Nickel-Catalyzed Direct Cross-Coupling of Unactivated Aryl Fluorides with Aryl Bromides.

A nickel-catalyzed direct cross-coupling of unactivated aryl fluorides with aryl bromides is realized. The one-pot reaction, which avoids the use of preformed and sensitive organometallic reagents, proceeds effectively via C-F bond cleavage at room temperature in THF in the presence of the phosphine ligand and magnesium powder (with or without TMSCl) to produce the desired biaryls in modest to good yields.

Nickel-Catalyzed Direct Cross-Coupling of Aryl Thioether with Aryl Bromide.

A straightforward cross-coupling of aryl thioether with aryl bromide with the aid of nickel salt, magnesium, and lithium chloride in tetrahydrofuran at ambient temperature was accomplished. The one-pot reactions proceeded efficiently via C-S bond cleavage to produce the desired biaryls in modest to good yields, avoiding the use of pregenerated or commercial organometallic reagents.

Nickel-Catalyzed Direct Cross-Coupling of Aryl Fluorosulfates with Aryl Bromides.

A one-pot, direct cross-coupling of aryl fluorosulfate with aryl bromide, which is step-economical and avoids the use of a preprepared/commercial organometallic reagent, could be accomplished by performing the reaction in THF at room temperature in the presence of nickel catalyst, magnesium turnings, and lithium chloride, giving rise to the corresponding biaryls in moderate to good yields with reasonable functional group compatibility.

Nickel-Catalyzed Direct Cross-Coupling of Diaryl Sulfoxide with Aryl Bromide.

The direct cross-couplings of diaryl sulfoxides with aryl bromides via C-S bond cleavage could be readily accomplished using nickel(II) as the catalyst, 1,2-bis(diphenylphosphino)ethane (dppe) as the ligand, and magnesium turnings as the reducing metal in THF, leading to the corresponding biaryls in moderate to good yields. The reaction exhibited a broad substrate scope and could be applied to a gram-scale synthesis. The "one-pot" reaction, which avoids the utility of presynthesized and moisture-labile organometallic compounds, is operationally simple and step-economic.

Nickel-Catalyzed Direct Cross-Coupling of Aryl Sulfonium Salt with Aryl Bromide.

The direct cross-couplings of aryl sulfonium salts with aryl halides could be achieved by using nickel as a reaction catalyst. The reactions proceeded efficiently via C-S bond activation in the presence of magnesium turnings and lithium chloride in THF at ambient temperature to afford the corresponding biaryls in moderate to good yields, potentially serving as an attractive alternative to conventional cross-coupling reactions employing preprepared organometallic reagents.

Nickel-Catalyzed Diastereoselective Reductive Cross-Coupling of Disubstituted Cycloalkyl Iodides with Aryl Iodides.

A nickel-catalyzed direct reductive cross-coupling of disubstituted cycloalkyl iodides with aryl iodides was developed. The one-pot reaction, which is simple to operate, was capable of proceeding efficiently in a stereocontrolled manner to afford a variety of cross-coupled products with high diastereoselectivity and wide functional group tolerance.

Iron(0)-Mediated Reformatsky Reaction for the Synthesis of ß-Hydroxyl Carbonyl Compounds.

An efficient, economical, and practical Reformatsky reaction of α-halo carbonyl compounds with aldehydes/ketones by using cheap and commercial iron(0) powder as reaction mediator is developed. The reactions proceeded effectively in the presence of a catalytic amount of iodine (20 mol %) to afford the synthetically useful ß-hydroxyl carbonyl compounds in moderate to good yields.

Iron Catalysis for Modular Pyrimidine Synthesis through ß-Ammoniation/Cyclization of Saturated Carbonyl Compounds with Amidines.

An efficient method for the modular synthesis of various pyrimidine derivatives by means of the reactions of ketones, aldehydes, or esters with amidines in the presence of an in situ prepared recyclable iron(II)-complex was developed. This operationally simple reaction proceeded with broad functional group tolerance in a regioselective manner via a remarkable unactivated ß-C-H bond functionalization. Control experiments were performed to gain deep understanding of the mechanism, and the reactions are likely to proceed through a designed TEMPO complexation/enamine addition/transient α-occupation/ß-TEMPO elimination/cyclization sequence.