1,2-Diphenyl-1,2-ethylenediamine is an organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

 with the formula

Chemical formula

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 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

Reductive amination

Reductive amination is a form of amination that involves the conversion of a carbonyl group to an amine via an intermediate imine...

.

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

Tartaric acid

Tartaric acid is a white crystalline diprotic organic acid. It occurs naturally in many plants, particularly grapes, bananas, and tamarinds; is commonly combined with baking soda to function as a leavening agent in recipes, and is one of the main acids found in wine. It is added to other foods to...

 as the resolving agent

Optical resolution

Optical resolution describes the ability of an imaging system to resolve detail in the object that is being imaged.An imaging system may have many individual components including a lens and recording and display components...

. In methanol, the R,R enantiomer has an specific rotation

Specific rotation

In stereochemistry, the specific rotation of a chemical compound [α] is defined as the observed angle of optical rotation α when plane-polarized light is passed through a sample with a path length of 1 decimeter and a sample concentration of 1 gram per 1 millilitre. It is the main property used to...

 of [α]₂₃ +106±1°.

TsDPEN

N-tosyl

Tosyl

A tosyl group is CH3C6H4SO2. This group is usually derived from the compound 4-toluenesulfonyl chloride, CH3C6H4SO2Cl, which forms esters and amides of toluenesulfonic or tosylic acid...

ated derivative, TsDPENH, is a ligand precursor for catalysts for asymmetric transfer hydrogenation

Transfer hydrogenation

Transfer hydrogenation is the addition of hydrogen to a molecule from a source other than gaseous H2. It is applied in industry and in organic synthesis, in part because of the inconvenience and expense of using gaseous H2...

. For example (cymene)Ru(S,S-TsDPEN) catalyzes the hydrogenation

Hydrogenation

Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...

 of benzil

Benzil

Benzil is the organic compound with the formula 2, generally abbreviated 2. This yellow solid is one of the most common diketones...

 into R,R-hydrobenzoin

Benzoin

Benzoin is an organic compound with the formula PhCHCPh. It is a hydroxy ketone attached to two phenyl groups. It appears as off-white crystals, with a light camphor-like odor. Benzoin is synthesized from benzaldehyde in the benzoin condensation...

. In this reaction, formate

Formate

Formate or methanoate is the ion CHOO− or HCOO− . It is the simplest carboxylate anion. It is produced in large amounts in the hepatic mitochondria of embryonic cells and in cancer cells by the folate cycle Formate or methanoate is the ion CHOO− or HCOO− (formic acid minus one hydrogen ion). It...

 serves as the source of H₂:

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

This transformation is an example of desymmetrization

Desymmetrization

Desymmetrization in stereochemistry is the modification of a molecule that results in the loss of one or more symmetry elements. An important application involves the introduction of chirality. Formally, such conversion require the loss of an improper axis of rotation...

, the symmetric molecule benzil is converted to the dissymmetric product

Applications

DPEN and BINAP

BINAP

BINAP is an abbreviation for the organophosphorus compound 2,2'-bis-1,1'-binaphthyl. This chiral ligand is widely used in asymmetric synthesis. It consists of a pair of 2-diphenylphosphinonaphthyl groups linked at the 1 and 1´ positions. This C2-symmetric framework lacks stereogenic atom, but...

 are the key ingredients of Noyori's

Ryoji Noyori

is a Japanese chemist. He won the Nobel Prize in Chemistry in 2001. Noyori shared half of the prize with William S. Knowles for the study of chirally catalyzed hydrogenations; the second half of the Prize went to K. Barry Sharpless for his study in chirally catalyzed oxidation reactions...

 2nd Generation Ruthenium

Ruthenium

Ruthenium is a chemical element with symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most chemicals. The Russian scientist Karl Ernst Claus discovered the element...

 based chiral hydration catalyst, Ryōji Noyori earned the Nobel Prize

Nobel Prize

The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...

in 2001.