Lewis Base Stabilized Phosphanylborane

✍ Scribed by Karl-Christian Schwan; Alexey Y. Timoskin; Manfred Zabel; Manfred Scheer

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 356 KB
• Volume: 12
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.200600185

✦ Synopsis

Abstract

The abstraction of the Lewis acid from [W(CO)~5~(PH~2~BH~2~⋅NMe~3~)] (1) by an excess of P(OMe~3~)~3~ leads to the quantitative formation of the first Lewis base stabilized monomeric parent compound of phosphanylborane [H~2~PBH~2~⋅NMe~3~] 2. Density functional theory (DFT) calculations have shown a low energetic difference between the crystallographically determined antiperiplanar arrangement of the lone pair and the trimethylamine group relative to the PB core and the synperiplanar conformation. Subsequent reactions with the main‐group Lewis acid BH~3~ as well as with an [Fe(CO)~4~] unit as a transition‐metal Lewis acid led to the formation of [(BH~3~)PH~2~BH~2~⋅NMe~3~] (3), containing a central H~3~BPH~2~BH~2~ unit, and [Fe(CO)~4~(PH~2~BH~2~⋅NMe~3~)] (4), respectively. In oxidation processes with O~2~, Me~3~NO, elemental sulfur, and selenium, the boranylphosphine chalcogenides [H~2~P(Q)BH~2~⋅NMe~3~] (Q = S 5 b; Se 5 c) as well as the novel boranyl phosphonic acid [(HO)~2~P(O)BH~2~⋅NMe~3~] (6 a) are formed. All products have been characterized by spectroscopic as well as by single‐crystal X‐ray structure analysis.