The synthesis and properties of the diphenyl-substituted arsanylborane Ph2AsBH2SMe2 (1) and Ph2AsBH2NMe3 (2) stabilized by a Lewis base (LB) were reported. These compounds were obtained by reaction of KAsPh2 with IBH2−LB (LB=SMe2, NMe3). Compounds 1 and 2 were used as starting materials for oligomeric/ polymeric arsinoboranes. The neutral species, H3B−Ph2AsBH2NMe3 (3) and Br3B−Ph2AsBH2NMe3 (4), were synthesized by reaction with H3B and Br3B, respectively. Upon reaction with IBH2−LB (LB=SMe2, NMe3), the cationic oligomeric group-13/15-based compounds [(Me3NBH2AsPh2BH2NMe3)]I (5) and [H2B(Ph2AsBH2NMe3)2]I (6) were obtained. All compounds were completely characterized. In addition, the oxidation of Ph2AsBH2NMe3 with chalcogens was studied. The sulfur Ph2As(S)BH2NMe3 (7 b) and selenium Ph2As(Se)BH2NMe3 (7 c) oxidation products were both isolated and fully characterized, whereas the bis(trimethylsilyl)peroxide oxidated arsinoborane Ph2As(O)BH2NMe3 (7 a) was not stable enough and could only be characterized in solution. DFT computations supported the decomposition pathway of this compound.