Diphenylethylenediamine

Diphenylethylenediamine
IUPAC name

1,2-Diphenyl-1,2-diaminoethane
Other names

DPEN
Identifiers
CAS number 35132-20-8
PubChem 6931238
ChemSpider 5305408 Y
ChEMBL CHEMBL467308 Y
Jmol-3D images Image 1
Properties
Molecular formula C14H16N2
Molar mass 212.29 g/mol
Appearance White crystals
Melting point

79-83 °C
Solubility in water Slightly
Related compounds
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

1,2-Diphenyl-1,2-ethylenediamine is an organic compound with the formula H2NCHPhCHPhNH2, where Ph is C6H5, phenyl. This diamine is a precursor to a ligand for certain homogeneous hydrogenation catalysts. It can be prepared from benzil by reductive amination.[1]

Contents

Optical resolution

DPEN can be obtained as both the chiral and meso diastereomers, depending on the relative stereochemistry of the two CHPhNH2 subunits. The chiral diastereomer, which is of greater value, can be resolved into the R,R- and S,S- enantiomers using tartaric acid as the resolving agent. In methanol, the R,R enantiomer has an specific rotation of [α]23 +106±1°.

TsDPEN

N-tosylated derivative, TsDPENH, is a ligand precursor for catalysts for asymmetric transfer hydrogenation. For example (cymene)Ru(S,S-TsDPEN) catalyzes the hydrogenation of benzil into R,R-hydrobenzoin. In this reaction, formate serves as the source of H2:[2]

PhC(O)C(O)Ph + 2 H2 → PhCH(OH)CH(OH)Ph

This transformation is an example of desymmetrization, the symmetric molecule benzil is converted to the dissymmetric product

Applications

DPEN and BINAP are the key ingredients of Noyori's 2nd Generation Ruthenium based chiral hydration catalyst, Ryōji Noyori earned the Nobel Prize in 2001.

References

  1. ^ S. Pikul, E. J. Corey (1998), "(1R,2R)-(+)- and (1S,2S)-(-)- 1,2-Diphenyl-1,2-Ethylenediamine", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV9P0387 ; Coll. Vol. 9: 387 
  2. ^ Takao Ikariya, Shohei Hashiguchi, Kunihiko Murata, and Ryōji Noyori (2005), "Preparation of Optically Active (R,R)-Hydrobenzoin from Benzoin or Benzil", Org. Synth.: 10, http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=v82p0010