Light Runs Across Iron Catalysts in Organic Transformations

Abstract

Over the past decades, organometallic complexes with precious elements, such as ruthenium and iridium, are widelyu sed as visible-light photoredox catalysts. Recently,m ore and more complexes based on earthabundant andi nexpensive elementsh ave been used as sensitizers in photochemistry.A lthough the photoexcited state lifetimes of iron complexes are typically shortert han those of traditional photosensitizers, the utilization of iron catalysts in photochemistry has sprung up owing to their abundance, low price, nontoxicity,a nd novel properties, including exhibiting ligand to metal charge transfer states. This concept focuses on recent advances in light-driven iron catalysis in organic transformations, including iron/ photoredox dual catalysis,l ight-inducedi ron photoredox catalysis and light-induced generation of active iron catalysts. The prospectf or the future of this field is also discussed.

Synthesis and Characterization of Bidentate Isonitrile Iron Complexes

“…Extending this concept to iron holds the promise of making this metal broadly available for photocatalysis. This is especially challenging, given that excited-state lifetimes of iron complexes are often in the picosecond range and have been reported at best in the low-nanosecond range . However, there is only limited data available on coordination complexes of iron with bidentate isonitriles, − in contrast with monodentate isonitrile iron complexes, which have attracted considerable attention due to the high prevalence of iron carbonyl complexes .…”

Visible Light‐Induced Synthesis of Functionalized Coumarins

“…Besides, the reaction also afforded the natural products urolithins (79 a, 79 The merging of visible light photoredox chemistry with iron catalysis constitutes a highly versatile approach to sophisticated organic synthesis. [54] In this context, a visible light-driven lactonization of 2arylbenzoic acids 68 was achieved by Lie and coworkers by employing [Fe(NO 3 ) 3 ] . 9H 2 O, NaBrO 3 , 2,2'bipyridine-6,6'-dicarboxylic acid, and HFIP as a catalyst, oxidant, ligand, and solvent respectively (Scheme 27 (b)).…”

“…The merging of visible light photoredox chemistry with iron catalysis constitutes a highly versatile approach to sophisticated organic synthesis [54] . In this context, a visible light‐driven lactonization of 2‐arylbenzoic acids 68 was achieved by Lie and co‐workers by employing [Fe(NO 3 ) 3 ] .…”

Synthesis and Characterization of Bidentate Isonitrile Iron Complexes

“…This is especially challenging given that excited-state lifetimes of iron complexes are often in the picosecond range and have been reported at best in the low nanosecond range. [10] However, there are only limited data available on coordination complexes of iron complexes with bidentate isonitriles, [18]- [21] contrasting monodentate isonitrile iron complexes, which have attracted considerable attention due to the high prevalence of iron carbonyl complexes. [11] For example, dinuclear iron complexes such as [CpFe(CNPh)2] [12] (A, Ph = C6H5) or [Fe2(CNPh)9] [13] (B) feature terminal and bridging isonitrile ligands (Figure 1).…”