Organoammonium salts composed of a Brønsted acid and an anilinothiourea promoted the Michael addition of β-keto esters and α,β-unsaturated aldehydes in the presence of primary amines to give functionalized 1,4-dihydropyridines enantioselectively. With the use of the different Brønsted acids such as DFA and HBF4 with the same bifunctional thiourea, both enantiomers of 4-substituted 1,4-dihydropyridine were synthesized from the same starting materials.
由布朗斯台德酸和
苯胺基
硫脲组成的有机
铵盐促进 β-
酮酯和 α,β-不饱和醛在
伯胺存在下发生迈克尔加成,从而对映选择性地生成官能化的 1,4-
二氢吡啶。使用不同的布朗斯台德酸(例如 DFA 和
HBF4)与相同的双官能
硫脲,从相同的起始原料合成了 4-取代 1,4-
二氢吡啶的两种对映体。