Divergence of Carbonyl Ylide Reactions as a Function of Diazocarbonyl Compound and Aldehyde Substituent:  Dioxolanes, Dioxolenes, and Epoxides

• Published in: Journal of organic chemistry 2004-08, Vol.69 (16), p.5269-5274
• Main Authors: Russell, Albert E, Brekan, Jonathan, Gronenberg, Luisa, Doyle, Michael P
• Format: Article
• Language: English
• Subjects: Benzaldehydes - chemistry; Catalysis; Chemistry; Cyclization; Diazonium Compounds - chemistry; Epoxy Compounds - chemistry; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with o, s, se, te hetero atom and condensed derivatives; Indicators and Reagents; Models, Molecular; Molecular Structure; Organic chemistry; Preparations and properties; Rhodium - chemistry
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo049403y

The products from dirhodium(II) acetate-catalyzed reactions between diazocarbonyl compounds and a series of benzaldehydes demonstrate the extent of competition between intramolecular and intermolecular trapping of carbonyl ylide intermediates and the electronic effects that govern these transformations. With dimethyl diazomalonate, competition exists between dioxolane and epoxide formation so that with p-anisaldehyde only epoxide formation is observed and with p-nitrobenzaldehyde only 1,3-dioxolane products are formed. With methyl diazoacetoacetate, intramolecular trapping of the intermediate carbonyl ylide results in the sole production of dioxolenes. However, the vinyldiazoacetate analogue of methyl diazoacetoacetate, as its tert-butyldimethlsilyloxy derivative, only produces epoxides in its reactions with substituted benzaldehydes.