81238-80-4

Upstream product

• 1517-69-7 (R)-1-phenylethanol 
• 814-49-3 diethyl chlorophosphate 
• 1445-91-6 (S)-1-phenylethanol 
• 98-85-1 1-Phenylethanol 
• 1021-45-0 phosphoric acid diethyl ester-(1-phenyl-vinyl ester) 
• 104549-95-3 (S)-(-)-(1-Hydroxy-1-phenylethyl)phosphonsaeurediethylester 

Downstream Products

• 104549-95-3 (S)-(-)-(1-Hydroxy-1-phenylethyl)phosphonsaeurediethylester 

Relevant academic research and scientific papers

Substitution of Secondary Benzylic Phosphates with Diarylmethyl Anions

Substitution of diethyl and diphenyl benzylic phosphates, Alk-CH(Ar1)OP(O)(OR)2 (R = Et, Ph; Alk = Me, Et, i-Pr; Ar1 = aryl), with the anions derived from Ar2CH2 (Ph2CH2,9H-xanthene and fluorene) and n-BuLi at –15 °C was studied. For phosphates with Me as an Alk, diethyl phosphates produced Me-CH(Ar1)CH(Ar2)2 (Ar1 = 4-halo-, 4-CN, 4-Me-, 2-Me, 2-Br-, 3-MeO-phenyl and 2-naphthyl). However, an unwanted substitution at the Et group competed with phosphates of Alk = Et- and i-Pr. Fortunately, the corresponding diphenyl phosphates cleanly underwent the desired substitution. Two enantioenriched phosphates, MeCH(Ph)OP(O)(OEt)2 and EtCH(Ph)OP(O)(OPh)2, proceeded with complete inversion of the stereochemistry.

Examining the origin of selectivity in the reaction of racemic alcohols with chiral N-phosphoryl oxazolidinones

A range of known and novel N-phosphoryl oxazolidinones and imidazolidinones were prepared and screened in the kinetic resolution of a range of racemic magnesium chloroalkoxides. Models are proposed to account for the enantioselectivity achieved based on a combination of chiral relay effects, generation of transient stereochemistry and the structure of the intermediate magnesium alkoxide.

Asymmetric hydrogenation of enol phosphinates by iridium catalysts having N,P ligands

Enol phosphinates, which are structural analogues of enol acetates, have for the first time been employed as substrates for Ir-catalyzed asymmetric hydrogenation. A number of enol phosphinates have been synthesized and reduced successfully with up to and above 99% ee.

Stereochemical consequences of the use of chiral N-phosphoryl oxazolidinones in the attempted kinetic resolution of bromomagnesium alkoxides

A number of chiral N-phosphoryl oxazolidinones have been prepared and evaluated as asymmetric phosphoryl transfer agents with the magnesium alkoxide of 1-phenyl ethanol. The reaction proceeded with little stereoselection, which was shown to be a consequence of the reaction mechanism that occurs with inversion of configuration at phosphorus consistent with in-line attack opposite the leaving group.

Phosphonate-Phosphate- and Phosphate-Phosphonate-Rearrangement and Its Application, Part II: Stereochemistry of Phosphonate-Phosphate-Rearrangement at Carbon as Exemplified by the Isomerisation of (R)-(+)- and (S)-(-)-(1-Hydroxy-1-phenylethyl)phosphonic Acid Diethylester

The phosphonate-phosphate-rearrangement of (R)-(+)- and (S)-(-)-6 was investigated at room temperature in various organic solvents and mixtures of organic solvent and of up to 7percent of water , using potassium t-butoxide, potassium hydroxide, and DBU as bases.The rearrangement is shown to occur with retention of configuration at carbon.The highest enantiomeric excess (10.7percent) for phosphate 8 was observed using a mixture of DMSO and water (100:7) containing DBU as base.Under these conditions the cleavage of phosphonate 6 into acetophenone and phosphite predominates and the yield of phosphate 8 is only 7.7percent. - Keywords.Stereochemistry; Phosphonate-phosphate-rearrangement; DMSO; DBU.

Stereochemistry of the Phosphate-Phosphonate Rearrangement

The enantiomerically pure 1-phenylethanols (R)-(+)-5 and (S)-(-)-5 were transformed into the diethyl phpsphates (R)-(+)-6 and (S)-(-)-6, which were subjected a phosphate-phosphonate rearrangement to give the 1-hydroxyphosphonates (-)-7 and (+)-7, respecti