Indole Synthesis via Cyclative Formation of 2,3-Dizincioindoles and Regioselective Electrophilic Trapping

Upon zincation of two acidic protons attached to the nitrogen and the sp-carbon atoms, a <i>N-</i>protected 2-ethynylaniline cyclizes to a 2,3-dizincioindole at 120 °C. Driven by the energy gain due to formation of two C–Zn bonds, this reaction occurs smoothly without side reactions, although this transformation is intrinsically endothermic in its bare anionic form. The resulting dizinc intermediate can be functionalized with one or two different electrophiles either inter- or intramolecularly on either C² or C³ selectively, depending on the choice of catalyst and the electrophiles. This conversion of 2-ethynylaniline to 2,3-dimetalloindole can be applied to an expeditious synthesis of indenoindolone and benzodipyrrole derivatives, which are compounds of interest for medicinal chemistry and materials science, respectively

Conical Ionic Amphiphiles Endowed with Micellization Ability but Lacking Air–Water and Oil–Water Interfacial Activity

Micellization in water and reduction of the surface tension at water interfaces with air and oil are two archetypical properties of surfactants, caused by self-aggregation and Gibbs monolayer formation at the interfaces, respectively. We present here a new type of amphiphiles that possess a conical shape consisting of a hydrophobic apex and five ionic termini at the base of the cone. The conical shape and the high charge density cooperatively impede monolayer formation at the interfaces, hence preventing foaming and emulsification. On the other hand, the conical shape strongly assists micelle formation in water and hemimicelle formation on a solid surface to promote dissolution of nanoparticles such as magnetic nanoparticles and nanocarbons in water. The well-defined shape and charge locations distinguish the new amphiphiles from known polymer amphiphiles that show similar surface activity