Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• . Studies showed that a Mn catalyst is critical for synthesizing derivatives of phenanthridine-based diarylphosphine oxides. The reaction yield decreased in the absence of the ligand, and eliminating both the ligand and manganese salt suppressed the reaction. Moreover, a slight decrease in the reaction

• using manganese acetate as a catalyst is essential, and the reaction failed to produce any product without the catalyst. Other catalysts besides Mn were tested, but they showed poor reactivity. Other strong polar solvents were also used in this method, but they resulted in lower yields of the products

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• -butoxy radical C, which can abstract the hydrogen atom from TBHP to form tert-butylperoxy radical B. The alternative pathway for the formation of radical B is the oxidation of TBHP with complex A. A manganese-catalyzed radical approach for the remote trifluoromethylation–peroxidation of non-activated

• fluorenes 51 peroxidation (Scheme 19) [50][62]. Initially, the complex A of 2,2′-bipyridine with manganese(III) acetate is formed. Further oxidation of A by TBHP leads to complex B and tert-butoxy radical C. The later one abstracts an hydrogen atom from fluorene 51 to form C-centered radical F. The reaction

• ]. It was shown that manganese salts in various oxidation states catalyze the peroxidation of styrenes with TBHP [129]. A method was proposed for the synthesis of [1,2-bis(tert-butylperoxy)ethyl]arenes 195 from styrenes 194 under Mn(OAc)3 catalysis (Scheme 61). The formation of active peroxidising

Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

• Yukiko Karuo,
• Keita Hirata,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

• reagents have been developed. These reagents are easily being converted into multisubstituted fluoroalkenes through cross-coupling using palladium, nickel, copper, ruthenium, and manganese catalysts [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]. Hosoya and Niwa et al. published the

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

• this method (Scheme 30b). 1.3 Metal-assisted anodic oxidation 1.3.1 Mn-assisted anodic oxidation. The Ackermann group was the first to achieve an C–H azidation by use of a manganese-catalyzed anionic oxidation using “traceless electrons” [42]. By employing inexpensive sodium azide and a manganese salen

• undergoes hydrogen-atom transfer (HAT) leading to alkyl radical formation. The manganese-catalyzed azide radical transfer then delivers the product. Unactivated secondary and tertiary C–H bonds, as well as benzylic C–H bonds, were prone to azidation, with the reactivity order being: benzylic > tertiary

• conditions, a combination of a manganese (Mn) catalyst and NaN3 delivered the azidation product. This protocol was effective for azidating unactivated secondary and tertiary carbon bonds as well as benzylic C–H bonds and was applied to the LSF of certain drugs and natural products. Mechanistic studies led

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

• Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

• aldehyde-derived hydrazones 114 and diarylphosphine oxide 115. The phosphorylation proceeded with slightly higher yield in the presence of a catalytic amount of manganese dibromide but its role was not clearly identified. Cyclic voltammetry analysis supported the initial oxidation of the hydrazone (Ep/2 of

Access to 2-oxoazetidine-3-carboxylic acid derivatives via thermal microwave-assisted Wolff rearrangement of 3-diazotetramic acids in the presence of nucleophiles

• Ivan Lyutin,
• Vasilisa Krivovicheva,
• Grigory Kantin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 1894–1899, doi:10.3762/bjoc.20.164

• cyclization [15][16]. Additionally, the manganese(III)-promoted cyclization of N-alkenyl malonamides [17][18] and the Cu(I)-catalyzed reaction of propiolic acid derivatives with nitrones (Kinugasa reaction) [19][20][21] should also be mentioned, as well as intramolecular C–H insertion using

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• compounds were hydrogenated, oxidized, and lactonized in a similar fashion, utilizing either the Jones reagent or manganese dioxide as the oxidizing agent [18]. Santhamma et al. developed another route for steroidal spiro-γ-lactones at C-17, from estran-17-one and androstane-17-one derivatives [19]. The

Oxidation of benzylic alcohols to carbonyls using N-heterocyclic stabilized λ³-iodanes

• Thomas J. Kuczmera,
• Pim Puylaert and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 1677–1683, doi:10.3762/bjoc.20.149

• easily overoxidized to carboxylic acids. Over the past decades a variety of methods have been developed, utilizing toxic heavy metals such as pyridinium dichromate (PDC) [3][4][5] or manganese dioxide (Figure 1) [6][7]. Molecular oxygen [8] and peroxides [9][10] can also be used as inexpensive terminal

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• -methylquinoline derivatives could be fluorinated in yields of up to 70%. In 2013, Groves and co-workers reported the use of manganese salen and manganese porphyrin catalysts in the preparation of a range of secondary benzyl fluorides via C–H fluorination (Figure 31) [80]. Substrates bearing electron-withdrawing

• fluoride. Manganese-catalysed benzylic C(sp3)–H fluorination with AgF and Et3N·3HF and proposed mechanism. 19F NMR yields in parentheses. Iridium-catalysed photocatalytic benzylic C(sp3)–H fluorination with nucleophilic fluoride and N-acyloxyphthalamide HAT reagent. Iridium-catalysed photocatalytic

Rhodium-catalyzed homo-coupling reaction of aryl Grignard reagents and its application for the synthesis of an integrin inhibitor

• Kazuyuki Sato,
• Satoki Teranishi,
• Atsushi Sakaue,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai,
• Hiroyuki Takeda,
• Tatsuo Kinashi and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 1341–1347, doi:10.3762/bjoc.20.118

• . Therefore, alternative procedures for homo-coupling reactions using other transition-metal catalysts such as palladium, nickel, manganese, and iron have been developed [5][6][7][8][9][10][11][12][13]. In recent years, transition-metal-free coupling reactions have also been developed for environmentally

Manganese-catalyzed C–C and C–N bond formation with alcohols via borrowing hydrogen or hydrogen auto-transfer

• Mohd Farhan Ansari,
• Atul Kumar Maurya,
• Abhishek Kumar and
• Saravanakumar Elangovan

Beilstein J. Org. Chem. 2024, 20, 1111–1166, doi:10.3762/bjoc.20.98

• reactions allow the sustainable construction of C–C and C–N bonds using alcohols as hydrogen donors. In recent years, manganese complexes have been explored as efficient catalysts in these reactions. This review highlights the significant progress made in manganese-catalyzed C–C and C–N bond-formation

• reactions via hydrogen auto-transfer, emphasizing the importance of this methodology and manganese catalysts in sustainable synthesis strategies. Keywords: alcohols; alkylation; amines; borrowing hydrogen; hydrogen auto-transfer; manganese; Introduction The construction of C–C and C–N bonds is of utmost

• considerably inexpensive, eco-friendly and more abundant in the Earth’s crust. According to this viewpoint, manganese is biocompatible and less expensive than noble metals. Also, it is the third most abundant transition metal, behind titanium and iron. After the independent pioneering works of Beller [16] and

Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria

• Kara A. Strickland,
• Brenda Martinez Rodriguez,
• Ashley A. Holland,
• Shelby Wagner,
• Michelle Luna-Alva,
• David E. Graham and
• Jonathan D. Caranto

Beilstein J. Org. Chem. 2024, 20, 830–840, doi:10.3762/bjoc.20.75

• was attributed to a manganese peroxidase, however, the mechanism of degradation is unclear. Linear nitramines, produced by carbon capture, were shown to be biodegraded in soil and water [19]. Nitramines with hydroxy groups were best degraded in this study, including diethylnitramine, 2-methyl-2

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• reductant, which can be an organic reductant, such as tetrakis(N,N-dimethylamino)ethylene (TDAE) or Hantzsch ester (HE), or a metal such as zinc (Zn0) or manganese (Mn0). Upon fragmentation, radical species 12 is captured by the oxidative addition complex 125, giving rise to NiIII complex 126. The cross

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• ]. Among the most employed earth-abundant metal-based PS, Cu(I) complexes have the first place, not only in artificial photosynthesis, but also in a large variety of photo(redox)catalyses [12][13][14][15][16][17]. On the other hand, several complexes based on 3d transition metals, like manganese [18], iron

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• of coordination compounds of copper(II), iron(II/III), manganese(II), nickel(II), and cobalt(II) with 9-Zn and 9-Cu was demonstrated. The emission quenching was rationalised considering the binding of the transition metal within the crown ether cavity. No quenching was observed upon the addition of

• iron(II) and manganese(II) complexes with similar compositions. Interestingly, by-products incorporating the [2 + 2] macrocycles were isolated from the reaction mixtures targeting 16-Fe, 18a-Fe and 16-Mn, 18a-Mn (Figure 13) [67]. The helical geometry of [16-M]2 was attributed to the inherent

• flexibility of macrocyclic ligands, as demonstrated by X-ray molecular structures. The helicates consisted of two metal centres, namely cobalt, manganese, or iron, each coordinated by two nitrogens and oxygen donors of the ligand. The metal centres adopted distorted octahedral geometries with slight

Radical ligand transfer: a general strategy for radical functionalization

• David T. Nemoto Jr,
• Kang-Jie Bian,
• Shih-Chieh Kao and
• Julian G. West

Beilstein J. Org. Chem. 2023, 19, 1225–1233, doi:10.3762/bjoc.19.90

• behavior of P450 oxygenases encouraged early work on site-selective C–H functionalization [20]. Throughout their studies, it was found that manganese could perform the same HAT and RLT steps as iron at heme active sites. Groves developed the manganese tetramesitylporphine catalyst V (Scheme 2), which was

• found to be capable of functionalizing specific C–H bonds to numerous functionalities, including C–F [21][22], C–N3 [23], and C–Cl bonds [24][25]. Upon these remarkable observations, methodologies involving manganese–porphyrin catalysts have been developed over the years. These methods take advantage of

• the power of RLT to install a variety of medicinally relevant groups, largely mirroring the selectivity of CYP450s. Intriguingly, studies by Groves have revealed earth abundant iron and manganese to be particularly privileged for this application of RLT, a major advantage for sustainable method

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• sacrificial donors [40]. More recently, other groups have published the electrochemical hydrogenation of carbonyl compounds using more earth-abundant electrocatalysts. For instance, Siewert and co-worker used a manganese complex as an electrocatalyst for the chemoselective carbonyl hydrogenation [41

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• . Knell et al. [40][41] reported a comparison of several catalysts, which included potassium-promoted iron, cobalt and manganese oxide catalysts, for the synthesis of 1a. Industrially, 1a is produced by the vapour phase dehydration of 2a over an iron/potassium/chromium catalyst system (Scheme 4) [42]. 2

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• generation of radicals from carbonyl reduction [18] but also manganese(III) acetate as a convenient one-electron oxidant [19]. The next twenty years, the field continued to flourish mainly by way of the decipherment of hydrogen atom transfer (HAT) mechanisms, which led to the establishment of several

• ) [30]. HAT reductions of the C9–C11 alkene followed to deliver arisugacin F (35), phenylpyropene C (36), pyripyropene E (38), and phenylpyropene F (41). The steric bulk of the manganese catalyst employed suppressed the undesired reaction with tetrasubstituted alkenes and led to the exclusive reaction

Design, synthesis, and evaluation of chiral thiophosphorus acids as organocatalysts

• Karen R. Winters and
• Jean-Luc Montchamp

Beilstein J. Org. Chem. 2022, 18, 1471–1478, doi:10.3762/bjoc.18.154

• -catalyzed hydrophosphinylation [45]. The key heterocyclization of 11 into 12 was accomplished using silver-promoted homolytic aromatic substitution [46], which was superior to our own manganese methodology (43% yield) [36]. Copper-catalyzed arylation [34] of 12 with iodobenzene and 4-nitroiodobenzene gave

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

• Artem N. Semakin,
• Ivan S. Golovanov,
• Yulia V. Nelyubina and
• Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

• dynamic covalent libraries [25]. TAAD can be covalently bound to a polymer matrix through the nucleophilic nitrogen N(1) that was used to prepare scavengers of boronic acids [25]. Also, TAAD was demonstrated to serve as a scorpionate-type ligand for manganese and iron leading to complexes with the metal

Electrochemical vicinal oxyazidation of α-arylvinyl acetates

• Yi-Lun Li,
• Zhaojiang Shi,
• Tao Shen and
• Ke-Yin Ye

Beilstein J. Org. Chem. 2022, 18, 1026–1031, doi:10.3762/bjoc.18.103

• have reported a manganese dioxide-catalyzed radical azidation of enol acetates to afford the corresponding azidoketones using dioxygen as the oxidant (Scheme 1A) [14]. The adoption of electrosynthesis in green and sustainable redox transformations has been experiencing a dynamic renaissance [15][16][17

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• oxidant (Scheme 8B) [39]. The process is performed at 120 °C at 10 bar with a residence time of 6 min, and catalyzed homogenously utilizing the established “MC-system” (manganese/cobalt/bromide) in a heated tube reactor. Remarkably, acetophenone is obtained in a good yield of 66% and in 96% purity without

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• manganese(II) naphthenate (MnPc)-catalyzed oxidation of 16 to furnish 10 in 60% yield with 75.6% conversion and 80% selectivity (Table 1, entry 8) [54]. The MnPc catalyst improves the stability of H2O2 and thus promotes a selective oxidation [54]. The approach developed by Beller’s group, which applied a

• oxidizing agent in the presence of a mixture of chromium(III) and manganese(II) salts to furnish product 10 in 70% yield (Table 1, entry 16) [62]. The authors proposed that the oxidation involves an initial ozonation of the transition metal salts, which then oxidized substrate 16 to the desired product 10

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• substrate 26 was first modified at the hydroxy groups through esterification with a designed acid moiety possessing a p-tert-butylphenyl group and transformed to the corresponding model substrate 27. The catalyst H used here was a manganese(III)-bounded porphyrin module carrying four β-cyclodextrin units at