Palladium-catalyzed cyclization reactions of 2-vinylthiiranes with heterocumulenes. Regioselective and enantioselective formation of thiazolidine, oxathiolane, and dithiolane derivatives.
The first palladium-catalyzed ring-expansion reaction of 2-vinylthiiranes with heterocumulenes to form sulfur-containing five-membered-ring heterocycles is described. This regioselective reaction requires 5 mol % of Pd(2)(dba)(3).CHCl(3) and 10 mol % of bidendate phosphine ligand (dppp, BINAP), at 50-80 degrees C, in THF. The reaction of 2-vinylthiiranes with carbodiimides, isocyanates, and ketenimines affords 1,3-thiazolidine derivatives, whereas the reaction with diphenylketene or isothiocyanates results in the formation of 1,3-oxathiolane or 1,3-dithiolane compounds in good to excellent isolated yields and in up to 78% ee.
Larksarp
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Centre for Catalysis Research and Innovation, Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, Canada K1N 6N5.
Sellier
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Alper
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D002384:Catalysis; D010165:Palladium; D013440:Sulfides / Q000737:chemistry*; D013457:Sulfur Compounds / Q000138:chemical synthesis; D013844:Thiazoles / Q000138:chemical synthesis
D013440:Sulfides; D013457:Sulfur Compounds; D013844:Thiazoles; D010165:Palladium; C013523:ethylene sulfide