Otera's catalyst, named after Japanese chemist Junzo Otera, is an

organostannane compound Organotin compounds or stannanes are chemical compounds based on tin with hydrocarbon substituents. Organotin chemistry is part of the wider field of organometallic chemistry. The first organotin compound was diethyltin diiodide (), discovered by ...

which has been used as a

transesterification In organic chemistry, transesterification is the process of exchanging the organic group R″ of an ester with the organic group R' of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. The reaction can ...

catalyst. This isothioscyanate compound is a member of a family of organostannanes reported by Wada and coworkers, and elaborated upon by Otera and coworkers.

Preparation

This class of compounds may be prepared generally by the reaction of an organotin halide and oxide: : 2 R₂SnO + 2 R₂SnX₂ → (XR₂SnOSnR₂X)₂ In particular, the thiocyanate compound was prepared by the reaction of dibutyltin oxide with dibutyltin diisothiocyanate. Otherwise, this compound is not commercially available.

Applications

This thiocyanate compound can be used as a

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

. Although it is not well known, it has been used in a number of total syntheses. In this application, the reaction occurs via the displacement of the bridging isothiocyanate ligands with the incoming alcohol to form an alcohol-bridged active catalyst. Tin acts as the

Lewis acid A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...

, and gives the transesterified product.

References

{{reflist Organotin compounds Catalysts Thiocyanates Tin(IV) compounds