4,5-Dichloro-1,2,3-dithiazolium chloride (appel´s salt): Reactions with N-nucleophiles

Different N-nucleophiles have been reacted with 4,5-dichloro-1,2,3-dithiazolium chloride (Appel's Salt), producing imines containing the 1,2,3-dithiazole ring.The authors wish to express sincere gratitude to Prof. C.W. Rees for his support and advice during the stay of A.M.C at the I.C. and to the Ministerio de Educación y Ciencia for providing a grant

Microwave-assisted parallel synthesis of a 2-aryl-1H-isoindole-1,3-dione library

An efficient parallel synthesis of a representative 28-member library of phthalimides is described. Parallel chromatography afforded the library members in suitable purity and with high yields

Efficient functionalization of quinolizinium cations with organotrifluoroborates in water

An efficient functionalization of the quinolizinium system is reported. The reaction of the four isomeric bromoquinolizinium salts with different organotrifluoroborates afforded alkyl-, vinyl-, aryl-, and heteroaryl quinolizinium derivatives in moderate or good yields. Reactions are carried out in water using a counterion exchange for the isolation of the cationic-coupled compounds.Comunidad de Madri

New route to pyrido[1,2-b]pyridazinium inner salts. Evidence of a 1,3-dipolar cycloaddition-ring expansion process

2-Alkoxycarbonylpyridinium N-aminides behave as 1,3-dipoles when reacted with Michael accepters, giving rise to the corresponding cycloadducts which, depending on their regioisomeric nature, subsequently undergo a ring expansion to give pyrido[1,2-b]pyridazinium inner salts.We wish to express our thanks to the Comisión Interministerial de Ciencia y Tecnología (CICYT, project PM97-004) and to the Ministerio de Educación y Ciencia for a grant to one of us (J.V.M)

2-Alkoxycarbonylcycloimmonium ylides, efficient 1,4-dipole equivalents in the synthesis of new conjugated betaines

Several heterocyclic mesomeric betaines containing the bicyclic systems pyrido[1,2-a]pyrazine and pyrido [2,1-f][1,2,4]triazine have been prepared by reaction of 2-alkoxycarbonyl pyridinium N-ylides with phenyl isocyanate and isothiocyanate.We wish to express our thanks to the Comisión Interministerial de Ciencia y Tecnología (CICYT ) for financial support (Project PB90-0284), and to the Ministerio de Educación y Ciencia by a grant to one of us (A.M.C

Synthesis of new conjugated mesomeric betaines from alkoxycarbonylazinium salts

A new series of conjugated mesomeric betaines have been synthesized from the reaction of various aminoheterocycles with 2-methylthio-4-oxo-3-phenylpyrido[2,1-φ][1,2,4]triazinium iodide, itself prepared from 2-ethoxycarbonylpyridinium N-aminide. Some of the heterobetaines and salts obtained have been studied by 1H-NMR, and their structures have been confirmed by X-ray analysis. The crystal structures reveal unexpected complementary stabilizing interactions between some betaines and their salts.We wish to express our thanks to the Comisió Interdepartamental de Reçerca i Innovació Tecnológica (CIRIT) for financial support (Project QFN94-4619) and to the Ministerio de Educación y Ciencia for a grant to one of us (JVM)

Preparation of new benzimidazole derivatives from N-[(methylthio)thiocarbonylmethyl]azinium salts

A series of new N-[(methylthio)thiocarbonylmethyl] azinium salts has been synthesized by reaction of carbon disulphide and methyl iodide with the corresponding phenacylazinium salt in a two-phase system followed by acid treatment of the ylide thus obtained. Condensation of dithioster derivatives with o-phenylenediamines gave N-(benzimidazolylmethyl) azinium salts in good yields.Authors wish to thank Comión Asesora de lnvestigación Científica y Técnica (C.A.I.C.Y.T.) for financial support

Synthetic uses of 1-[(methylthio)thiocarbonylmethyl] pyridinium iodide. Synthesis of new benzimidazole derivatives

Reaction of 1-[(methylthlo)thiocarbonylmethyl]pyridinium iodide with substituted o-phenylenediamines gave 1-[(2’-benzimidazolyl)methyl]pyridinium salts which were acylated and mono- and dialkylated by standard procedures. In addition. 2-(1’-piperidinylmethyl)benzimidazole derivatives were prepared by reduction of pyridinium moiety with sodium dithionite.Comisión Asesora de Investigación Científica y Técnica-CAICY

Stille reaction on pyridinium cations

A novel unit based on pyridinium cations has been synthesized by the Stilie reaction and represents a model for development of molecular electronic devices

Enyne ring-closing metathesis on heteroaromatic cations

Cationic heteroaromatic enynes have been employed as substrates in enyne ring-closing metathesis, under an atmosphere of ethylene and using the Hoveyda-Grubbs catalyst, for the first time; the reaction affords new 1-vinyl- and 2-vinyl-substituted 3,4-dihydroquinolizinium salts, useful precursors for biologically relevant cations based on the quinolinizium system.The authors acknowledge support for this work from the Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica, Ministerio de Ciencia y Tecnología through project BQU2002-03578 and a grant from the Comunidad de Madrid (A. N.)