A general rhodium-catalyzed cross-coupling reaction of thiols with aryl iodides

The general procedure for the rhodium-catalyzed cross-coupling of thiols with aryl iodides is described. The catalytic system consists of 5 mol % of [RhCl(cod)]₂ and 10 mol % of PPh₃ as a ligand. A variety of aryl iodides reacted with thiols, giving aryl thioethers in good to excellent yields. It is important to note that the deactivated aryl iodides such as 4-iodoanisole is worked smoothly to provide the corresponding aryl thioethers in excellent yields. Functional groups such as free-amines, chloro, are all tolerated under the employed reaction conditions.     

Palladium catalyzed atom-efficient cross-coupling reactions of triarylbismuths with aryl iodides and aryl triflates

The atom-efficient cross-coupling of triarylbismuths with aryl iodides or aryl triflates using catalytic Pd(OAc)₂/PPh₃ and K₃PO₄ as base in DMF at 90 °C to afford the corresponding functionalized biaryls in high yields is reported.     

Efficient ligand-free nickel-catalyzed C-S cross-coupling of thiols with aryl iodides

NiCl₂·6H₂O efficiently catalyzes the C-S bond formation by the cross-coupling of aryl iodides with thiols in tetrabutylammonium bromide (TBAB) in excellent yield. The reaction functions in air and the NiLn-TBAB can be recovered and recycled without the loss of activity.     

Triallyl(aryl)silanes serve as a convenient agent for silicon-based cross-coupling reaction of aryl halides

Triallyl(aryl)silanes, stable and easily accessible arylsilanes, were found to react with aryl bromides in the presence of a palladium catalyst (PdCl₂-PCy₃) and tetrabutylammonium fluoride (TBAF) in good yields. The scope of the reaction is broad, and a wide variety of functional groups are tolerant. Allyl groups on Si are readily cleaved upon treatment with TBAF to form fluorosilanes, silanepolyols, siloxanes and/or their mixed forms, which might be responsible for high efficiency of the reaction.     

Palladium-catalyzed aminocarbonylation of aryl iodides using aqueous ammonia

Aminocarbonylation of aromatic iodides using aqueous ammonia in toluene has been developed. Various primary aromatic amides have been efficiently synthesized in good to excellent yields in the presence of catalytic quantities of Pd(OAc)₂/CYTOP®292. The usage of aqueous ammonia avoids the handling of two gases in the reaction.     

Copper-catalyzed N-arylation of sulfonamides with aryl bromides and iodides using microwave heating

The copper-catalyzed N-arylation of sulfonamides with a variety of aryl bromides and iodides using microwave heating is described.     

Copper-catalyzed cross-coupling of diethyl phosphonate with aryl iodides

Cross-coupling of diethyl phosphonate with aryl iodides was performed using copper(I) iodide complexes with various bidentate ligands as catalysts.     

One-pot synthesis of monosubstituted aryl(hetaryl)acetylenes by direct introduction of the CCH residue into arenes and hetarenes

A convenient one-pot synthesis of aryl(hetaryl)acetylenes by cross-coupling of aryl(hetaryl)iodides with acetylene in presence of PdCl₂(Ph₃)₂, CuI and K₂CO₃ in DMF has been developed.     

Efficient copper-catalyzed C-S cross-coupling of heterocyclic thiols with aryl iodides

A copper-catalyzed cross-coupling of heterocyclic thiols with aryl iodides is reported. The reaction was carried out in the presence of CuI (5 mol %), 1,10-phenanthroline (10 mol %) and K₂CO₃ (1.3 equiv) in DMF at 120 °C. A variety of heterocyclic sulfides were prepared in high selectivities and yields.     

Rhodium-catalyzed triarylphosphine synthesis via cross-coupling of aryl iodides and acylphosphines

Rhodium(I)-catalyzed C–P cross-coupling reaction with aryl iodides and acylphosphines was disclosed for a straight forward synthesis of triarylphosphines. The acylphosphines were successfully employed as both the phosphorus source and the ligand to the Rh(I) catalyst. The triarylphosphines could be afforded in a yield up to 98% with good toleration of wide functional groups.     

Revisiting the Hirao cross-coupling: improved synthesis of aryl and heteroaryl phosphonates

The palladium-catalyzed cross-coupling of dialkylphosphite with aromatic electrophiles (Hirao coupling) was re-investigated. Some limitations in terms of palladium loadings and substrate reactivity are alleviated with the use of Pd(OAc)₂ complexed to 1,1′-bis(diphenylphosphino)ferrocene (dppf) as a ligand. Various aryl and heteroaryl halides are employed to deliver both known and novel substituted phosphonates. The first examples of aryl chloride couplings are also reported.     

Rapid palladium-catalyzed aminations of aryl chlorides with aliphatic amines under temperature-controlled microwave heating

Rapid Buchwald-Hartwig amination of electron neutral and rich aryl chlorides and bromides have been achieved using temperature-controlled microwave heating. Primary and secondary aliphatic amines can be coupled with these substrates in good yields within a reaction time of only 10 min.     

Palladium catalyzed atom-efficient cross-coupling reactions of triarylbismuths with aryl bromides

Aryl bromides (3 equiv) were coupled efficiently with triarylbismuths (1 equiv) in an atom-efficient way using the Pd(OAc)₂/PPh₃ catalytic system in the presence of K₃PO₄ as base in DMF at 90 °C, providing excellent yields of the cross-coupled biaryls in short reaction times.     

Copper-catalyzed cyanation of aryl iodide with the combined cyanide source of urea and DMSO

A simple copper-catalyzed cyanation of aryl iodide with the combination of urea and dimethyl sulfoxide as a cyanide source is achieved, providing nitriles in moderate to good yields. This new approach represents an exceedingly practical and safe method for the synthesis of aryl nitriles.     

A new palladium catalyzed protocol for atom-efficient cross-coupling reactions of triarylbismuths with aryl halides and triflates

A new palladium catalyzed protocol for an atom-efficient cross-coupling reaction of triarylbismuths with aryl halides and triflates has been described. The palladium catalytic system with Cs₂CO₃ base was found to be very efficient in DMA solvent to furnish excellent yields of cross-coupled functionalized biaryls in short reaction times.     

Cobalt-catalyzed cross-coupling reactions of alkyl halides with aryl Grignard reagents and their application to sequential radical cyclization/cross-coupling reactions

Reactions of alkyl halides with arylmagnesium bromides in the presence of cobalt(II)(diphosphine) complexes are discussed. Treatment of 1-bromooctane with phenylmagnesium bromide with the aid of a catalytic amount of CoCl₂(dppp) [DPPP=1,3-bis(diphenylphosphino)propane] yielded octylbenzene in good yield. The reaction mechanism would include single electron transfer from an electron-rich cobalt complex to alkyl halide to generate the corresponding alkyl radical. The mechanism was justified by CoCl₂(dppe)-catalyzed [DPPE=1,2-bis(diphenylphosphino)ethane] sequential radical cyclization/cross-coupling reactions of 6-halo-1-hexene derivatives that yielded benzyl-substituted cyclopentane skeletons.     

Copper-catalyzed trifluoromethylation of aryl iodides with potassium (trifluoromethyl)trimethoxyborate

Potassium (trifluoromethyl)trimethoxyborate is introduced as a new source of CF(3) nucleophiles in copper-catalyzed trifluoromethylation reactions. The crystalline salt is stable on storage, easy to handle, and can be obtained in near-quantitative yields simply by mixing B(OMe)(3), CF(3)SiMe(3), and KF. The trifluoromethylation reagent allows the conversion of various aryl iodides into the corresponding benzotrifluorides in high yields under mild, base-free conditions in the presence of catalytic quantities of a Cu(I)/1,10-phenanthroline complex.     

Synthesis of 1,1-diaryl ethylenes by Cu-catalyzed arene C-H addition to aryl acetylenes

An unprecedented copper-catalyzed C-H addition of arenes to aryl acetylenes provides a facile route to 1,1-diaryl ethylenes in moderate to excellent yields. Arylboronic acids were likewise used along with aryl acetylenes in generating 1,1-diaryl ethylene.     

Copper-catalyzed direct preparation of diaryl sulfides from aryl iodides using potassium thiocyanate as a sulfur transfer reagent

A method for direct preparation of diaryl sulfides from aryl iodides using potassium thiocyanate as a sulfur-transfer agent is reported. A catalyst system comprising of a simple copper salt, tetrabutylammonium bromide as a phase-transfer agent and water as the solvent is used. Microwave heating at 200 °C for 60 min allows for the conversion of a range of aryl iodides to the corresponding diaryl sulfides.     

Pd-catalyzed decarboxylative couplings of arenecarboxylic acids with aryl iodides

The combination of palladium chloride with BINAP shows high efficiency in the decarboxylative cross-coupling reactions of arenecarboxylic acids with aryl iodides. The reactions proceed smoothly to generate the corresponding biaryl compounds in good to excellent yields.