Tosylates, diphenylphosphates and bromides were employed to study the effect of the leaving group on the alkylation diastereoselectivity of the Schöllkopf chiral auxiliary 1 at aliphatic, benzylic, propargylic and allylic electrophilic centers. The diastereoselectivity generally follows the pattern: diphenylphosphate > tosylate > bromide. In terms of both diastereoselectivity and yield, each leaving
使用甲
苯磺酸盐,
磷酸二苯酯和
溴化物研究了离去基团对脂族,苄基,炔丙基和烯丙基亲电子中心的Schöllkopf手性助剂1烷基化非对映选择性的影响。非对映选择性通常遵循以下模式:
磷酸二苯酯>甲
苯磺酸盐>
溴化物。就非对映选择性和产率而言,每个离去基团具有不同的优势。