Tetrachlorocatecholates of triarylarsines as a novel class of Lewis acids.

Pnictogen-mediated Lewis acidity is an emerging research subject in organic chemistry, supramolecular chemistry, etc. In contrast to the extensive studies on phosphorus and antimony, the diversity of arsenic-Lewis acids was quite limited. Herein, tetrachlorocatecholates of triarylarsines were newly synthesized. Their structures, electronic properties, and Lewis acidities were experimentally and computationally examined and compared with the corresponding phosphorus and antimony analogs. This is the first systematic study on the relationship between the structure and Lewis acidity of arsenic-mediated Lewis acids.

Tertiary arsine ligands for the Stille coupling reaction.

The Stille coupling reaction is one of the most important coupling reactions. It is well known that the triphenylarsine ligand can accelerate the reaction rate of Stille coupling. However, other arsine ligands have never been investigated for the Stille coupling reaction so far. In this work, we prepared 13 kinds of C3-symmetrical tertiary arsine ligands and discovered that tri(p-anisyl)arsine is the best ligand for the reaction of tributylvinyltin and p-iodoanisole. The reaction mechanism was studied by dispersion-corrected density functional theory calculations to demonstrate the energetic feasibility of the Stille coupling reactions mediated by tri(p-anisyl)arsine.