A bimetallic aluminum(salen) complex for the synthesis of 1,3-oxathiolane-2-thiones and 1,3-dithiolane-2-thiones.
The combined use of the bimetallic aluminum(salen) complex [Al(salen)](2)O and tetrabutylammonium bromide (or tributylamine) is found to catalyze the reaction between epoxides and carbon disulfide. In most cases, at 50 °C, the reaction produces 1,3-oxathiolane-2-thiones, while at 90 °C, 1,3-dithiolane-2-thiones are the main product. The structure and stereochemistry of three of the 1,3-dithiolane-2-thiones is unambiguously determined by X-ray crystallographic analysis, and this is used to correct errors in the literature concerning the synthesis of cyclic di- and trithiocarbonates. The kinetics of 1,3-oxathiolane-2-thione synthesis are determined, and the resulting rate equation, along with a stereochemical analysis of the reaction and catalyst modification studies, is used to determine a mechanism for the synthesis of 1,3-oxathiolane-2-thiones which contrasts with the mechanism previously determined for cyclic carbonate synthesis using the same bimetallic aluminum(salen) complex.
Clegg
William
W
School of Chemistry and University Research Centre in Catalysis and Intensified Processing, Bedson Building, University of Newcastle, Newcastle upon Tyne NE1 7RU, UK.
Harrington
Ross W
RW
North
Michael
M
Villuendas
Pedro
P
D000535:Aluminum / Q000737:chemistry*; D002246:Carbon Disulfide / Q000737:chemistry; D002384:Catalysis; D018360:Crystallography, X-Ray; D004852:Epoxy Compounds / Q000737:chemistry; D005029:Ethylenediamines / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D013871:Thiones / Q000138:chemical synthesis* / Q000737:chemistry
D004852:Epoxy Compounds; D005029:Ethylenediamines; D009942:Organometallic Compounds; D013871:Thiones; C011452:disalicylaldehyde ethylenediamine; D000535:Aluminum; D002246:Carbon Disulfide