Benzene → 2-Phenylpropanal

HRID 376943Notes

Reaction equation

HRID 376943 reaction equation
[CH2:1]=[CH:2][C:3]1C=CC=CC=1.[C]=[O:10].[H][H].[CH:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1>C/C(/O)=C/C(C)=O.[C-]#[O+].[C-]#[O+].[Rh]>[CH3:1][CH:2]([C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)[CH:3]=[O:10].[CH:3](=[O:10])[CH2:2][CH2:1][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

7

Reactant 4

HCID 241BenzeneHCID 7501StyreneHCID 178418361HCID 178418361, compoundHCID 178418416HCID 178418416, compound

Product 2

HCID 71462-PhenylpropanalHCID 7707Benzenepropanal

Reagents, catalysts & solvents 1

HCID 5377512Rhodium, dicarbonyl(2,4-pentanedionato)-Catalyst

Procedure

Into a 50-ml stainless-steel autoclave were introduced 15 mg of the rhodium complex synthesized in Example 3 (containing 0.0031 mmol of rhodium), 0.71 ml (6.20 mmol) of styrene, and 0.35 ml of benzene. The contents were stirred at 60° C. for 40 hours in an atmosphere of 50-atm carbon monoxide and 50-atm hydrogen. A small portion of the reaction mixture was taken out and filtered to remove the catalyst. This reaction mixture was analyzed by 1H NMR spectrometry to determine the conversion. As a result, the conversion was found to be 97%. The proportion of the α-methylphenylacetaldehyde to dihydrocinnamaldehyde yielded (position selectivity) was 94:6. These reaction products were converted to carboxylic acids by Jones oxidation, and then analyzed by GC using a chiral column (Chrompack Cp-Cyclodex β-236M) to determine the enantiomer excess. As a result, the enantiomer excess was found to be 82% ee.

Workup

  1. filtrationfiltered
  2. customto remove the catalyst

Sources & evidence

ORD record
ord-ac978937370f4bedbbecb4498ce729b1
Source dataset
uspto-grants-2000_02
Patent number
US06022936

Reaction notes

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