Generation of Arylated Quinones by Iron-Catalyzed Oxidative Arylation of Phenols: Formal Synthesis of Phellodonin, Sarcodonin ε, Leucomelone and Betulinan A

Nickel(0)-Catalyzed Decarbonylative Cross-Coupling of Aromatic Esters with Arylboronic Acids via Chelation Assistance

10-Arylbenzo[h]quinolines were synthesized by cross-coupling of ethyl benzo[h]quinoline-10-carboxylate with arylboronic acids via group-directed Ni(0) catalyzation. The catalytic system combining Ni(COD)₂ (10 mol %) with PCy₃ (20 mol %) and t-BuOK (3 equiv) was optimal for the above transformations. A series of arylboronic acids reacted with ethyl benzo[h]quinoline-10-carboxylates for the production of various substituted 10-phenyl[h]quinolines in moderate and good yields under optimized reaction conditions.

A visible-light-induced, metal-free bis-arylation of 2,5-dichlorobenzoquinone

A metal-free protocol for the direct bis-arylation of 2,5-dichlorobenzoquinone with aryldiazonium salts is reported. The reactive salts are generated in situ and converted to radicals through irradiation with visible light. Reaction products precipitate from the solvent, eliminating the need for purification and thus providing a novel green method for the synthesis of versatile bis-electrophiles.

Iron-catalyzed cross-coupling of arylboronic acids with unactivated N-heterocycles and quinones under microwave heating

The iron-catalyzed direct arylation of a variety of N-heteroarenes, quinones, and hydroquinones with arylboronic acids is investigated under microwave heating. The reaction proceeds at 70 °C under air using K2S2O8 as an oxidant and FeSO4 as a catalyst. Under microwave heating, reaction times decreased 14- to 115-fold. Reaction scope with N-heteroarenes and quinones is comparable with or slightly expanded when compared with previous reports, but the scope of arylboronic acid utility was slightly limited due to previously unobserved arylboronic acid hydroxydeboronation.

The Different Facets of Metal-Catalyzed C-H Functionalization Involving Quinone Compounds

Metal-catalysed C-H functionalization has emerged as a powerful platform for the derivatization of quinones, a class of compounds with wide-ranging applications. This review organises and discusses the evolution of this chemistry from early Fujiwara-Moritani reactions, through to modern directing-group assisted C-H functionalization processes, including C-H functionalization reactions directed by the quinone ring itself. Mechanistic details of these reactions are provided to afford insight into how the unique reactivity of quinoidal compounds has been leveraged in each example.

Organic synthesis with the most abundant transition metal–iron: from rust to multitasking catalysts

The promising aspects of iron in synthetic chemistry are being explored for three-four decades as a green and eco-friendly alternative to late transition metals. This present review unveils these rich iron-chemistry towards different transformations.

Regioselective Oxidative Arylation of Fluorophenols

A metal free and highly regioselective oxidative arylation reaction of fluorophenols is described. The relative position of the fluoride leaving group (i.e., ortho or para) controls the 1,2 or 1,4 nature of the arylated quinone product, lending versatility and generality to this oxidative, defluorinative, arylation concept.

Iron-catalysed enantioselective Suzuki–Miyaura coupling of racemic alkyl bromides

The first iron-catalyzed enantioselective Suzuki–Miyaura coupling reaction has been established by using electron-deficient P-chiral bisphosphine ligand (R,R)-QuinoxP*.

Metal-free, air-promoted, radical-mediated arylation of benzoquinone with phenylhydrazines

An efficient, economic, and air-promoted metal-free method for direct arylation of benzoquinone with phenylhydrazines was developed. This approach leads to the formation of corresponding [1,1′-biphenyl]-2,5-dione derivatives as biological and pharmaceutical materials of interest in good yields, under mild reaction conditions, and at ambient temperature.

Combination of organotrifluoroborates with photoredox catalysis marking a new phase in organic radical chemistry

Combination of organotrifluoroborates and visible-light-driven photoredox catalysis, both of which have attracted the attention of synthetic chemists, marks a new phase in the field of organic radical chemistry. We have developed photoredox-catalyzed radical reactions with organotrifluoroborates, which turn out to serve not only as a source of organic radicals but also as radical acceptors. The first part of this Perspective deals with the generation of organic radicals from organotrifluoroborates, and the latter part describes addition of the CF3 radical to alkenyltrifluoroborates. The good chemistry between organoborates and photoredox catalysis and its future will be discussed.

Redox-economical radical generation from organoborates and carboxylic acids by organic photoredox catalysis

Redox-economical radical reactions by organic photoredox catalysis.

The regioselective iodination of quinolines, quinolones, pyridones, pyridines and uracil

A radical based direct C–H iodination protocol for quinolines, quinolones, pyridones, pyridines, and uracil has been developed.