Tuning Selectivity of Anionic Cyclizations: Competition between 5-Exo and 6-Endo-Dig Closures of Hydrazides of <i>o-</i>Acetylenyl Benzoic Acids and Based-Catalyzed Fragmentation/Recyclization of the Initial 5-Exo-Dig Products
作者:Sergey F. Vasilevsky、Tat’yana F. Mikhailovskaya、Victor I. Mamatyuk、Georgy E. Salnikov、Georgy A. Bogdanchikov、Mariappan Manoharan、Igor V. Alabugin
DOI:10.1021/jo901551g
日期:2009.11.6
nucleophile is controlled by the nature of alkyne substituents under the kinetic control conditions. In the presence of KOH, the initially formed 5-exo products undergo a new rearrangement that involves a ring-opening followed by recyclization to the formal 6-exo-products and rendered irreversible by a prototropic isomerization. DFT computations provide insight into the nature of factors controlling relative
Unexpected cyclization route for o-ethynylbenzoic acids hydrazides in the presence of base
作者:S. F. Vasilevsky、T. F. Mikhailovskaya
DOI:10.1007/s10593-009-0225-7
日期:2009.1
The reaction of o-ethynylbenzoic acids hydrazides with base has been studied. In the presence of a strong donor substituent (1,5-dimethylpyrazol-4-yl) it has been found that an unusual cyclization route occurs to give the corresponding benzopyridazinone instead of the expected isoindolinone.