Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• properties of transition metals and Lewis acids [69][70][71][72]. These advantages make iron salts attractive catalysts or reagents in chemical transformations and are considered ideal materials for developing catalysts [73]. Fe-catalyzed CDC reactions have achieved remarkable achievements in recent years

Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

• . altamirensis DSM 44997, the bacterium was grown in minimal medium without the addition of iron salts. Initial evidence for siderophore production was obtained from a chrome azurol S (CAS) assay [9], which showed a clear color change from blue to pink upon testing of the culture broth. Several batch

Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• /hydroalkoxylation of alkynes was also reported (Scheme 8). Vogel and co-workers demonstrated the Sonogashira cross-coupling reaction of aryl iodides with terminal alkynes by utilizing cheap, non-toxic iron salts and copper iodide (Scheme 9) [26]. The reaction of 4-iodotoluene with phenylacetylene was chosen as the

• model reaction without any external ligand and required 20 h for completion. However, the same reaction under microwave irradiation was complete within 2.5 h. The product was obtained with an excellent yield of 95% by the utilization of Fe(III) acetylacetonate and CuI as the catalyst. Among several iron

• salts tested Fe(III) acetylacetonate seemed to be the best catalyst. In order to outstretch the scope of the reaction phenylacetylene was coupled with various electrophilic partners. Liu et al. developed a catalytic system for the cross-coupling of aryl iodides with alkynes by the use of a combination

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• which will react further. However, reactions catalyzed by the Lewis-acidic character of iron salts are beyond the scope of this review. Iron also has the ability to transfer one or two electrons to a substrate. This opens the possibility for radical reactions via a single electron transfer (SET). Once

• explored using chloroalkanes to form di- and trichlorinated products 150. Despite previous reports demonstrating dichloromethane 139b in the presence of peroxide [126] and iron salts [127] form 1,1,1- and 1,1,1,3-substituted chloroalkanes, under the authors’ optimized reaction conditions only the

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• that has been done so far. From the simplest iron salts to the most enantiospecific complex forms, iron catalysis is playing an important role for the development of additional accessible C–H activation methods. From these perspectives it can be assumed that in the near future iron will be one of the

Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

• Thiago S. Silva and
• Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

• -coordinating anion OCl− and as an activator of the gold(I) complex in these reactions. Other metals Although gold catalysis predominates in these types of reactions, inexpensive iron salts have also been employed successfully in hydroalkylation reactions. In 2007, Beller and co-workers reported the

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

Access to highly substituted oxazoles by the reaction of α-azidochalcone with potassium thiocyanate

• Mysore Bhyrappa Harisha,
• Pandi Dhanalakshmi,
• Rajendran Suresh,
• Raju Ranjith Kumar and
• Shanmugam Muthusubramanian

Beilstein J. Org. Chem. 2020, 16, 2108–2118, doi:10.3762/bjoc.16.178

• of iron salts and solventsa. Supporting Information Supporting Information File 518: Full experimental details, compound characterisation, and copies of NMR spectra. Funding M. B. H. is grateful to Eurofins-Advinus Limited, Bangalore for support. P. D. thanks the Science and Engineering Research

Enantioselective Diels–Alder reaction of anthracene by chiral tritylium catalysis

• Qichao Zhang,
• Jian Lv and
• Sanzhong Luo

Beilstein J. Org. Chem. 2019, 15, 1304–1312, doi:10.3762/bjoc.15.129

• , Scheme 3a). The electron-rich nature of dimethylanthracene may account for catalysis with the iron salts. On the other hand, an opposite chiral induction in this case is a clear indication of distinctive carbocation catalysis instead of metal Lewis acid catalysis in the presence of trityl chloride. In

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

Recent advances in transition-metal-catalyzed intermolecular carbomagnesiation and carbozincation

• Kei Murakami and
• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 278–302, doi:10.3762/bjoc.9.34

• ). Recently, iron and cobalt have been regarded as efficient catalysts for carbometalation of simple alkynes. Shirakawa and Hayashi reported that iron salts could catalyze arylmagnesiation of arylacetylenes in the presence of an N-heterocyclic carbene (NHC) ligand (Scheme 29) [103]. In 2012, Shirakawa and

Homocoupling of aryl halides in flow: Space integration of lithiation and FeCl₃ promoted homocoupling

• Aiichiro Nagaki,
• Yuki Uesugi,
• Yutaka Tomida and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2011, 7, 1064–1069, doi:10.3762/bjoc.7.122

• reoxidant, such as oxygen or other organic oxidants, are effective. Recently, iron salts have been also used because of their low costs and lack of toxicity [8][9][10][11][12][13][14][15][16][17][18]. For example, Hayashi et al. reported the iron-catalyzed oxidative homocoupling of Grignard reagents, using

• generated by halogen–lithium exchange under homogeneous conditions, thus enabling the generation in a flow. However, to the best of our knowledge, oxidative homocoupling of aryllithiums using iron salts has not been reported so far. One of the major reasons for this seems to be the instability of

• homocoupling of aryllithiums, and this enabled its integration with the halogen–lithium exchange reaction of aryl halides in a flow microreactor. This system allows the homocoupling of two aryl halides bearing electrophilic functional groups, such as CN and NO2, in under a minute. Keywords: homocoupling; iron

Gold-catalyzed heterocyclizations in alkynyl- and allenyl-β-lactams

• Benito Alcaide and
• Pedro Almendros

Beilstein J. Org. Chem. 2011, 7, 622–630, doi:10.3762/bjoc.7.73

• functional molecules, and therefore, their stereocontrolled synthesis remains an important research area. On the other hand, the recent resplendent age of gold has been accompanied by the emergence of iron salts as powerful alternatives in view of their inexpensiveness and environmental friendliness [38][39