Synthetic strategies of gold(I)-selenolates from ortho-substituted diaryl diselenides via selenol and selenenyl sulfide intermediates

• A synthetic strategy for gold(I)-selenolate complexes from diaryl diselenides is proposed.
• Detailed structural investigations of selenenyl sulfides and gold(I)-selenolates were carried out.
• Ortho-coordinating groups and oxidation state of Se-center were crucial for ligand exchange.
• Way out from unwanted thiol exchange was speculated using certain special conditions.

In the present study we describe the synthetic strategies to gold(I)-selenolate complexes by the reaction of ortho-substituted diaryl diselenides and electrophilic anti-arthritic gold(I)-compounds in the presence of thiol such as PhSH. Diselenides react with thiol to generate a mixture of selenol and selenenyl sulfide. While selenols react with electrophilic Au(I) compounds to form gold(I)-selenolate complexes, the selenenyl sulfides do not react and therefore, a prior conversion of selenenyl sulfide to selenol is necessary for an effective formation of gold(I)-selenolate from diselenide. However, this process is associated with the ligand exchange reaction in selenenyl sulfide in the presence of PhSH that hampers the regeneration of selenol. The structural aspects as well as the mode of reactivities of selenenyl sulfides and the products (gold(I)-selenolates) were analyzed using experimental as well as computational methods. These studies indicated that the presence of ortho-coordinating donor groups and oxidation state of Se-center play crucial roles towards their reactivities. Density functional theory calculations were undertaken to determine the natural charges on heteroatoms and to find the site for nucleophilic attack related to ligand exchange reactions.

Synthetic strategies to gold(I)-selenolate complexes from ortho-substituted diaryl diselenides using anti-arthritic gold(I)-compounds in the presence of thiol such as PhSH and DTT are described. The structural aspects as well as the mode of reactivities of selenenyl sulfides and the products (gold(I)-selenolates) were analyzed using experimental as well as computational methods.Figure optionsDownload as PowerPoint slide