Reactions of copper(II) β-diketonates under free radical conditions. Preparation of highly congested β-diketones.

Lanthanide-Catalyzed Oxidative С–O Coupling of 1,3-Dicarbonyl Compounds with Diacyl Peroxides

“…11 In a number of earlier studies, 2acyloxy-1,3-dicarbonyl compounds were synthesized using hypervalent iodine compounds, 12 manganese(III) acetate, 13 lead(IV) acetate, 14 iron(III) salts, 15 and the copper-catalyzed formal O-H insertion of 2-diazo-1,3-dicarbonyl compounds to carboxylic acids. 16 To perform the benzoyloxylation with the less reactive benzoyl peroxide as oxidant, the dicarbonyl substrates were transformed into enamines, 17 copper complexes, 18 and sodium enolates. 19 From the afore-mentioned published facts it should be evident that the sluggishly reactive diacyl peroxides, especially the acyclic benzoyl peroxide, require activation with an appropriate catalysts to effect the C-O cross-coupling with the 1,3-dicarbonyl substrate.…”

Selective Mono‐allylation of 1,3‐Diketones and Their Use in the Synthesis of 3‐Allyl Chromones and Benzannulated 6,5‐Bicyclic Ketals

“…In addition, C‐ vs. O‐alkylation, retro‐Claisen reactions, and the instability of alkylating agents to basic media, are all issues encountered and can give rise to a mixture of products . The use of beta‐diketones in the form of their cobalt(II) complexes has extended the scope of their C‐alkylations and allylations . Oxidative additions of 1,3‐dicarbonyl compounds to alkenes can be initiated using one‐electron oxidizing agents such as ceric ammonium nitrate (CAN) and manganese (III) acetate, however these reactions often result in the production of dihydrofurans or nitrate esters.…”

“…[1] The use of beta-diketones in the form of their cobalt(II) complexes has extended the scope of their C-alkylations and allylations. [2] Oxidativea dditions of 1,3-dicarbonyl compounds to alkenes can be initiated using one-electrono xidizing agents such as ceric ammonium nitrate (CAN) [3] and manganese (III) acetate, [4] howevert hese reactions often result in the production of dihydrofurans or nitrate esters. Allylations can be further improved by using silicon as ab eta-carboradical stabilizer, [5] however this limits the user to specific reagents.…”

Green and Scalable Palladium‐on‐Carbon‐Catalyzed Tsuji–Trost Coupling Reaction Using an Efficient and Continuous Flow System

“…3‐Allyl‐3‐methylpentane‐2,4‐dione (4c): Prepared according to Method A, using 2 mmol of the allylic acetate and 1 mmol of nucleophile, as a yellow oil; yield: 68 mg (44 %). Prepared according to Method B, using 2 mmol of the allylic acetate and 1 mmol of nucleophile, as a yellow oil; yield: 369 mg (48 %).…”