190836-00-1

Upstream product

• 6996-29-8 phenylphosphine-borane 
• 67-64-1 acetone 
• 13292-87-0 dimethylsulfide borane complex 
• 14044-65-6 borane-THF 
• 57483-31-5 ethyl (1?hydroxy?1?methylethyl)phenylphosphinate 
• 172487-18-2 ethyl Phenylphosphinate 

Relevant academic research and scientific papers

Chemoselective Reduction of the P=O Bond in the Presence of P–O and P–N Bonds in Phosphonate and Phosphinate Derivatives

Chemoselective reduction of the strong P=O bond in the presence of weaker P–O (ester) and P–N (amide) bonds in phosphonic acid derivatives has constituted an unresolved problem in organophosphorus chemistry for years. This long-standing problem is now solved for biologically relevant α-hydroxy and α-amino phosphonic as well as phosphinic acids esters and amides. The reduction of the P=O bond without concomitant scission of the ester and amide bonds is affected by use of BH3, a mild reducing agent, which affords the corresponding borane protected PIII phosphonite and phosphinite derivatives in one step. A mechanistic rationale is proposed for the role played by neighboring OH and NHR groups in facilitating the reduction, and for the observed chemo- and stereoselectivity. The reduction methodology described opens previously unavailable synthetic options in chemistry of α-functionalized phosphonic and phosphinic acids by offering a unique possibility for direct modifications of oxidation level of the P-center in these compounds.

P-H bond activation of primary phosphine-boranes: Access to α-hydroxy and α,α′-dihydroxyphosphine-borane adducts by uncatalyzed hydrophosphination of carbonyl derivatives

Primary P-phenyl and P-methyl phosphine-boranes 1 and 2 are prepared by complexation of the free phosphines with BH3 · SMe2. They are stable and can be purified by distillation. Under basic conditions, they lead selectively to secondary alkylphosphine-boranes and under neutral conditions to the corresponding mono- and bis-hydroxyphosphine-boranes 5 and 6. All these new compounds are purified by chromatography on silica gel. A competitive hydroboration induced by the decomplexation of BH3 is observed as a minor process. Conditions for the decomplexation of phosphine-borane adducts are presented.