Reactions of Enamines with Dehydro Aromatic Compounds
Benzyne reacts with enamines through a combination of ene and 2 + 2 cycloadditions.One of the two possible ene reactions is greatly favored.The three-dimensional intermediate, 1,2-dehydro-o-carborane, eschews the 2 + 2 reaction in favor of the ene reaction that is less favored in the benzyne reactions.This preference is rationalized in terms of the different steric demands of the two intermediates.
Gingrich, Henry L.,Huang, Qiurong,Morales, Angel L.,Jones, Maitland