General One-Pot, Three-Step Methodology Leading to an Extended Class ofN-Heterocyclic Cations:  Spontaneous Nucleophilic Addition, Cyclization, and Hydride Loss

Abstract

A new class of phenanthridinium derivative has been isolated from the reaction of 2-bromoethyl-phenanthridinium bromide with a range of primary amines in excellent yields. The reaction pathway is unprecedented and proceeds via three cascade steps: nucleophilic attack of a primary amine on the iminium moiety of a heteroaromatic ring system and cyclization to form a five-membered ring, followed by hydride loss to yield a rearomatized dihydro-1H-imidazo[1,2-f]phenanthridinium derivative. A range of NMR phase transfer experiments were carried out to elucidate the mechanistic pathway, and the methodology has been further developed by means of a biphasic system using N-bromosuccinimide as a co-oxidizing agent. The method has also been extended to other N-heterocyclic cation derivatives such as quinolinium and quinazolinium.

A Mixed‐Valence Manganese Cubane Trapped by Inequivalent Trilacunary Polyoxometalate Ligands

“…[20] Immersion of a single crystal of 1 in a droplet of dilute 6 mmol dihydroimidazophenanthridinium (DIP) [21] in water results in the formation of microtubes after approximately 30 seconds. Tubes grew rapidly with little directional stability and had overall diameters of 1-2 mm (see Figure 5).…”

“…Since the tube growth direction can be controlled, these tubular systems could be used to form complex patterns for catalytic device manufacture, especially if photoactive cations are employed. [22] To conclude, we have synthesized an unprecedented trimeric POM cluster [K 18 [Mn [21] The wandering pattern of growth arises from the relatively high solubility of 1 in the DIP solution.…”

A green and convenient approach for the synthesis of 1,10-phenanthrolines via a catalyst- and solvent-free condition

“…The precipitated solid was filtered and purified by column chromatography from ethyl acetate and n-hexane. 1,4-dihydro-2-methyl-4-(3-nitrophenyl)-N-phenyl-1,10-phenanthroline-3-carboxamide (5f): 1 …”

“…Recent challenges in modern organic chemistry encompass the development of methodologies that afford assembly of molecular complexity and diversity in a fewer steps from readily available starting materials, under green conditions and with high yields (1)(2)(3)(4)(5). For this purpose, multicomponent domino reactions (MDRs) play an increasingly important role for the synthesis of chemically and biologically important compounds because of their high degree of atom economy, convergence, productivity, ease of execution, excellent yields, and green chemistry characteristic (6)(7)(8)(9)(10)(11)(12).…”

An efficient synthesis and in vitro antibacterial evaluation of ruthenium–quinolinol complexes

“…1 These compounds and their modified scaffolds have widely been employed as pharmacophores for preparing a variety of drugs. 2 Recent efforts in organic synthesis was involved in the development of new methodologies for the preparation of structurally unique & complex heterocycles from relatively simple starting materials with fewer synthetic steps [3][4][5][6] , and the maintain of environment friendly reaction condition with operational simplicity. 7 Quinoline is a key structure in several compounds of therapeutic importance.…”