Chiral Ca-, Sr-, and Ba-Catalyzed Asymmetric Direct-Type Aldol, Michael, Mannich, and Related Reactions
Chiral Ca-, Sr-, and Ba-Catalyzed Asymmetric Direct-Type Aldol, Michael, Mannich, and Related Reactions
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DOI：
10.1007/978-3-642-36270-5_7
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发表时间：
2013-08
影响因子：
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通讯作者：
T. Tsubogo;Y. Yamashita;S. Kobayashi
中科院分区：
文献类型：
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作者：
T. Tsubogo;Y. Yamashita;S. Kobayashi
摘要本章综述了近年来手性钙、锶、钡催化剂在不对称直接型Aldol、Michael、Mannich及相关反应中的研究进展。由于它们是自然界中丰富而普遍存在的元素，与重金属过渡金属相比，它们形成了相对安全和环境友好的化合物，因此非常有吸引力。然而，与过渡金属催化剂相比，它们在不对称合成中的应用受到了限制。它们的强Brnsted碱性和温和的Lewis酸性是很有前途的和有吸引力的特性，可以积极地影响它们的催化活性和手性修饰能力。结果表明，在高对映选择性催化剂上，几种不对称碳-碳键的形成及相关反应在手性钙、锶和钡催化剂上进行得很顺利。
AbstractRecent progress in asymmetric direct-type aldol, Michael, Mannich, and related reactions using chiral Ca, Sr, and Ba catalysts was summarized in this chapter. Ca, Sr, and Ba are very attractive, because they are abundant and ubiquitous elements found in nature, and form relatively safe and environmentally benign compounds compared with heavy transition metals. However, their use as catalysts in asymmetric synthesis has been limited compared with that of transition metal catalysts. Their strong Brønsted basicity and mild Lewis acidity are promising and attractive characteristics, and can influence their catalytic activity as well as their chiral modification capability in a positive manner. It was revealed that several catalytic asymmetric carbon–carbon bond-forming and related reactions proceeded smoothly in high enantioselectivites using the chiral Ca, Sr, and Ba catalysts.Graphical Abstract