104 / 2023-10-01 20:52:06

The Chemistry of New Bis-Carborano-Phosphines

ortho-Carborane, Phosphorus, Phosphine, Phosphorane.

Phosphorus in Synthetic Chemistry > 1) Phosphorus compounds as catalysts

Organophosphorus compounds play a significant role in synthetic organic chemistry and material science due to their chemical and physical properties. In the last few years, phosphorus-based cations, anions, and radicals have attracted a lot of attention due to their ability to activate different small molecules. A number of phosphonium and phosphenium cations and P-based radicals that served as catalysts in various reactions, providing an alternative or complement transition metal catalysts, were recently reported.

Our research interest lies in synthesizing novel P-based cations, anions, and radicals that are capable of activating small molecules and could further be used in catalysis. One of the approaches that we use is the substitution of P-center with the strong electron-withdrawing ortho carboranyl-based groups. For instance, we recently showed that phosphenium cation in ortho-carborane-based ligand can activate the H-H bond and catalyze for the hydrogenation reaction of C=C double bonds and fused aromatic systems.

In this work, we show the extension of this chemistry towards phosphonium cations and phosphoranyl radicals. Thus, we demonstrate here the progress that was made towards the synthesis of the desired [P]⁺ and [P]^• (Fig.1) substituted with a bis ortho-carboranyl group. In addition, some unexpected chemistry, which was obtained on the way towards [P]⁺ and [P]^•, will be presented.

Organophosphorus compounds play a significant role in synthetic organic chemistry and material science due to their chemical and physical properties. In the last few years, phosphorus-based cations, anions, and radicals have attracted a lot of attention due to their ability to activate different small molecules. A number of phosphonium and phosphenium cations and P-based radicals that served as catalysts in various reactions, providing an alternative or complement transition metal catalysts, were recently reported.

Our research interest lies in synthesizing novel P-based cations, anions, and radicals that are capable of activating small molecules and could further be used in catalysis. One of the approaches that we use is the substitution of P-center with the strong electron-withdrawing ortho carboranyl-based groups. For instance, we recently showed that phosphenium cation in ortho-carborane-based ligand can activate the H-H bond and catalyze for the hydrogenation reaction of C=C double bonds and fused aromatic systems.

In this work, we show the extension of this chemistry towards phosphonium cations and phosphoranyl radicals. Thus, we demonstrate here the progress that was made towards the synthesis of the desired [P]⁺ and [P]^• (Fig.1) substituted with a bis ortho-carboranyl group. In addition, some unexpected chemistry, which was obtained on the way towards [P]⁺ and [P]^•, will be presented.