Otera's catalyst

Otera's catalyst, named after Japanese chemist Junzo Otera, is an organostannane compound which has been used as a transesterification catalyst. This isothioscyanate compound is a member of a family of organostannanes reported by Wada and coworkers,^[1] and elaborated upon by Otera and coworkers.^[2]

Otera's catalyst

Names
Other names Octabutyltetrathiocyanatostannoxane
Identifiers
CAS Number	95971-03-2 N
3D model (JSmol)	Interactive image
ChemSpider	17621074 N
PubChem CID	16689150
InChI InChI=1S/8C4H9.4CNS.2O.4Sn/c8*1-3-4-2;4*2-1-3;;;;;;/h8*1,3-4H2,2H3;;;;;;;;;;/q;;;;;;;;4*-1;;;4*+1 N Key: BCLBTLOINGPAIT-UHFFFAOYSA-N N
SMILES CCCC[Sn]1(N(=C=S)[Sn]2(O1[Sn]3(O2[Sn](N3=C=S)(CCCC)(CCCC)N=C=S)(CCCC)CCCC)(CCCC)CCCC)(CCCC)N=C=S
Properties
Chemical formula	C36H72N4O2S4Sn4
Molar mass	1196.08 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Preparation

This class of compounds may be prepared generally by the reaction of an organotin halide and oxide:^[3]

2 R₂SnO + 2 R₂SnX₂ → (XR₂SnOSnR₂X)₂

In particular, the thiocyanate compound was prepared by the reaction of dibutyltin oxide with dibutyltin diisothiocyanate.^[1] Otherwise, this compound is not commercially available.

Applications

This thiocyanate compound can be used as a transesterification catalyst.^[2] Although it is not well known, it has been used in a number of total syntheses.^[4][5]

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, and gives the transesterified product.^[2][3] The reaction must be performed in nonpolar solvents in order to colocate the acid and alcohol at the catalytic center.^[6]