The crystal structures of a series of 3,39-dinitro-2,29-bipyridine N-oxides and N,N9-dioxides consistently show 1,5 interactions between nitro oxygen atoms and aromatic carbon atoms ((ON)O...C: 2.623(2)–2.839(2) Å) while there are also 1,6 interactions between N-oxide oxygen atoms and nitro nitrogen atoms in most cases (O...N(O2): 2.737(2)–2.874(3) Å). The O...C interactions appears to be a com...

The ortho-, meta-, and para-trifluoromethylphenylhydrazine inhibitors of porcine plasma amine oxidase were synthesized. Titrations of plasma amine oxidase with these inhibitors demonstrated that 1 mol of trifluoromethylphenylhydrazine completely and irreversibly modifies 1 mol of enzyme by covalently binding to the active carbonyl cofactor. NMR relaxation measurements on the fluorine nuclei wer...

The aromatic polyketones 3a-d are versatile compounds for the synthesis of the multi-1,2,3-selenadiazole aromatic derivatives 1a-d. The preparation starts with the reaction between the multi-bromomethylene benzene derivatives 2a-d and 4-hydroxy- acetophenone to give compounds 3a-d which are transformed through the reaction with semicarbazide hydrochloride or ethyl hydrazine carboxylate into the...

Pyrazino compounds such as quinoxalines are 1,4-diazines with widespread occurrence in nature. Quinolin-8-amines are isomerically related and valuable scaffolds in organic synthesis. Herein, we present intramolecular main group metal Lewis acid catalyzed formal hydroamination as well as hydroarylation methodology using mono-propargylated aromatic ortho-diamines. The annulations can be conducted...

The title compound, C(14)H(12)N(2)O(2), is an ortho-rhom-bic polymorph of the previously reported monoclinic form [Bakir et al. (2005 ▶). Acta Cryst. E61, o1611-o1613]. The dihedral angle between the aromatic rings is 4.32 (13)°. The mol-ecular structures of the two polymorphs, including short intra-molecular O-H⋯O hydrogen bonds between the the hydr-oxy and keto groups, are quite similar but t...

a distinctive and general feature of gas-phase aromatic substitution, occurs only in those cases where the electrophile fulfils certain requirements. Paramount among the latter seem to be the presence of H atoms carrying a substantial fraction of the positive charge, capable of establishing localized H bonds with the unshared electrons of the substituent, as well as a suitable geometry of the c...

Photolysis of 1-o—toluyl-3,4-dihydroisoquinolines gives protoberberine alkaloids through the intermediacy of x-hydroxy quinodimethanes and spirobenzyl isoquinol ines. Ortho trimethylsilylmethyl benzoyl chlorides on treatment with fluoride ions afford ketene quinodimethanes which can be trapped with reactive dienophiles. The reactivity pattern of these intermediates is considered in terms of the...

A quantum circuit rule for combining quantum interference effects in the conductive properties of oligo(phenyleneethynylene) (OPE)-type molecules possessing three aromatic rings was investigated both experimentally and theoretically. Molecules were of the type X-Y-X, where X represents pyridyl anchors with para (p), meta (m) or ortho (o) connectivities and Y represents a phenyl ring with p and ...

The Bartoli indole synthesis is the treatment of an ortho-substituted nitro-aromatic compound with 3 equiv of vinylmagnesium bromide to give the 7-substituted indole,1,2 and this method has rapidly become the shortest and most flexible synthesis for indoles of this substitution pattern.1-5 We have recently reported an extension to this methodology, suggesting that it may not be limited exclusiv...

The metalloradical activation of ortho-benzallylaryl N-tosyl hydrazones with [Co(TPP)] (TPP=tetraphenylporphyrin) as the catalyst enabled the controlled exploitation of the single-electron reactivity of the redox non-innocent carbene intermediate. This method offers a novel route to prepare eight-membered rings, using base metal catalysis to construct a series of unique dibenzocyclooctenes thro...