Studies on Remote Asymmetric Induction Using Chiral Pyrrolyl Sulfoxides and its Catalytic Reactions

1. 2-（对甲苯亚磺酰基）吡咯基烯酮（E-肉桂酰基、E-己烯酰基和巴豆酰基）与环戊二烯在镧系元素三氟甲磺酸盐和三氯化铝等刘易斯酸存在下，顺利地进行Diels-Alder反应，得到相应的单一异构体的内加成物（非对映异构体过量>90%）.用铜酸（二）烷基酯与手性2-（对甲苯亚磺酰基）吡咯基（E）-肉桂酰基酮和巴豆酰基酮进行共轭加成反应，得到相应的两种加成产物，非对映异构体过量高达30%。另一方面，手性2-（对甲苯亚磺酰基）吡咯基（E）-肉桂酰酮与（二）芳基铜酸酯如邻甲苯基-、对甲苯基-和（1-萘基）-铜酸酯的加成反应得到了相应的加成产物，其R构型的非对映异构体过量>90%。与巴豆酰基衍生物类似的反应得到了具有中等至优异非对映选择性的加成产物，主要产物在新形成的不对称碳中心的绝对立体化学通过X-射线分析或通过醇解转化为已知化合物来确定。特别是对于这两个加成反应，助剂（即亚磺酰基吡咯）通过产物的醇解回收，而没有任何光学纯度的损失。

1. Diels-Alder reaction of 2-(p-tolylsulfinyl) pyrrolyl enones {(E)-cinnamoyl, (E)-pent-2-enoyl and crotonoyl} with cyclopentadiene proceeded smoothly to give the corresponding endo adducts as a single isomer (>90% diastereoisomeric excesses) in the presence of a Lewis acid such a lanthanoid triflate and aluminum (III) chloride.2. Conjugate addition reaction to chiral 2-(p-tolylsulfinyl) pyrrolyl (E)-cinnamoyl and crotonoyl ketones using (di) alkyl cuprates afforded the corresponding two addition products with up to 30% diastereoisomeric excesses. On the other hand, addition reactions to chiral 2-(p-tolylsulfinyl) pyrrolyl (E)-cinnamoyl ketones with (di) aryl cuprates such as o-tolyl-, p-tolyl-, and (1-naphthyl)-cuprates afforded the corresponding addition products which have R configuration with >90% diastereoisomeric excesses. Similar reactions to the crotonoyl derivative by arylcuprates afforded the addition products with modest to excellent diastereoselectivities.The absolute stereochemistry at newly formed asymmetric carbon center of the major products was determined by X-ray analysis or by transformation into the known compounds by alcoholysis. In particular for these two addition reactions, the auxiliary (i.e.the sulfinyl pyrrole) was recovered by alcoholysis of the products without any loss of optical purity.