130818-07-4

Upstream product

• 149650-18-0 (2R,4S,5R)-2-(2-Methoxyphenyl)-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine 2-oxide 
• 54655-12-8 (2S,4S,5R)-3,4-Dimethyl-2,5-diphenyl-1,3,2-oxazaphospholidine 2-oxide 
• 16750-63-3 2-methoxyphenylmagnesium bromide 
• 211565-44-5 (-)-(2R,4R,5S)-2-phenyl-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine-2-oxide 
• 61739-41-1 (2R,4S,5R)-2-Chloro-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine 
• 299-42-3 ephedrine 
• 321-98-2 (1S,2R)-(+)-ephedrine 
• 77929-22-7 (R)-(-)-[O-methyl (o-anisyl)phenylphosphinate] 
• 644-97-3 Dichlorophenylphosphine 
• 87214-07-1 (2R,4S,5R)-2,3,4,5-tetrahydro-3,4-dimethyl-2,5-diphenyl-1,3,2-oxazaphosphole 
• 20663-35-8 (S_p)-(2-methoxyphenyl)methylphenylphosphine oxide 
• 35143-99-8 (R_p)-(2-methoxyphenyl)methylphenylphosphine oxide 
• 149650-19-1 (2R,4S,5R)-2-(2-Methoxyphenyl)-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine 

Downstream Products

• 77929-22-7 (R)-(-)-[O-methyl (o-anisyl)phenylphosphinate] 
• 87214-07-1 (2R,4S,5R)-2,3,4,5-tetrahydro-3,4-dimethyl-2,5-diphenyl-1,3,2-oxazaphosphole 
• 20663-35-8 (S_p)-(2-methoxyphenyl)methylphenylphosphine oxide 
• 130818-08-5 bis-(phenyl-2-methoxyphenyl)-pyrophosphinate 
• 130818-09-6 (S)-(2-methoxyphenyl)(4-methoxyphenyl)(phenyl)phosphine oxide 
• 130856-88-1 (R)-ethyl(2-methoxyphenyl)(phenyl)phosphane oxide 
• 35143-99-8 (R_p)-(2-methoxyphenyl)methylphenylphosphine oxide 

Relevant academic research and scientific papers

Preparation of Enantiomerically Pure Phosphine Oxides by Nucleophilic Displacement Chemistry using Oxazaphospholidines

The synthesis of enantiomerically pure triaryl- and diarylvinyl-phosphine oxides from PCl3 by three sequential nucleophilic displacements at phosphorus is demonstrated.A single diastereoisomer of the P-chlorooxazaphospholidine 4 is treated with an arylmagnesium halide to effect displacement of chloride.The major stereoisomer is formed with retention of configuration.After oxidation to the phosphine oxide with tert-butyl hydroperoxide, a second Grignard reaction leads to regiospecific and stereospecific P-O ring cleavage so that a second aryl group is introduced withretention of configuration.For the final step, the P-N bond is subjected to acid-catalysed methanolysis, previously shown to occur with inversion of configuration, followed by P-OMe displacement with a third arylmagnesium halide.The overall yield of triarylphosphine oxide is up to 29percent for the cited five steps.Simple methoxyaryl or 2-naphthyl residues are employed to demonstrate the methodology, which permits the multigram-scale preparation of this class of compound in >/= 94percent e.e.The stereochemical course of the nucleophilic displacements with arylmagnesium halides is consistent with a model in which the organomagnesium reagent is complexed to the oxo-group and attacks phosphorus cis-to it in a direction defined by both electronic and steric factors.

THE NUCLEOPHILIC DISPLACEMENT ROUTE TO HOMOCHIRAL ARYLPHOSPHINE OXIDES

The stereoisomerically pure oxazaphospholidine formed by reaction of (1R,2S)-ephedrine with PhPCl2 is oxidised by ButOOH to the corresponding P-oxide, shown to have R-stereochemistry at phosphorus by X-ray analysis.The product reacts regio- and stereospecifically with o-anisylmagnesium bromide to give the product formed by P-O fission with retention of configuration, which was also characterised by X-ray diffraction.The ephedrine residue was replaced by O-methyl under acid catalysis with inversion of configuration.Attempts to incorporate p-fluorophenyl using similar conditions led to isolation of the pyrophosphinate in low yield.The OMe residue in the methoxyphosphinate was readily displaced by aliphatic or aromatic Grignard reagents giving the corresponding phosphine oxides with inversion of configuration.This procedure constitutes a simple route to di- and triarylphosphine oxides in ca. 95percent e.e.; optical purities were estimated by NMR methods.