Polycations. III. Synthesis of polyphosphonium salts for use as antibacterial agents

Several series of polyphosphonium salts have been prepared. These include those in which the cationic sites are located at regular intervals along a linear chain of defined length (“strings”) and those in which the cationic sites are in linkages arrayed in branching arms about a central focus unit (“balloons”). Similarly, polyphosphonium balloon arrays have been attached to a polystyrene backbone providing a material that can serve as an anionic exchange resin. Several of the resultant materials have demonstrated antibacterial activity, in systems analogous to those previously reported for simple functionalized polystyrene species, and continue to be investigated. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:495–502, 1998     

1,5-dimethyl-2,3,3,4-tetrachloro-1,5,2,4-diazadiphosphorinan-6-one and some derivatives. Part II

The title compound 1 was allowed to react with catechol, 2,3-dihydroxynaphthalene, tetrabromocatechol, resorcinol, saligenin, and 3,5-di-tert-butylcatechol in the presence of triethylamine to form compounds 4a–4d and 4f. Whereas the catechol derivative 4a, the naphthol derivative 4b, and the tetrabromocatechol derivative 4c could be readily obtained, the saligenin derivative 4d and the 3,5-di-tert-butylcatechol derivative 4f were found to be stable only in solution. Contrary to expectation, compound 4e was not formed in the reaction of 1 with resorcinol. The reaction of 1 with 1,2,4,5-tetrahydroxybenzene led to the pentacyclic derivative 4g. Reaction of hydroquinone with 1 led to the formation of the dimeric structure 4h. Crystal structure analyses of 4a and 4b show that the nine-membered rings adopt essentially identical “tub” conformations in which the P and O atoms are coplanar. The P-C-P angles (across the CCl₂ bridge) are wide (ca. 119°). © 1997 John Wiley & Sons, Inc.     

Macromolecular design of cationic polyelectrolytes on the chitosan basis for achievement of high antimutagenic efficiency at gamma-irradiation

A new approach to the problem of construction of efficient antimutagenic (at γ-irradiation) systems has been developed on the basis of the models- synthetic cationic polyelectrolytes- polyquaternary salts of diallyldimethyl-ammonium type.     

Direct Regioselective Dehydrogenation of α-Substituted Cyclic Ketones

We disclose a highly regioselective, catalytic one-step dehydrogenation of α-substituted cyclic ketones in the presence of 2,3-dichlorobenzo-5,6-dicyano-1,4-benzoquinone (DDQ). The high regioselectivity originates from a phosphoric acid-catalyzed enolization, selectively affording the thermodynamically preferred enol, followed by the subsequent oxidation event. Our method provides reliable access to several α-aryl and α-alkyl substituted α,β-unsaturated ketones.