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