Iron-Mediated One-Pot Dehydroxylative Cross-Electrophile Coupling of Alcohol with Disulfide for Thioether Synthesis by Using TCT as a Hydroxyl-Activating Agent

An efficient dehydroxythiolation between alcohols and disulfides using the widely abundant and cheapest iron as a reaction mediator was developed. The one-pot thiolation proceeded effectively via C-O bond activation with the aid of cyanuric chloride (TCT) as a hydroxyl-activating agent to give the corresponding thioethers in modest to excellent yields, displaying both a wide substrate scope (applicable to benzyl alcohol, allyl alcohol, and primary alkyl alcohol) and good functional group tolerance. In addition, diselenide was also proven to be an appropriate substrate for the protocol, and the reaction could be subjected to scale-up synthesis. Preliminary mechanistic examination revealed that transiently formed TCT-derived ether A, which is generated in situ via the reaction of TCT with alcohol, possibly serves as the pivotal intermediate of the cross-electrophile thioetherification.

Mechanisms of Activating Agents to Form Organozinc Reagents from Zinc Metal: Lessons for Reaction Design

Activating agents enable the efficient preparation of organozinc complexes from zinc metal and organohalides, but their mechanisms had been obscured by the heterogeneous nature of these systems. Fluorescence microscopy, with the sensitivity to detect surface reaction intermediates, reveals distinct activating mechanisms of widely used activation strategies: trimethylsilyl chloride, LiCl, DMSO, and Rieke zinc powder. The resulting development of mechanistic models provides a better understanding of the oxidative-addition-solubilization sequence in organozinc reagent formation and contains lessons for methods development.

Iron-Mediated Reductive Amidation of Triazine Esters with Nitroarenes

A reductive amidation of triazine esters with nitroarenes by using cheap iron as a reducing metal in the presence of TMSCl in DMF was developed. The reactions proceeded efficiently under transition metal-free conditions to give the corresponding amides in moderate to good yields with good functional group compatibility. Preliminary mechanistic investigations indicated that nitrosobenzene, N-phenyl hydroxylamine, azoxybenzene, azobenzene, aniline, and N-arylformamide possibly served as the intermediates of the reaction.

Cathodic Carbonyl Alkylation of Aryl Ketones or Aldehydes with Unactivated Alkyl Halides

An efficient cathodic carbonyl alkylation of aryl ketones or aldehydes with unactivated alkyl halides has been realized through the electrochemical activation of iron. The protocol is believed to include a radical-radical coupling or nucleophilic addition process, and the formation of ketyl radicals and alkyl radicals has been demonstrated. The protocol provides various tertiary or secondary alcohols by the formation of intermolecular C-C bonds under safe and mild conditions, is scalable, consumes little energy, and exhibits a broad substrate scope.

Stereoselective synthesis of fluoroalkylated (Z)-alkene via nickel-catalyzed and iron-mediated hydrofluoroalkylation of alkynes

An efficient nickel-catalyzed, iron-mediated hydrofluoroalkylation of alkynes with bromodifluoroacetate or perfluoroalkyl iodide, which proceeded smoothly to give fluoroalkylated (Z)-alkenes with high stereocontrol (up to 99 : 1 Z/E), was developed.

Room temperature iron(ii)-catalyzed radical cyclization of unsaturated oximes with hypervalent iodine reagents

An iron(ii)-catalyzed radical cyclization of oximes with hypervalent iodine reagents was developed, which enabled the construction of the isoxazoline backbone.

Iron(0)-Mediated Reformatsky Reaction for the Synthesis of β-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 β-hydroxyl carbonyl compounds in moderate to good yields.