Acyl-und Alkylidenarsane, V [1] (Dimethylaminomethyliden)-phenylar8an, ein acyclisches Alkylidenarsan / Acyl-and Alkylidenearsines, V [1] (Dimethylaminomethylidene)-phenylarsine, an Acyclic Alkylidenearsine

Abstract

<jats:title>Abstract</jats:title><jats:p> Alkylidenearsines, Aminomethylidenearsines, Barrier of Rotation In the absence of a catalyst phenyl-bis(trimethylsilyl)arsine (1 a) reacts only very slowly with excess dimethylformamide (4) to give (dimethylaminomethylidene)-phenylarsine (8 a) and hexamethyldisiloxane (5). In the presence of small amounts of solid sodium hydroxide, however, the reaction is already finished after four days at + 20 °C. Similarly, lithium phenyltrimethylsilylarsenide · DME (2 a), which can easily be obtained from la and methyllithium in 1,2-dimethoxyethane (DME), and dimethylformamide (4) also form the alkylidenearsine (3 a) and lithium trimethylsilanolate. The NMR spectra of 3 a show the rotation of the dimethylamino group to be hindered with a barrier of about 63 kJ · mol<jats:sup>-1</jats:sup> .</jats:p>