Reactions of diphenyldiazomethane in the presence of bis(acetylacetonato) copper (II). Modified diphenylmethylene reactions

Cyclopropanation Strategies in Recent Total Syntheses

“…The discovery that metal salts catalyze the decomposition of diazo compounds dates back to 1906, when Silberrad and Roy investigated the effect of copper dust on ethyl diazoacetate: “[...] When the diazoacetate is added to copper dust, no reaction appears to take place below 80 °C, but above that temperature the addition of the first drop of ester is accompanied by an explosion of sufficient violence to shatter the flask.[...]”. Another milestone was reached in the 1960s, when catalytic homogeneous diazo decomposition was enabled by soluble copper complexes. , A decade later, Teyssie and co-workers − discovered that Pd­(OAc) 2 and Rh 2 (OAc) 4 are suitable alternatives to copper salts.…”

Cyclopropanation

“…(acetylacetonate = acac) was the earliest homogeneous catalyst for catalytic cyclopropanation in organic solvent (12). Thereafter, other soluble catalysts have been developed (13)− (16).…”

Reactions of Organic Nitrogen Compounds with Carbenoids and Diarylketenes from Diazoalkanes and Diazocarbonyls

“…The successful use of bis(acetylacetonato)copper(II), Cu(acac) 2 in carbenoid reactions by the research groups of Nozaki [11] and Kobayashi [12], prompted us to use it in the ongoing reactions of diazoalkanes and diazoketones with nitrogen-containing organic compounds in our laboratory. Cu(acac) 2 -catalyzed reactions of diaryldiazoalkanes 1a-c and of 2-diazo-1,2-diphenylethanone 1d with primary amines 2, were reported to lead to the formation of N-substituted imines 3 (Scheme 2), the building blocks for many important heterocyclic compounds, in fair to good yields [13][14][15].…”