Studies on a Novel Type of B(C6F5)3 and Aromatic Ammonium Chloride System

Although in recent years the frustrated Lewis pairs (FLPs) reactivity towards small molecule activation has been widely concerned, the reports on the FLPs derived from aromatic amines are few. This paper describes a new facile route to the aromatic amine based FLPs starting from aromatic amine hydrochloride/tri(pentafluorophenyl)borane (BCF) as a combined active couple and hydridosilane as a source of the hydride. The reaction characteristics have been studied for a set of the stoichiometrical reactions. The difference between the alkyl amine hydrochloride/BCF and aromatic amine hydrochloride/BCF systems is that after reacting with the silanes the formed aromatic ammonium hydridoborates [Ar2NH2](+) [HBCF](-) are not thermally stable and immediately release H-2 with formation of the corresponding amine and BCF. However, it is precisely because of this fact making this system applicable for a catalytic reaction a novel efficient chlorination reaction of hydridosilanes, which could be considered as the first example of the nonmetal catalytic reactions of the type, with the aromatic amine hydrochloride as a function of the chlorination reagent and BCF as a catalytic activator. The chlorination products and reaction mechanism have been also explored in detail under different ratios of silanes and aromatic amine hydrochlorides. Remarkably, if required, the initial aromatic amine hydrochloride can be regenerated and recycled by a simple reaction with gaseous HCl. This makes the reaction rather attractive from the viewpoint of "green chemistry".