Development of the Formation of Enolate Controlled by Acid-base Bifunctional Organochalcogenide Catalysts

介绍了手性硫属化合物催化的不对称环丙烷化、环氧化和叠氮化反应。以(1S)-10-樟脑磺酸为原料，制备了含异龙脑或樟脑骨架的C2对称手性硫族化合物形成的新型Lewis酸/Bronsted碱催化剂。二外展-2-羟基-10-冰片基硒化物和LiH促进了苯那基溴与甲基乙烯酮的反应，得到所需的ee高达50%的反式环丙烷。在硒化物的催化下，苯那基溴与n -苄基-4-甲基苯磺酰胺反应生成了ee含量高达60%的顺式氮吡啶。虽然苯那基溴与芳香族醛反应生成氧环烷的收率高，对映选择性适中，但与脂肪族醛反应生成的环氧化物收率高，对映选择性差。

Asymmetric cyclopropanation, epoxidation and aziridination catalyzed by chiral chalcogenides are described. A novel Lewis acid/Bronsted base catalysts formed by a C2 symmetric chiral chalcogenide bearing isoborneol or camphor skeletons were readily prepared from (1S)-10-camphorsulfonic acid. Di-exo-2-hydroxy-10- bornyl selenide and LiH promoted the reaction of phenacyl bromide with methyl vinyl ketone to afford the desired trans cyclopropane with up to 50% ee. The reaction of phenacyl bromide with N-benzylidene-4-methylbenzenesulfonamide was also catalyzed by the selenide to produce the cis aziridine with up to 60% ee. Although the good yields and moderate enantioselectivities for oxirane formations were obtained from the reaction of phenacyl bromide with aromatic aldehydes, the reactions with aliphatic aldehydes afforded the desired epoxides in good yields and poor enantioselectivities.