Department of Chemistry, School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany.
Org Biomol Chem. 2010 Sep 21;8(18):4085-9. doi: 10.1039/c0ob00049c. Epub 2010 Jul 12.
A pyridine based 1,2-diamine containing only one stereogenic center has been identified for fast aldol reactions (16-48 h). Using 2-5 mol% of (R)- or (S)-PicAm-2, cyclohexanone (3.3 equiv) readily undergoes aldol reactions with o-, m-, and p-substituted aromatic aldehyde partners (limiting reagent), including the poor electrophile 4-methylbenzaldehyde (95-99% ee). Furthermore, functionalized cyclic ketone substrates have been converted into four aldol products 9-12 using the lowest catalyst loading (5.0 mol%) to date with the highest yield and enantioselectivity.
一种仅含有一个手性中心的吡啶基 1,2-二胺已被确定用于快速醛醇反应(16-48 小时)。使用 2-5 摩尔%的(R)-或(S)-PicAm-2,环己酮(3.3 当量)很容易与邻、间、对取代的芳醛反应物(限制试剂)发生醛醇反应,包括较差的亲电试剂 4-甲基苯甲醛(95-99%ee)。此外,使用迄今为止最低的催化剂负载量(5.0 摩尔%),已将功能化的环状酮底物转化为四个醛醇产物 9-12,产率和对映选择性最高。