Copper/Manganese Cocatalyzed Oxidative Coupling of Vinylarenes with Ketones

Abstract

A novel copper/manganese cocatalyzed direct oxidative coupling of terminal vinylarenes with ketones via C(sp(3))-H bond functionalization following C-C bond formation has been developed using tert-butyl hydroperoxide as the radical initiator. Various ketones underwent a free-radical addition of terminal vinylarenes to give the corresponding 1,4-dicarbonyl products with excellent regioselectivity and efficiency through one step. A possible reaction mechanism has been proposed.

A Copper (II) Acetate Mediated Oxidative‐Coupling of Styrenes and Ethers Through an Unactivated C(sp3)−H Bond Functionalization

“…Our methods were achieved by metal catalysts and simple operations which make the reaction easy to control. Several typical substrates namely alcohol, ketone and nitrile were reported. Herein, we would like to report a Cu(OAc) 2 catalyzed direct oxidative coupling of styrenes with ethers via C( sp 3 )−H bond functionalization (Scheme ).…”

Nonclassical Mechanism in the Cyclodehydration of Diols Catalyzed by a Bifunctional Iridium Complex

“…The combined organic phases were dried with MgSO 4 , filtered, and concentrated under vacuum. The residue was purified by column chromatography (petroleum ether/ethyl acetate, 9:1, v/v) to give the desired diketone 5 …”

“…The residue was purified by column chromatography (petroleum ether/ethyl acetate, 9:1, v/v) to give the desired diketone 5. [20] Synthetic route B:I nas ealed glass tube equipped with as tirrer bar,t he corresponding benzaldehyde precursor 9 (0.09 mol), triethylamine (19.5 mL, 0.14 mol), methyl vinyl ketone (10,0 .09 mol), and 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide (11,3.53 g, 0.014 mol) were mixed together (see the Supporting Information). The flask was heated in the cavity of am icrowave reactor for 15 min (150 W, internal temperature = 70 8C, internal pressure = 60 psi).…”

Recent Advances in Radical Difunctionalization of Simple Alkenes

“…A wider range of substrates and good yields were obtained in our case. Using the same strategy, we then investigated Cu/Mn‐cocatalyzed oxidative coupling of styrenes with ketones to construct 1,4‐dicarbonyl compounds 30 [Scheme , (2)] . In these reactions, Cu(OTf) 2 and MnCl 2 · H 2 O exhibited good synergism to improve the reaction efficiency with TBHP as oxidant and DBU as base.…”