Generation Of Carbonyl Ylides Research Articles

ChemInform Abstract: ′On‐water′ Generation of Carbonyl Ylides from Diazoamides: Rhodium(II) Catalyzed Synthesis of Spiroindolo‐Oxiranes and ‐Dioxolanes with an Interesting Diastereoselectivity.

Abstract The ‘on-water’ generation of carbonyl ylide dipoles from diazoamides in the presence of rhodium(II) acetate dimer as the catalyst was demonstrated for the first time to synthesize spiroindolo-oxiranes and -dioxolanes. Unusual generation of carbonyl ylides with aromatic aldehydes having electron-withdrawing substituents and 1,3-dipolar cycloaddition reactions with aromatic aldehydes having electron-donating substituents were described in water with complete diastereoselectivity. This discovery provides an environmentally friendly way to generate carbonyl ylide dipoles and to synthesize substituted spiro-heterocycles in water with stereoselectivity, avoiding the use of toxic halogenated organic solvents.

‘On-water’ generation of carbonyl ylides from diazoamides: rhodium(II) catalyzed synthesis of spiroindolo-oxiranes and -dioxolanes with an interesting diastereoselectivity

The ‘on-water’ generation of carbonyl ylide dipoles from diazoamides in the presence of rhodium(II) acetate dimer as the catalyst was demonstrated for the first time to synthesize spiroindolo-oxiranes and -dioxolanes. Unusual generation of carbonyl ylides with aromatic aldehydes having electron-withdrawing substituents and 1,3-dipolar cycloaddition reactions with aromatic aldehydes having electron-donating substituents were described in water with complete diastereoselectivity. This discovery provides an environmentally friendly way to generate carbonyl ylide dipoles and to synthesize substituted spiro-heterocycles in water with stereoselectivity, avoiding the use of toxic halogenated organic solvents.

ChemInform Abstract: The Use of trans-2,3-Divinyl Epoxides as Precursors to Carbonyl Ylides.

trans-2,3-Divinyl epoxides have been found to be good substrates for the generation of carbonyl ylides in CCl4 and 145 °C. These ylides, to a limited extent, undergo isomerization to cis-2,3-divinyl epoxides, leading to the isolation of 4,5-dihydrooxepins. Of greater potential usefulness is the finding that these ylides can be efficiently trapped in an intermolecular sense by a dipolarophile, leading to dihydrofurans.

Azomethine, Carbonyl and Thiocarbonyl Ylides — Generation of Carbonyl Ylides by Intramolecular Reaction of Metal Carbenoids: An Approach to Tigliane and Daphnane Diterpenoids

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthetic Applications of Carbonyl Ylides Generated via the Tandem Cyclization Cycloaddition Reaction of Rhodium Carbenoids

AbstractThe author's chemical studies dealing with the generation of carbonyl ylides via the rhodium(II) induced cyclization of α‐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.