Cationic Chains of Parent Arsanylboranes and Substituted Phosphanylboranes

5 years ago

Cationic Chains of Parent Arsanylboranes and Substituted Phosphanylboranes

Alexander V. Virovets, Josef Baumann, Gábor Balázs, Christian Marquardt, Manfred Scheer

The substituted monomeric phosphanylboranes Ph2P−BH2⋅NMe3 (1) and tBuHP−BH2⋅NMe3 (2) have been used for the synthesis of cationic chain compounds built up by R2P−BH2 units. With a simple synthesis route, the highly stable cations [Me3N⋅H2B−PR1R2−BH2⋅NMe3]+ (1 a, 2 a) and [Me3N⋅H2B−PR1R2−BH2−PR1R2−BH2⋅NMe3]+ (1 b, 2 b) (R1=R2=Ph; R1=H, R2=tBu) are obtained as iodide (I−) salts. The reaction of H2As−BH2⋅NMe3 (3) with IBH2⋅SMe2 leads to [Me3N⋅H2B−AsH2−BH2−AsH2−BH2⋅NMe3][I] (3 a), the longest so far known arsanylborane chain. Compound 3 a reacts with acetonitrile through a formal hydroarsination reaction to form [cyclo-{As(BH2⋅NMe3)(CMe=NH)2(BH2)}][I] (4). The reported synthetic strategy has proved to be a powerful tool for the formation of small, cationic oligomeric units. All products were comprehensively characterized by X-ray structure analysis, NMR, IR spectroscopy, and mass spectrometry in cooperation with DFT calculations. Cationic inorganic chains: The synthesis of oligomeric, cationic group 13/15 compounds was successfully extended to organosubstituted phosphanylboranes. Furthermore, the longest so far known chain with a backbone consisting of alternating B and As atoms was obtained, which was converted into a heterocycle by a hydroarsination reaction with acetonitrile.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201702384