Cycloadditions of nitrile oxides to compounds containing two-co-ordinate phosphorus or arsenic. Kinetic and thermodynamic regioselectivity
Abstract
Cycloaddition of p-chlorobenzonitrile oxide takes place only at the CP bond of the diazaphosphole (1) yielding one regioisomer (3), and at the CAs bond of the diaza-arsole (4) yielding the analogous regioisomer (5) as the kinetic product, the other regioisomer (6) being the thermodynamic product.