A series of (S)-proline-based enantiopure phosphorus triamide derivatives were prepared and evaluated as HMPA alternative in samarium diiodide cyclization reactions N-acylated indole derivatives. The expected tricyclic indoline generally obtained good to excellent yields, however, the induced enantioselectivities at best moderate. In our model reaction, derivative with a (dimethyl)hydroxymethyl...

A series of 9,10-bis(phenylethynyl)anthracenes decorated with sterically demanding tert-butyl substituents have been prepared and spectroscopically characterised. We demonstrate that the introduction of two bulky substituents in the ortho position of the phenyl rings effectively locks the ground state into a conformation in which the three rings are orthogonal. Fluorescence spectroscopy reveals...

A new bulky biarylphosphine ligand (L8) has been developed that allows the Pd-catalyzed C-O cross-coupling of a wide range of aryl halides and phenols under milder conditions than previously possible. A direct correlation between the size of the ligand substituents in the 2', 4', and 6' positions of the nonphosphine containing ring and the reactivity of the derived catalyst system was observed....

The mol-ecular structure of the title compound, C(14)H(11)Cl(3)O(4)S, displays a biphenyl dihedral angle of 4.9 (2)° between the benzene rings, which is significantly smaller than the calculated dihedral angle of 41.2° of biphenyl derivatives without ortho substituents. The C(Ar)-O bond length of 1.432 (4) Å is comparable with other sulfuric acid biphenyl-4-yl ester 2,2,2-trichloro-ether ester ...

The photochemical version of the Boulton-Katritzky reaction has been studied, examining the behaviour of the arylhydrazones of 3-benzoyl-5-X-1,2,4-oxadiazoles. The effect of several modifications of the substrates structure (the E and/or Z structures of arylhydrazones, the possible presence of substituents in the arylhydrazono moiety, and the nature of substituents at C-5 of the 1,2,4-oxadiazol...

A new method is presented for calculation of electronegativities of groups, or substituents, or substructures of molecules. The method combines the electron energies of the valence orbitals of each atom in the fragment. It is a simple calculation, well-suited to computers, which can provide the electronegativities of elements, atoms, substituents, substructures, and ionic groups. It is especial...

IN THE TITLE COMPOUND [SYSTEMATIC NAME: 1(2),1(5)-dibromo-5(2),5(5)-dimethoxy-2,7-dithia-1,5(1,4)-dibenzenaoctaphane], C(18)H(18)Br(2)O(2)S(2), the dihedral angle between the aromatic rings is 0.6 (2)° and their centroid separation is 3.251 (2) Å, indicating that a trans-annular π-π interaction occurs. The dimeth-oxy and dibromo substituents are located at crossed positions because of the elect...