Enantioselective reaction of α-lithiated thiazolidines as new chiral formyl anion equivalents

Article abstract of DOI:10.1016/j.tetasy.2004.08.010

The reaction of lithiated N-Boc-thiazolidine and N-Boc-benzothiazolidine with benzophenone in the presence of (-)-sparteine afforded the products with up to 97% ee and 93% ee, respectively. The reaction with various aromatic and aliphatic aldehydes also afforded the products with high enantioselectivity and moderate diastereoselectivity. Each diastereomer could be converted to optically active diols. Consequently, lithiated N-Boc-thiazolidine and N-Boc-benzothiazolidine serve as chiral formyl anion equivalents. The reaction was confirmed to proceed through a dynamic thermodynamic resolution pathway.