Milorad M. Rogic

The stereoselective synthesis of functionalized vicinal diamine systems by the double allylation reactions of “protected” 1,2-bis-imine precursors.

Abstract A diastereoselective synthesis of vicinal diamines via the reactions of allylic Grignard reagents with readily available “protected” 1,2-bisimines has been developed. This method has been extended to preparing optically pure diamines by the use of chiral 1,2-bisimine precursors.

Organoboranes for synthesis. 9. Rapid reaction of organoboranes with iodine under the influence of base. a convenient procedure for the conversion of alkenes into iodides via hydroboration

Abstract The reaction of organoborane with iodine is strongly accelerated by sodium hydroxide. Organoboranes derived from terminal alkenes react with the utilization of approximately two of the three alkyl groups attached to boron, providing a maximum of 67% yield of alkyl iodide. Thus, hydroboration-iodination of 1-decene gives a 60% yield of n -decyl iodide. Secondary alkyl groups, derived from internal alkenes, react more sluggishly and only one of the three alkyl groups attached to boron is converted to the iodide. Thus, the procedure applied to 2-butene provides a 30% yield of 2-butyl iodide. The use of disiamylborane bis -(3-methyl-2-butylborane, Sia 2 BH) as hydroborating agent increases the yield of iodides from terminal alkenes since the primary alkyl groups react in preference to the secondary siamyl groups. Consequently, hydroboration of 1-decene with Sia 2 BH, followed by iodination gives a 95% yield of n -decyl iodide. The use of methanolic sodium methoxide in place of sodium hydroxide provides alkyl iodides in considerably higher yields. The combination of hydroboration with iodination in the presence of a base provides a convenient method for the anti -Markovnikov hydroiodination of alkenes. The base-induced iodination of organoboranes proceeds with the inversion of configuration at the reaction center, as shown by the formation of endo -2iodonorbomane from tri- exo -norbomylborane.

Copper(II)-Induced Oxygenolysis of o-Benzoquinones, Catechols, and Phenols: The Active Copper(II)-Species, Role of Cupric Chloride, and the General Question of Activation of Molecular Oxygen by Dioxygenases

The chemical energy required by biological systems to do work is derived primarily by oxidation of complex organic molecules to carbon dioxide and water. Since, in the overall process, oxygen acts as a final acceptor of electrons from the substrates and is converted to water, a special mechanism for the activation of molecular oxygen is not required. Nevertheless, it is still not known with certainty whether the required four electrons are transferred between the last few members of the electron-transporting chain in pairs or singly, nor is it known precisely how molecular oxygen accepts the electrons from the last member of this chain (the cytochrome c oxidase). 1