中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
四溴-2-磺基苯甲酸环酐 | 2,3,4,5-tetrabromo-6-sulfo-benzoic acid-anhydride | 68460-01-5 | C7Br4O4S | 499.757 |
Four catalysts based on new amides of chiral 1,2-diamines and 2-sulfobenzoic acid have been developed. The alkali-metal salts of these betaine-like amides are able to form imines with enones, which are activated by Lewis acid interaction for nucleophilic attack by 4-hydroxycoumarin. The addition of 4-hydroxycoumarin to enones gives ee’s up to 83% and almost quantitative yields in many cases. This novel type of catalysis provides an effective alternative to conventional primary amino catalysis were strong acid additives are essential components.