Department of Chemistry, School of Science, The University of Tokyo, Tokyo, Japan.
Chem Asian J. 2013 May;8(5):872-6. doi: 10.1002/asia.201300102. Epub 2013 Mar 11.
Out of the pybox: We have developed a novel chiral calcium iodide catalyst from CaI2 and a pybox that is stable under moisture and oxygen. This catalyst was applied to catalytic asymmetric Mannich-type reactions of malonates with both N-Boc-protected aromatic and aliphatic imines, and resulted in moderate to high yields with high enantioselectivities. To the best of our knowledge, this is the first example of highly enantioselective metal-catalyzed asymmetric Mannich-type reactions of malonates with N-Boc-protected aliphatic imines. The Mannich adduct was successfully converted into the α-hydroxy β-amino acid derivative. We have also shown the unique structure of the chiral Ca complexes with malonates.
从 Pybox 中取出：我们从 CaI2 和 Pybox 中开发出了一种新型的手性碘化钙催化剂，该催化剂在潮湿和氧气条件下稳定。该催化剂应用于丙二酸盐与 N-Boc 保护的芳族和脂肪族亚胺的催化不对称曼尼希型反应，得到了中等至高产率和高对映选择性。据我们所知，这是首例高度对映选择性的金属催化丙二酸盐与 N-Boc 保护的脂肪族亚胺的曼尼希型反应。曼尼希加成物成功地转化为α-羟基β-氨基酸衍生物。我们还展示了手性 Ca 配合物与丙二酸盐的独特结构。
