Manuel Finkelstein

CANTHINE ANALOGS VIA INTRAMOLECULAR DIELS-ALDER REACTIONS

Abstract Carbocyclic analogs ( 10 and 12 ) of canthine ( 1 ) and canthin-6-one ( 2 ) were prepared in three and four steps, respectively, from indole-3-car☐aldehyde. The key step was an intramolecular Diels-Alder reaction carried out in refluxing sulfolane.

Electrochemical Degradation of Aryl Sulfonium Salts

The products of the electrochemical degradation of several aryl sulfonium salts at an aluminum cathode were studied. In each case a phenyl radical was cleaved with the subsequent formation of benzene. Dimethylformamide was found to be an excellent solvent for these reactions. The rate of formation of benzene in the electrochemical decomposition of triphenylsulfonium trifluoroacetate in dimethylformamide has been shown to be independent of the concentration of sulfonium salt. A brief discussion of the mechanism is presented with reference to the observed current efficiency.

The amide-phenol ratios and structures in amide-picric acid complexes

Abstract Picric acid forms solid, isolable complexes with amides, with the amide-phenol ratio in these complexes being 1:1 for N,N-dialkylsubstituted amides and lactams and 2:1 for N-monoalkylsubstituted amides. With acetamide a 3:1 complex was also obtained, but this was unstable and changed over the 2:1 complex. It is suggested that these complexes result primarily from H-bonding interactions, and that in solution charge-transfer and proton-transfer structures also contribute.

The electrochemical reduction of succinimide : Reactivity of quaternary ammonium ions under electrolysis conditions

Abstract A solution of succinimide in ether acetonitrile or N, N-dimethylformamide containing tetra-n-butylammonium fluoborate shows a single, irreversible reduction wave at a platimum cathode by cyclic voltammetry. Coulometry demonstrates that a single electron is transferred. The reaction is accompanied by the evolution of hydrogen at a rate such that the passage of one Faraday of charge results in the generation of almost exactly 0.5 mole of hydrogen. The product of these reactions is the succinimide anion which is stable in the electrolysis solution, but reacts with tetra-n-butylammonium ion during vpc analysis or in refluxing N, N-dimethylformamide to form N-n-butylsuccinimide.

Oxidation of Benzylamines to Amides

Abstract A convenient method for the conversion of tertiary benzylamines to benzamides by phase transfer oxidation is described. Yields are good. Regioselectivities are reported.

Hydrogen-bonded complexes. 5. Phenol-amine complexes

Formation de complexes 2:1, 3:2, 3:1 entre des diphenols (hydroquinone, pyrocatechol, resorcinol, naphtalenediol-2,3) et des alkyl-, dialkyl- et trialkyl-amines

Protodediazoniation of Aryldiazonium Fluoroborates by Dimethylformamide [1]

Abstract The protodediazoniation of aryldiazonium fluoroborates can be effected by warm dimethylformamide (DMF). The conversion of 4-nitrobenzenediazonium fluoroborate to nitrobenzene was studied in detail. Products derived from trapping experiments were consistent with a homolytic process. Studies with deuterated DMF established that H atom abstraction occurred from both sites in DMF with a formyl:methyl preference of 3.5:1.0. This mechanism was consistent with bond energies and kinetic isotope effects calculated for the DMF radical cation.

Hydrogen bonded complexes IV : Urea-phenol complexes

Abstract A number of crystalline, hydrogen-bonded complexes of ureas and phenols are reported. The most commonly observed urea-phenol ratio is 1:1, but some complexes with ratios of 2:1, 1:2 and 1:3 were encountered. The structures of these complexes are discussed and one degradative reaction is described.

The N-bromosuccinimide-succinimide anion complex, an intermediate in the electron transfer mediated reduction of N-bromosuccinimide by succinimide anion

Abstract Complexes between N-bromosuccinimides and succinimide anions are shown to be intermediates in the reduction of N-bromosuccinimides, and a method for their synthesis as tetra-n-butylammonium salts is described.

A new synthesis of cis-bicyclo(4.2.0)octane-7,8-diol

Abstract A convenient electrochemical preparation of cis-bicyclo(4.2.0)octaine-7,8-diol from cyclooctatetraene is described. When the reduced electrolysis product from cyclooctatetraene is hydrolysed with methanol and hydrochloric acid the cis-diol is not isolated because of the intermediate formation of the acetal from cycloheptanecarboxaldehyde and the cis-diol.