Iron-catalyzed alkyl-alkyl suzuki-miyaura coupling

Chemoselective Suzuki-Miyaura coupling of primary and secondary alkyl halides is realized by using an iron/Xantphos catalyst. Primary and secondary alkyl bromides undergo the reaction to give the coupling products in good yields. Application to the synthesis of long-chain fatty acid derivatives is also described.     

Intramolecular arylation of benzimidazoles via Pd(II)/Cu(I) catalyzed cross-dehydrogenative coupling

Electron poor benzimidazole substrates were arylated via an intramolecular cross-dehydrogenative coupling (CDC) reaction. These CDC reactions were catalyzed by a Pd(II)/Cu(I) catalyst system, capable of producing moderate yields on a large library of substrates. The substrate scope consisted of tethered arene-benzimidazoles that upon coupling, produced a fused polycyclic motif.     

Iron-catalyzed conversion of unactivated aryl halides to phenols in water

Although iron is low-cost and environmentally friendly, there is no report about iron-catalyzed conversion of unactivated aryl halides to phenols. In this Letter, a new method for the present conversion was developed with iron compounds as the catalyst and water as the solvent. The suggested method allowed a series of unactivated aryl bromides and aryl iodides to be converted into the corresponding substituted phenols in moderate to high yields.     

Iron-catalyzed benzamide formation. Application to the synthesis of moclobemide

A convenient and user-friendly method to yield benzamides from primary and secondary amines and various benzylic alcohols in the presence of a cheap iron salt (FeCl₂·4H₂O) and tert-butylhydroperoxide (70% in water) as a stoichiometric oxidant is described. Control experiments indicated that this reaction might involve radical species. This method proved to be general, generating a family of 30 benzamides and was applied to the preparative synthesis of anti-anxiety drug moclobemide.     

Iron-catalyzed cross-dehydrogenative CN coupling of thiohydantoins with various amines

A novel iron-catalyzed CN bond construction method for the hetero-cross-dehydrogenative coupling (CDC) of diverse thiohydantoins with amines utilizing TBHP as the oxidant was developed. This sp³ CH amination at the carbons alpha to carbonyl groups of thiohydantoin tolerates the presence of a wide range of functional groups and provides the corresponding N-substituted amines in moderate to good yields. Various substrate scopes and optimum reaction conditions leads inside in organic synthesis.     

Iron-catalyzed synthesis of phenanthrenes via intramolecular hydroarylation of arene-alkynes

An Fe(OTf)₃-catalyzed intramolecular hydroarylation of arene-alkynes with high functional group tolerance has been reported, affording a series of phenanthrene derivatives efficiently. A low catalytic amount of Fe(OTf)₃ is applied in this reaction. This transformation provides a convenient and practical method for the preparation of phenanthrenes.     

Iron-catalyzed aerobic oxidative cross-coupling amidation of N,N-dimethylanilines

An efficient iron-catalyzed dehydrogenative cross-coupling amidation/imidation reaction between N,N-dimethylanilines and amides/imides is reported. The protocol uses an inexpensive and readily available Fe(NO₃)₃·9H₂O/O₂ catalytic system in the absence of additional ligands at room temperature.     

Cross-couplings of alkyl halides with heteroaromatic halides, in water at room temperature

Zn-mediated, Pd-catalyzed cross-coupling reactions between heteroaromatic and alkyl halides can be done at room temperature in pure water using a commercially available Pd catalyst and PTS, a nanomicelle-forming amphiphile. Notably, zinc metal inserts selectively into a carbon sp³-halide bond, while palladium adds oxidatively to a carbon sp²-bond.     

Recent metallosurfactants for sustainable catalysis in water

In the field of green chemistry, micellar catalysis plays a central role for organic solvent replacement. Micelles ensure the solubilization or dispersion of catalyst and organic substrates in water imparting unique features in terms of chemo-, regio- and stereoselectivity. For metal-catalyzed reactions, a more robust approach for catalyst recycling consists in the synthesis of so-called metallosurfactants, in which a hydrophilic metal–containing headgroup is endowed with a hydrophobic ponytail, leading in water to the formation of metallomicelles. This fast-growing field of research is critically reviewed in this contribution, describing new trends and classifying the literature since 2017 based on the nature of the newly formed bond. Particular emphasis is reported on the specific features of metallosurfactants in terms of activities, selectivities and recyclability of the self-assembling catalysts.     

Iron-catalyzed Michael reactions revisited: a synthetically useful process for the preparation of tri-carbonyl compounds and chiral warfarin

The LBAs (Lewis acid-assisted Brønsted acid catalysis) is proposed as possible mechanistic process in the simple FeCl₃-catalyzed Michael reactions of chalcones with active methylene compounds in organic solvents. And iron salts were found to be effective promoters in the asymmetric Michael addition of 4-hydroxycoumarin to α,β-unsaturated ketone, which resulted in excellent yield and high level of enantioselectivity (up to 91% ee) in the presence of low catalytic amount of iron and simple chiral primary amine.     

Iron-catalyzed cascade reaction of ynone with o-aminoaryl compounds: a Michael addition-cyclization approach to 3-carbonyl quinolines

An efficient iron-catalyzed cascade Michael addition-cyclization of o-aminoaryl compounds including o-aminoaryl aldehydes, o-aminoaryl ketones, and o-aminobenzyl alcohols with ynones for the synthesis of 3-carbonyl quinolines is reported. The reactions proceed to afford 3-carbonyl quinoline derivatives with or without substituent at the C-4 position in good to high yields using Iron(III) chloride hexahydrate as the catalyst in the air.