Reduction of potassium perchlorate in N,N-dimethylformamide (DMF) or dimethylsulfoxide (DMSO) produces the anion of the solvent which may deprotonate acids stronger than the solvent; the anion of DMF may also act as a reducing agent and/or a nucleophile. The anion of DMF reacts in DMF with acetophenone to 3-dimethylaminocarbonyl-1,5-diphenyl-1,5-pentanedione and some 1,5-diphenyl-1,5-pentanedione; similar products are obtained from fluorene. Benzalacetophenone reacts with DMF-anion/DMF to 2-benzoyl-1,3,4-triphenylcyclopentadiene. The DMF-anion/DMF reacts with benzyl phenyl sulfone to unsymmetrical 2,3-diphenylcyclopropyl phenyl sulfone. DMSO-anion (dimsyl)/DMSO deprotonates 2-bromoanisole with formation of a methoxybenzyne which can add a nucleophile, such as piperidine, in the 3-position. With DMF-anion/DMF and piperidine as nucleophile 1-piperidinecarboxaldehyde is formed. Electrogenerated dimsyl deprotonates 4-nitroethylbenzene; on reversal of the current in the same cell a mixture of d,l- and meso-2,3-bis(4'-nitrophenyl)butane is formed. (c) 2005 Elsevier B.V. All rights reserved.