نتایج جستجو برای: r sulfonatocalix4 arene

تعداد نتایج: 449633  

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...

2011
K. N. Vennila K. Prabha K. J. Rajendra Prasad D. Velmurugan

In the title compound, C(32)H(27)N(3)O, the fused tetra-cycilc ring system is essentially planar [r.m.s. deviation = 0.07 (7) Å]. An intra-molecular N-H⋯π(arene) inter-action and a weak intra-molecular C-H⋯N hydrogen bond may influence the mol-ecular conformation. In the crystal, weak inter-molecular C-H⋯N hydrogen bonds link the mol-ecules into centrosymmetric dimers, forming R(2) (2)(14) moti...

2012
Li-Jing Zhang Ling-Ling Liu Qi-Kui Liu Dian-Shun Guo

The title thia-calix[4]arene derivative, C(36)H(34)Br(2)O(8)S(4), adopts an unusual pinched cone conformation with the prop-oxy-substituted benzene rings inclined inward [forming a dihedral angle of 33.4 (1)°] and with the brominated benzene rings bent outward, making a dihedral angle of 66.1 (1)°. In the crystal, the mol-ecules form chains along [001] via C-H⋯S hydrogen bonds and S⋯S contacts ...

2008
John F. Gallagher Katie Donnelly Alan J. Lough

The title compound, C(19)H(12)F(2)N(2)O(2), a 2:1 product of the reaction of 3-fluoro-benzoyl-chloride and 2-amino-pyridine crystallizes with a disordered 3-fluoro-benzene ring adopting two conformations [ratio of occupancies 0.959 (4):0.041 (4)]. In the crystal structure, there are no classical hydrogen bonds and inter-actions comprise C-H⋯O in the form 2(C-H)⋯O=C [with motif R(2) (1)(5)]; C-H...

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...

Journal: :Journal of the American Chemical Society 2002
Robert B Grossman Kazuyuki Hattori Sean Parkin Brian O Patrick Melissa A Varner

A cage-shaped N,N'-diacylaminal crystallizes from some aromatic solvents as "supramolecular chair cyclohexanes", squat cylindrical hexamers with approximate D3d symmetry containing two arene molecules, and from other aromatic and nonaromatic solvents as infinite tapes. A homologous diacylaminal crystallizes only as an infinite tape. The hexamers represent the first examples of cyclic hexamers h...

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