János Balogh

Synthesis of steroid-ferrocene conjugates of steroidal 17-carboxamides via a palladium-catalyzed aminocarbonylation - Copper-catalyzed azide-alkyne cycloaddition reaction sequence

Steroids with the 17-iodo-16-ene functionality were converted to ferrocene labeled steroidal 17-carboxamides via a two step reaction sequence. The first step involved the palladium-catalyzed aminocarbonylation of the alkenyl iodides with prop-2-yn-1-amine as the nucleophile in the presence of the Pd(OAc)(2)/PPh(3) catalyst system. In the second step, the product N-(prop-2-ynyl)-carboxamides underwent a facile azide-alkyne cycloaddition with ferrocenyl azides in the presence of CuSO(4)/sodium ascorbate to produce the steroid-ferrocene conjugates. The new compounds were obtained in good yield and were characterized by (1)H and (13)C NMR, IR, MS and elemental analysis.

Synthesis of ferrocene-labeled steroids via copper-catalyzed azide-alkyne cycloaddition. Reactivity difference between 2β-, 6β- and 16β-azido-androstanes

Copper-catalyzed cycloaddition of steroidal azides and ferrocenyl-alkynes were found to be an efficient methodology for the synthesis of ferrocene-labeled steroids. At the same time, a great difference between the reactivity of 2β- or 16β-azido-androstanes and a sterically hindered 6β-azido steroid toward both ferrocenyl-alkynes and simple alkynes, such as phenylacetylene, 1-octyne, propargyl acetate and methyl propiolate, was observed.

Synthesis of Ferrocenoyl L-Arginine Derivatives by Homogeneous Catalytic Carbonylation

Abstract Ferrocene–labeled arginine derivatives with different structures were synthesized via homogeneous catalytic carbonylation. Aminocarbonylation of iodoferrocene in the presence of L-arginine methyl ester or Nα-benzoyl-L-arginine ethyl ester as N-nucleophiles led to triacyl derivatives as the main products. The formation of diacyl compounds was also observed, but no monoacyl derivative could be isolated from the reaction mixture of iodoferrocene and L-arginine methyl ester.