SEGPHOS on:
[Wikipedia]
[Google]
[Amazon]
SEGPHOS is a 
chiral
Chirality () is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek language, Greek (''kheir''), "hand", a familiar chiral object.
An object or a system is ''chiral'' if it is dist ...
ligand
In coordination chemistry, a ligand is an ion or molecule with a functional group that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's el ...
developed by Takasago International Corporation that is used in asymmetric synthesis
Enantioselective synthesis, also called asymmetric synthesis, is a form of chemical synthesis. It is defined by IUPAC as "a chemical reaction (or reaction sequence) in which one or more new elements of chirality are formed in a substrate molecul ...
. It was developed after BINAP
BINAP (2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) is an organophosphorus compound. This Optical isomerism, chiral diphosphines, diphosphine ligand is widely used in chiral synthesis, asymmetric synthesis. It consists of a pair of 2-diphe ...
and was investigated since it has a narrower dihedral angle between the aromatic faces. This was predicted and then confirmed to increase the enantioselectivity and activity of metal complexes of SEGPHOS. After its commercialization, SEGPHOS and its substituted derivatives have been found to constitute a privileged ligand class for a variety of transition metal catalysts and chemical transformations beyond its original application in ruthenium-catalyzed enantioselective hydrogenation.
In addition to the parent ligand bearing phenyl groups on the phosphorus atoms, the bulkier derivatives DM-SEGPHOS and DTBM-SEGPHOS are also commercially available. In DM-SEGPHOS and DTBM-SEGPHOS, the phenyl groups of SEGPHOS are replaced by 3,5-dimethylphenyl and 3,5-di-''tert''-butyl-4-methoxyphenyl groups, respectively.
According to Takasago, as BINAP is likened to a butterfly, SEGPHOS is like a seagull that "flies higher and faster" than a butterfly.{{Cite web, url=https://www.takasago.com/en/news/2002/0607_0528.html, title=Takasago Received The Molecular Chirality Awards 2002, website=Takasago International Corporation, language=en, access-date=2019-08-14 Thus the ligand was named SE(A)G(ULL) + PHOS.
References