Insertion of CS2 into a Phosphorus–Arsenic Single Bond and Investigations on Phosphane Arsanyldithiocarboxylates

Bresien Jonas, Schulz Axel, Szych Lilian Sophie, Villinger Alexander, Wustrack Ronald

Abstract

The synthesis and reactivity of sterically demanding phosphaarsanes TerR1P–AsR2 (3) is described. These species were selectively synthesized via metathesis reactions of Ter-stabilized [Ter = 2,6-bis(2,4,6-trimethylphenyl)phenyl] potassium phosphides TerR1PK (1) with the N-heterocyclic chloroarsane ClAs{N(tBu)CH2}2 (2). Conversion of the n-butyl-substituted phosphaarsane 3c with the reactive heterocumulene CS2 leads to an insertion into the P–As bond, yielding the phosphane arsanyldithiocarboxylate TerR1P–C(S)S–AsR2 (4c) as a new structural motif. Because full conversion of 3c with CS2 requires long reaction times, an alternative synthetic route is reported herein, involving the conversion of 2 with phosphane dithiocarboxylates TerR1–C(S)SK (5), enabling synthetic access to a wider range of phosphane arsanyldithiocarboxylates. These interpnictogen dithiocarboxylates show an interesting bonding situation with a significantly elongated As–S bond due to negative hyperconjugation within the molecule. All products along the reaction path were fully characterized.