نتایج جستجو برای: sulfonatocalix4 arene

تعداد نتایج: 2973  

Journal: :Journal of the American Chemical Society 2010
Derek J Schipper Marieke Hutchinson Keith Fagnou

The rhodium(III)-catalyzed hydroarylation of internal alkynes is described. Good yields are obtained for a variety of alkynes, and excellent regioselectivity is observed for unsymmetrically substituted alkynes. The reaction also gives good yields for a range of arenes. Preliminary mechanistic investigations suggest that this reaction proceeds through arene metalation with the cationic rhodium c...

2017
Gregory J P Perry Igor Larrosa

The beginning of the 21st century has seen tremendous growth in the field of decarboxylative activation. Benzoic acid derivatives are now recognised as atom-economic alternatives to traditional cross-coupling partners, and they also benefit from being inexpensive, readily available and shelf-stable reagents. In this microreview we discuss recent developments in the coupling of benzoic acid deri...

Journal: :Acta Crystallographica Section C: Crystal Structure Communications 2008
Harinandini Paramahamsan Anthony J. Pearson Nathalie M. Pinkerton A. Alan Pinkerton

The tricarbonylchromium unit bound to the arene ring of the chiral title complex, [Cr(C(19)H(26)O(3))(CO)(3)], is rotated by ca 25 degrees in agreement with the proposed mechanism for 1,5-asymmetric induction of nucleophilic attack.

Journal: :Chemical communications 2012
Minsik Min Sungwoo Hong

An efficient method for the C4-regiocontrolled C-H functionalization of coumarins to enable facile oxidative cross-couplings with simple arene components is disclosed.

Journal: :international journal of environmental research 2011
h. bagheri sadeghi h. sid kalal h. hoveidi z. molavi n. adeli asl

a new cesium ion selective pvc membrane based on parent calix [4] arene was developed for potentiometric determination of cesium in environmental samples. the electrode based on p-5,11,17,23tetra(tertbutyl) 25,26,27,28-tetrahydroxy calix[4]arene(thc) as ionophor ,dibutyl phthalate (dbp)as plasticizer ,sodium tetra phenyl borate(natpb)and oleic acid as lipophilic salt and additive showed the ...

Journal: :Journal of the American Chemical Society 2011
Sibo Lin Michael W Day Theodor Agapie

Nickel hydrides supported by a terphenyl diphosphine were synthesized and found to undergo nickel-to-arene H-transfers. Some of the resulting complexes also undergo the reverse (C-to-Ni) H-migration, indicating the potential for storing H-equivalents in this type of pincer ligand. NMR spectroscopy, single crystal X-ray diffraction, and isotopic labeling studies investigating the mechanism of th...

2008
Bahtier Ibragimov Edwin Weber Max Peukert Conrad Fischer Wilhelm Seichter

In the crystal structure of the title compound, C(12)H(12)N(2), the mol-ecule is twisted around the central C-C bond, with a dihedral angle of 8.32 (5)° between the mean planes of the pyridyl rings. The crystal structure is stabilized by arene stacking inter-actions, with a distance of 3.81 (1) Å between the ring centroids.

2011
Jörg Tellenbröker Dietmar Kuck

The syntheses of tribenzotriquinacenes (TBTQ) bearing three phenylurea groupings at either the arene periphery or at the benzhydrylic bridgeheads of the rigid, convex-concave, C(3) (v)-symmetrical molecular framework are reported. (1)H NMR data point to supramolecular aggregation of these TBTQ derivatives in low-polarity solvents.

Journal: :Journal of the American Chemical Society 2007
David R Stuart Elisia Villemure Keith Fagnou

An increasing emphasis on waste minimization has prompted research aimed at replacing common synthetic techniques with greener alternatives. In biaryl synthesis, direct arylation1,2 is an emerging alternative to Suzuki and Stille couplings;3 however, a more efficient strategy would involve the direct catalytic crosscoupling of two arenes without recourse to stoichiometric activating groups (eq ...

Journal: :Chemical communications 2008
Bao-Yong Hou Qi-Yu Zheng De-Xian Wang Zhi-Tang Huang Mei-Xiang Wang

In the presence of K(2)CO(3) in refluxing THF, dichloro-substituted tetraoxacalix[2]arene[2]triazine, a readily available macrocyclic compound from cyanuric acid chloride and benzyl 1,3-dihydroxybenzoate, underwent highly efficient nucleophilic displacement reactions with bis-nucleophilic reagents of different geometry, length and chirality in a 2+2 fashion to produce large and size-tunable cav...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید