Competitive 3+2 and 2+2 cycloadditions of ester stabilized azaallyl anions to benzynes. Ring expansion of initial 3+2 products to isoquinolin-3-ones
作者:Helmi Hussain、Ebrahim Kianmehr、Tony Durst
DOI:10.1016/s0040-4039(01)00130-7
日期:2001.3
Reaction of the azaallyllithiums derived from imines of α-amino esters with benzynes results in the formation of 1,3-dihydroisoindoles and 4-hydroxyisoquinolines via 3+2 and 2+2 cycloadditions, respectively. The initially formed 1-carboethoxy-1,3-dihydroisoindoles rearrange under basic reaction conditions to form 3-(2H)-isoquinolinones.
We report geometry-dependent cyclizations of o-alkynylaryl ketoximes and nitrones catalyzed by goldcomplexes. (E)-Ketoximes undergo N-attack to give isoquinoline-N-oxides. In sharp contrast, (Z)-ketoximes undergo unprecedented O-nucleophilic attack, followed by a redoxcascade leading to a novel catalytic entry to isoindoles of diverse scope. The structure of an isoindole was unambiguously supported