- Synthesis of meta and para-substituted aromatic sulfonate derivatives of polydentate phenylazaphosphinate ligands: Enhancement of the water solubility of emissive europium(III) EuroTracker dyes
-
The synthesis is described of a series of meta and para-substituted phenylsulfonate derivatives of very bright Eu(III) complexes with arylphosphinate groups and strongly absorbing arylalkynylpyridine moieties. The synthetic route involved the early introduction of trifluoroethyl esters to protect the sulfonic acid group, withstanding the use of reagents including acetyl bromide and mCPBA, and tolerating acid-catalysed esterification and Sonogashira reaction conditions. The Eu(III) complexes exhibit enhanced water solubility; their photophysical properties are not perturbed significantly by introduction of the anionic sulfonate groups.
- Delbianco, Martina,Lamarque, Laurent,Parker, David
-
-
Read Online
- Very bright, enantiopure europium(III) complexes allow time-gated chiral contrast imaging
-
Chiral image contrast is demonstrated using enantiopure Eu(iii) complexes that emit right or left-handed circularly polarised light of opposite sign, at selected wavelengths.
- Frawley, Andrew T.,Pal, Robert,Parker, David
-
supporting information
p. 13349 - 13352
(2016/11/18)
-
- Aerobic oxynitration of alkynes with tBuONO and TEMPO
-
An efficient method for stereoselective nitroaminoxylation of alkyne has been reported. The reaction enjoys a broad substrate scope, good functional group tolerance, and high yields. Synthetically useful α-nitroketones can be accessed through these products in a single step.
- Dutta, Uttam,Maity, Soham,Kancherla, Rajesh,Maiti, Debabrata
-
supporting information
p. 6302 - 6305
(2015/02/19)
-
- Terminal alkynes from aldehydes via dehydrohalogenation of (Z)-1-iodo-1-alkenes with TBAF
-
Terminal alkynes were prepared in near quantitative yields via dehydrohalogenation of (Z)-1-iodo-1-alkenes with tetrabutylammonium fluoride (TBAF) under mild conditions. The methodology was expanded to include a one-pot, direct synthesis of terminal alkynes from aldehydes without the necessity of isolating and purifying the intermediate iodoalkene.
- Beshai, Mira,Dhudshia, Bhartesh,Mills, Ryan,Thadani, Avinash N.
-
supporting information; experimental part
p. 6794 - 6796
(2009/04/07)
-
- Vinyl Cation Intermediates in Solvolytic and Electrophilic Reactions. 1. Solvolysis of α-Arylvinyl Derivatives
-
The solvolysis of 16 α-arylvinyl tosylates, bromides, and chlorides has been investigated in various alcohol-water mixtures and in acetic acid at several temperatures.All substrates were substituted with either 2-methyl or 2,6-dimethyl groups to accelerate the rates of reaction.The major or exclusive product isolated in most cases was the acetophenone arising from hydrolysis of the expected enol ethers or acetates during workup.The kinetics were simple first order in the vast majority of cases, with excess base added to prevent side reactions.Leaving group effects, Winstein-Grunwald m values, Schleyer Q values, and effects of solvent nucleophilicity all point to a limiting SN1 ionization generating a vinyl cation intermediate, in which there is little rear-side nucleophilic assistance by solvent.Substituent effects led to ρ values in the range -3.9 to -5.3 vs. ?+.Activation parameters are typical for an SN1 process, and ΔS% is insensitive to the presence of zero, one, or two o-methyl groups, as are the effects of solvent polarity on the rates.The results should therefore be directly comparable with other solvolytic or electrophilic reactions generating formally similar vinyl cation intermediates.
- Yates, Keith,Mandrapilias, George
-
p. 3892 - 3902
(2007/10/02)
-