A 4-Hydroxypyrrolidine-Catalyzed Mannich Reaction of Aldehydes: Control of<i>anti-</i>Selectivity by Hydrogen Bonding Assisted by Brønsted Acids
作者:Enrique Gómez-Bengoa、Miguel Maestro、Antonia Mielgo、Itziar Otazo、Claudio Palomo、Irene Velilla
DOI:10.1002/chem.200903537
日期:2010.5.10
anti‐selective Mannich reaction of aldehydes with N‐sulfonyl imines has been developed by using a 4‐hydroxypyrrolidine in combination with an external Brønsted acid. The catalyst design is based on three elements: the α‐substituent of the pyrrolidine, the 4‐hydroxy group, and the Brønsted acid, the combination of which is essential for high chemical and stereochemical efficiency. The reaction works with
通过将4-羟基吡咯烷与外部布朗斯台德酸结合使用,开发了醛与N-磺酰基亚胺的抗选择性曼尼希反应。催化剂的设计基于三个要素:吡咯烷的α-取代基,4-羟基和布朗斯台德酸,两者的结合对于提高化学和立体化学效率至关重要。该反应可与芳香醛衍生的亚胺一起使用,在以前报道的基于烯胺的抗曼尼希反应中很少使用。此外,这两种Ñ甲苯磺酰和Ñ -nosyl亚胺可以成功地使用和曼尼期加合物可以容易地还原或氧化,并经过Ñ对相应的β-氨基酸和β-氨基醇进行脱保护可以得到良好的收率。结果还表明,这种三元催化体系在其他基于烯胺的反应中可能是可行的。