NOBIN is an organic molecule used for asymmetric catalysis. NOBIN is related to BINOL and other analogs by both having a chiral axis and being a scaffold for certain chemical reactions. NOBIN is an excellent catalyst for the aldol reaction

Aldol reaction

The aldol reaction is a powerful means of forming carbon–carbon bonds in organic chemistry.Discovered independently by Charles-Adolphe Wurtz and Alexander Porfyrevich Borodin in 1872, the reaction combines two carbonyl compounds to form a new β-hydroxy carbonyl compound...

 producing reliable products, good yields, and excellent diastereoselectivity.

Though rotation around the bond joining the rings is limited by the hydrogen atoms, enantiomerically pure NOBIN may racemize

Racemization

In chemistry, racemization refers to the converting of an enantiomerically pure mixture into a mixture where more than one of the enantiomers are present...

 upon heating.

NOBIN is prepared by oxidative cross coupling of 2-naphthol

2-Naphthol

2-Naphthol, or β-naphthol, is a colorless crystalline solid with the formula C10H7OH. It is an isomer of 1-naphthol, differing by the location of the hydroxyl group on naphthalene. The naphthols are naphthalene homologues of phenol, with the hydroxyl group being more reactive than in the phenols....

 and 2-naphthylamine

2-Naphthylamine

2-Naphthylamine is an aromatic amine. It is used to make azo dyes. It is a known human carcinogen and has largely been replaced by less toxic compounds. 2-Naphthylamine is prepared by heating 2-naphthol with ammonium zinc chloride to 200-210 °C; or in the form of its acetyl derivative by heating...

. The oxidative source is metal ions in solution such as Fe²⁺ or a Cu²⁺ amine complex. Once racemic

Racemic

In chemistry, a racemic mixture, or racemate , is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule. The first known racemic mixture was "racemic acid", which Louis Pasteur found to be a mixture of the two enantiomeric isomers of tartaric acid.- Nomenclature :A...

 NOBIN is produced, it needs to be resolved

Chiral resolution

Chiral resolution in stereochemistry is a process for the separation of racemic compounds into their enantiomers. It is an important tool in the production of optically active drugs...

. One method for this is the use of camphorsulfonic acid

Camphorsulfonic acid

Camphorsulfonic acid, sometimes abbreviated CSA or 10-CSA is a organosulfur compound. Like typical sulfonic acids, it is a relatively strong acid that exists as a colourless solid that is soluble in organic solvents....

, in which the basic group of NOBIN is used to form a diastereomeric salt of one enantiomer

Enantiomer

In chemistry, an enantiomer is one of two stereoisomers that are mirror images of each other that are non-superposable , much as one's left and right hands are the same except for opposite orientation. It can be clearly understood if you try to place your hands one over the other without...

. The other enantiomer however will stay in solution.