SYNTHETIC APPLICATIONS OF CARBONYL YLIDES GENERATED VIA THE TANDEM CYCLIZATION CYCLOADDITION REACTION OF RHODIUM CARBENOIDS

The author's chemical studies dealing with the generation of carbonyl ylides via the rhodium(II) induced cyclization of alpha-diazo alkanediones are summarized. Dipole formation occurs by reaction of a transient rhodium carbenoid intermediate with a neighboring carbonyl group. These cyclizations are performed under extremely mild conditions, typically at room temperature in a neutral organic solvent. Since these cycloadditions involve carbonyl ylides, the resulting products are oxabicycles of varying ring size. When the dipolarophile is intramolecularly tethered to the dipole, the subsequent cycloaddition affords complex oxapolycyclic systems with three (or more) component rings.