摘要 : Hexasubstituted guanidinium moieties have been used as ionic liquid tags for organocatalyts for the first time. Such conjugates were obtained in the (S)-proline and (S)-pyrrolidine-2-ylmethyl series by alkylation reactions of pent... 展开 Hexasubstituted guanidinium moieties have been used as ionic liquid tags for organocatalyts for the first time. Such conjugates were obtained in the (S)-proline and (S)-pyrrolidine-2-ylmethyl series by alkylation reactions of pentasubstituted guanidines. The resulting guanidinium-tagged organocatalysts were applied to asymmetric direct aldol reactions providing high stereoselectivities and yields and good recyclability, and thus performed better than (S)-proline itself. 收起