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
SMILES N[C@@H](c1ccccc1)[C@H](c2ccccc2)N
InChI InChI=1S/C14H16N2/c15-13(11-7-3-1-4-8-11)14(16)12-9-5-2-6-10-12/h1-10,13-14H,15-16H2/t13-,14-/m0/s1 Y Key: PONXTPCRRASWKW-KBPBESRZSA-N Y InChI=1/C14H16N2/c15-13(11-7-3-1-4-8-11)14(16)12-9-5-2-6-10-12/h1-10,13-14H,15-16H2/t13-,14-/m0/s1 Key: PONXTPCRRASWKW-KBPBESRZBK
Properties
Molecular formula	C14H16N2
Molar mass	212.29 g/mol
Appearance	White crystals
Melting point	79-83 °C
Solubility in water	Slightly
Related compounds
Y (verify) (what is: Y/N?) 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]

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