Oxidative addition of allylic carbonates to palladium(0) complexes: reversibility and isomerization

The oxidative addition of a cyclic allylic carbonate to the palladium(0) complex generated from a [Pd(dba)2]+2 PPh3 mixture affords a cationic pi-allylpalladium(II) complex with the alkyl carbonate as the counter-anion. This reaction is reversible and proceeds with isomerization of the allylic carbonate at the allylic position. The equilibrium constant has been determined in DMF. The influence of the precursor of the palladium(0) is discussed.

Application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to the structure determination of medium and large macrocycles formed by palladium(0)-catalyzed allylation of arenesulfonamides, sulfamide, and cyanamide.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry allowed the direct determination of the extent of macrocyclic and linear oligomer formation in the palladium(0)-catalyzed allylation of highly acidic and non-nucleophilic arenesulfonamides, sulfamide, and cyanamide. Palladium-containing 15-membered-ring macrocyclic compounds gave unusual [M - H](+) ions besides [M + Na](+) and [M + K](+) adducts. Copyright 1999 John Wiley & Sons, Ltd.

Preparation, antimicrobial evaluation, and mutagenicity of [2-hydroxyaryl]-[1-methyl-5-nitro-1H-2-imidazolyl]methanols , [5-tert-butyl-2-methylaminophenyl]-[1-methyl-5-nitro-1H-2-imidazo lyl]me thanol, and [2-hydroxyaryl]-[1-methyl-5-nitro-1H-2-imidazolyl] ketones.

Efficient preparations of the titled compounds are described, their antimicrobial activity and mutagenic properties being evaluated. Some of the studied compounds are nonmutagenic and present a MIC as low as some of the usual standards in the field.