]diquinone oxygen and triazole nitrogen donors enhances the strength of the halide complexation at the isophthalamide recognition site of the receptor. Conversely, anions bound in the receptor's isophthalamide cavity enhance cation recognition. (1)H NMR investigations in solution suggest that the receptor's triazole motifs are capable of coordinating simultaneously to both cation and anion guest species. Solid-state X-ray crystallographic structural analysis of a variety of receptor ion-pair adducts further demonstrates the dual cation-anion binding role of the triazole group.

show abstract

Section: Methodsmentioning

confidence: 99%

Ion‐Pair Recognition by a Heteroditopic Triazole‐Containing Receptor

Picot

Mullaney

Beer

2012

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…14 In conclusion we have developed a rapid and solventless method for cleavage of oxime compounds. 14 This limitation, however, can be circumvented by acetylation of the OH and NH 2 groups before the formation of oximes.…”

Section: Methodsmentioning

confidence: 99%

Conversion of Oximes into Carbonyl Compounds with Thalium(III) Nitrate Supported onto HZSM-5 Zeolite Under Microwave Irradiation in Solventless System

Heravi

Ghassemzadeh

2003

Phosphorus, Sulfur, and Silicon and the Related Elements

View full text Add to dashboard Cite

show abstract

“…Reaction of a solution of p‐tert ‐butylcalix[4]arene ( 1 ) in acetonitrile with propane‐1,3‐ditosylate, 1,4‐dibromobutane, or 1,5‐dibromopentane in the presence of potassium carbonate gave the bis(calix[4]arene) derivatives 2, 3 , and 4 in 30, 23, and 26 % yields, respectively (Scheme ). Oxidation of these compounds with Tl(OCOCF 3 ) 3 in trifluoroacetic acid4a, 7 gave the new bis(calix[4]diquinone) ionophores L 1 , L 2 , and L 3 in respective yields of 28, 10, and 9 % after column chromatography and recrystallization 8…”

Section: Methodsmentioning

confidence: 99%

Cesium- and Rubidium-Selective Redox-Active Bis(calix[4]diquinone) Ionophores

2001

View full text Add to dashboard Cite

The synthesis of redox-active molecular receptors designed to selectively recognize and electrochemically sense charged or neutral guest species of biological and environmental importance is an area of intense current interest. [1] A number of research groups have incorporated redox-active transition metal and organic centers into a variety of macrocyclic structural frameworks based on crown ethers, cryptands, and calixarenes, and shown some of these systems to be selective and electrochemically responsive to the binding of metal cations, particularly lithium, [2] sodium, [3] and potassium. [4] However, the construction of redox-active ionophores for the selective recognition of the larger cesium and rubidium metal cations has not, to our knowledge, been reported. This situation is surprising in view of the environmental concern for monitoring radioactive cesium in nuclear waste solutions [5] and the potential use of rubidium isotopes in radiopharmaceutical reagents. [6] We report here the synthesis, coordination, and electrochemical investigations of novel bis(calix[4]diquinone) receptors L 1 and L 2 , and demonstrate their remarkable ability to selectively complex and electrochemically sense cesium and rubidium cations.Reaction of a solution of p-tert-butylcalix[4]arene (1) in acetonitrile with propane-1,3-ditosylate, 1,4-dibromobutane, or 1,5-dibromopentane in the presence of potassium carbonate gave the bis(calix[4]arene) derivatives 2, 3, and 4 in 30, 23, and 26 % yields, respectively (Scheme 1). Oxidation of these compounds with Tl(OCOCF 3 ) 3 in trifluoroacetic acid [4a, 7] gave the new bis(calix[4]diquinone) ionophores L 1 , L 2 , and L 3 in respective yields of 28, 10, and 9 % after column chromatography and recrystallization. [8] Electrospray mass spectrometry (ES-MS) competition experiments gave the first qualitative indication that L 1 and L 2 displayed notable selectivity preferences for Cs and Rb ions. The electrospray mass spectra of equimolar Group 1 metal iodides in the presence of solutions of the tetraquinone ligands in DMSO revealed the most intense peaks occurred at [6] T.

show abstract

Thallium in organic synthesis—XVI

Cited by 70 publications

References 30 publications

Ion‐Pair Recognition by a Heteroditopic Triazole‐Containing Receptor

Ion‐Pair Recognition by a Heteroditopic Triazole‐Containing Receptor

Conversion of Oximes into Carbonyl Compounds with Thalium(III) Nitrate Supported onto HZSM-5 Zeolite Under Microwave Irradiation in Solventless System

Cesium- and Rubidium-Selective Redox-Active Bis(calix[4]diquinone) Ionophores

Contact Info

Product

Resources

About