A series of pyridinium and bipyridinium salts were prepared their catalytic properties evaluated in the aza-Diels-Alder reaction between imines Danishefsky diene. Depending on substituents pyridinium/bipyridinium rings nature counterion, two mechanisms activation demonstrated. In case non-substituted rings, substrate is activated through charge transfer involving aryl ring C-side imine. When ha...

A new class of boronium and borenium cations are prepared by reaction of pyridinium hydrochloride with pyridine stabilized borabenzene derivatives.

The title compound, C(6)H(10)N(2) (2+)·2Cl(-), contains a network of 4-(ammonio-meth-yl)pyridinium cations and chloride anions which are inter-connected by N-H⋯Cl hydrogen bonds. The crystal packing is also influenced by inter-molecular π-π stacking inter-actions between identical anti-parallel organic cations with a face-to-face distance of ca 3.52 Å.

In the title molecular salt, C(6)H(8)NO(+)·Cl(-), the packing is consolidated by N-H⋯Cl and O-H⋯Cl hydrogen bonds, resulting in the formation of [010] chains of alternating cations and anions.