化学
艾伦
重氮
卡宾
亲核细胞
分子内力
催化作用
功能群
药物化学
阳离子聚合
重氮乙酸乙酯
沃尔夫重排
光化学
作者
Kostiantyn O. Marichev,Huang Qiu,Austin C. Offield,Hadi D. Arman,Michael P. Doyle
标识
DOI:10.1021/acs.joc.6b01833
摘要
Phenylpropargyl diazoacetates exist in equilibrium with 1-phenyl-1,2-dien-1-yl diazoacetate - allenes that are rapidly formed at room temperature through 1,3-acyloxy migration catalyzed by gold(I) or gold(III) compounds, and these catalysts react solely with the π-donor rather than with the diazo group. The product allene of the aryldiazoacetates undergoes rearrangement that is not catalyzed by gold in which the terminal nitrogen of the diazo functional group adds to the central carbon of the allene, initiating a sequence of bond-forming reactions, resulting in the production of 1,5-dihydro-4H-pyrazol-4-ones in good yields. These 1,5-dihydro-4H-pyrazol-4-ones undergo intramolecular 1,3-acyl migration to form an equilibrium mixture and can quantitatively transfer the acyl group to an external nucleophile with formation of 4-hydroxypyrazoles. Reactions of phenylpropargyl phenyldiazoacetates catalyzed by cationic gold complexes are initiated at the diazo functional group to form a gold carbene whose subseque...
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