On the Use of Iron in Organic Chemistry

Abstract

Transition metal catalysis in modern organic synthesis has largely focused on noble transition metals like palladium, platinum and ruthenium. The toxicity and low abundance of these metals, however, has led to a rising focus on the development of the more sustainable base metals like iron, copper and nickel for use in catalysis. Iron is a particularly good candidate for this purpose due to its abundance, wide redox potential range, and the ease with which its properties can be tuned through the exploitation of its multiple oxidation states, electron spin states and redox potential. This is a fact made clear by all life on Earth, where iron is used as a cornerstone in the chemistry of living processes. In this mini review, we report on the general advancements in the field of iron catalysis in organic chemistry covering addition reactions, C-H activation, cross-coupling reactions, cycloadditions, isomerization and redox reactions.

A DFT Study on FeI/FeII/FeIII Mechanism of the Cross-Coupling between Haloalkane and Aryl Grignard Reagent Catalyzed by Iron-SciOPP Complexes

“…Transition-metal-catalyzed cross-coupling reaction is one of the most versatile synthetic tools for constructing carbon frameworks of various functional molecules, e.g., pharmaceuticals, agrochemicals, and organic electronic materials. Iron catalysts have emerged as a sustainable alternative for conventional palladium and nickel catalysts and have attracted significant attention due to their practical merits of cost-effectiveness, low toxicity, and the abundance on the earth [1][2][3][4]. Despite the remarkable progress of iron-catalyzed cross-coupling reactions in organic synthesis [5][6][7][8][9][10][11][12][13][14], their reaction mechanisms remain elusive and attract considerable interests to their underlying molecular mechanisms [15][16][17][18][19].…”

Iron-catalyzed cascade synthesis of nitrogen polycycles from alkynoic acids and functionalized amines

“…It has been known for long that iron can promote several organic transformations, but its catalytic role akin to that of some precious late transition metals remained unrevealed until recently. In addition to the wide range of oxidation states that iron can adopt (from − 2 to + 5), this convenient metal has the ability to transfer one or two electrons to a substrate, thus enabling not only radical reactions but also processes based on oxidative addition and reductive elimination steps (Rana et al 2021;Casnati et al 2020;DaBell and Thomas 2020;Zhang et al 2020;Guđmundsson and Bäckvall 2020;Piontek et al 2018;Wei and Darcel 2019;Bauer and Knölker 2015;Bolm et al 2014). In this regard, the activation of carbon-carbon triple bond of alkynes by iron Lewis acids, or even low-valent iron complexes, can promote several annulation, cycloisomerization (enyne derivatives and allenols) and other cyclization processes leading to the formation of several heterocycles such as benzo-and dihydrofurans, coumarines, quinolines, oxathiines, dibenzoxepines, benzocarbazoles and cyclobutane-fused pyrrolidines, inter alia (Gay et al 2010;Mantovani et al 2014;Wang et al 2011;Sonehara et al 2017;Yao et al 2012, Sivaraman andPerumal 2014;Teske and Plietker 2016;Fürstner et al 2008;Gudmundsson et al 2018, Kramm et al 2018Boominathan et al 2015;Sreedevi et al 2010).…”

Recent Advances in Iron‐Catalyzed Chemical and Enzymatic Carbene‐Transfer Reactions

“…However, the low abundance and high cost of some of the transition metals e. g. Rh, Pd, Ru, Ir etc. have moved the focus of synthetic chemists towards the use of highly abundant metals such as iron as a catalyst which is the second most abundant metal in nature [8] . Besides, iron is an integral part of various biological systems such as haemoglobin (Hb), myoglobin (Mb), cytochrome P450 and has ability to assume a range of oxidation state (−2 to +6).…”