Three- and Five-Membered Anionic Chains of Pnictogenylboranes.

An unprecedented family of three- and five-membered substituted anionic derivatives of parent pnictogenylboranes is herein reported. Reacting various combinations of the pnictogenylboranes H E'-BH -NMe (E'=P, As) with pnictogen-based nucleophiles MER1R2 (E=P, As; R1=H, R2= Bu; R1=R2=Ph; M=Na, K) allows for the isolation of the unsymmetrical products [Na(18-crown-6)][H E'-BH -EH Bu] (3: E=E'=P; 4: E=E'=As; 5: E=As, E'=P) and [M(C)][H E'-BH -EPh ] (7: E=E'=P, M=Na, C=18-crown-6; 8: E=E'=As; M=K, C=[2.2.

Oxidation of Substituted Phosphanylboranes with Chalcogens.

The elemental chalcogens sulfur, selenium, tellurium and bis(trimethylsilyl)peroxide as an oxygen source are applied for the oxidation of the phosphanylboranes Ph P-BH ⋅NMe (1) and tBuHP-BH ⋅NMe (2). The corresponding monooxidation products Ph P(X)-BH ⋅NMe (X=O-Te, 3 a-d) and tBuHP(X)-BH ⋅NMe (X=O-Te, 4 a-d) were obtained in good yields and comprehensively characterized by single crystal X-ray structure analysis, NMR, IR spectroscopy and mass spectrometry. The first oxidation step proceeds very selectively for all chalcogenides.

Anionic Chains of Parent Pnictogenylboranes.

We report on the synthesis and structural characterization of unprecedented anionic parent compounds of mixed Group 13/15 elements. The reactions of the pnictogenylboranes H E-BH ⋅NMe (1 a=P, 1 b=As) with phosphorus and arsenic centered nucleophiles of the type [EH ] (E=P, As) lead to the formation of compounds of the type [H E-BH -E'H ] (2: E=E'=P; 3: E=E'=As; 4: E=P, E'=As) containing anionic pnictogen-boron chain-like units. Furthermore, a longer 5-membered chain species [H As-BH -PH -BH -AsH ] (5) and a cyclic compound [NHC -H B-PH -BH -NHC ] [P B H ] (6) containing a n-butylcyclohexane-like anion were obtained.