Polycations. II. Chiral ammonium dendrimer synthesis

Glycoside-Based Ionic Liquids

“…These "polycations" were of particular interest given our involvement in the construction and use for a variety of purposes of polyammonium and polyphosphonium salts. Polyammonium and polyphosphonium salts in several geometric categories were prepared, including dendrimers (Rengan & Engel 1990;Engel et al 1991;Engel 1992;Rengan & Engel 1992;Engel et al 1993a;Engel et al 1993b;Engel 1995;Cherestes & Engel 1994;Cherestes et al 1998), linear cationic arrays, "strings" (Fabian et al 1997;Shevchenko & Engel 1998;Strekas et al 1999;Engel et al 1999;Cohen et al 1998;Gordon et al 2006), and cyclic systems, "rings" Cohen et al 2000a;Cohen et al 2000b). Examples of these categories of polycationic species are illustrated in Figures Efforts using the cyclodextrins led to increasing interest in a variety of carbohydrate monoand polycationic species.…”

“…In such a situation their formation of a simple crystalline structure at room temperature is disfavored and a liquid or glass material is to be anticipated. Indeed, one of the first ionic liquids generated in our laboratory was that from a derivative of a polyhydroxylic species as a chloride (Cherestes et al 1998). In this effort, formation of a chiral ammonium salt derived from (S)-malic acid by reaction of the primary chloride with 1,4-diazabicyclo[2.2.2]octane produced the chloride salt as a viscous liquid that resisted all attempts at crystallization (Figure 6).…”