Use of Acylhydrazones as Electrophiles in Mannich-Type Reactions, <i>β</i>-Lactam, Pyrazolidinone, and Pyrazolone Synthesis
作者:Shu Kobayashi、Takayuki Furuta、Kasumi Sugita、Hidekazu Oyamada
DOI:10.1055/s-1998-1843
日期:1998.9
In the presence of a catalytic amount of scandium triflate [Sc(OTf)3], 4-trifluoromethylbenzoylhydrazones reacted with silyl enolates to afford the corresponding adducts, β-N′-acylhydrazinocarbonyl compounds, in high yields. Reductive cleavage of the nitrogen-nitrogen bond of the hydrazino compounds was performed using Raney Ni under H2 atmosphere, to give β-aminocarbonyl compounds. The two-step process is regarded as a novel Mannich-type reaction using acylhydrazones as electrophiles. Moreover, the hydrazino compounds were also successfully converted to β-lactam, pyrazolidinone, and pyrazolone derivatives.
在催化量的三酸钪[Sc(OTf)3]存在下,4-三氟甲基苯甲酰肼与硅烯醇酯发生反应,得到相应的加合物δ-N′-酰肼羰基化合物,产量很高。在 H2 气氛下,使用 Raney Ni 对肼基化合物的氮-氮键进行还原裂解,得到δ-氨羰基化合物。这一两步反应被视为以酰基肼为亲电体的新型曼尼希式反应。此外,肼类化合物还成功地转化成了 δ-内酰胺、吡唑烷酮和吡唑酮衍生物。