Hydrogen production from formic acid catalyzed by NHC–Cu complexes

• Orlando Santoro and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2026, 22, 620–627, doi:10.3762/bjoc.22.48

• equimolar mixture of H2 and CO2. The efficiency of the catalysis showed to be strongly dependent on the nature of the amine. Keywords: copper N-heterocyclic carbene; formic acid dehydrogenation; hydrogen storage; metal hydride; silanes; Introduction The discovery and utilization of alternative and

• formate products. Excess H2 can be generated by dehydrogenative coupling of those species in the presence of the copper catalyst. Indeed, metal hydride systems have shown high catalytic activity in such a reaction [59][60]. In addition, the formation of products compatible with the polymerization of

Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis

• Peng-Xi Luo,
• Jin-Xuan Yang,
• Shao-Min Fu and
• Bo Liu

Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177

• moderate diastereoselectivity; this was followed by Mn(III)-catalyzed metal-hydride hydrogen atom (MHAT) transfer to reduce the endocyclic olefin, forming 41 as a single diastereomer. Subsequent transformations – including a Wittig reaction, demethylation, and oxidation of the resulting phenol to a p

Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

• homoallylic alcohols 18/19 via metal hydride atom transfer/radical polar crossover (MHAT/RPC) method (Scheme 6) [41]. This mild and high-yielding protocol displays good functional group tolerance and has a broad substrate scope, even providing access to medicinally relevant spirooxetanes. The proposed MHAT

Transition-metal-catalyst-free electroreductive alkene hydroarylation with aryl halides under visible-light irradiation

• Kosuke Yamamoto,
• Kazuhisa Arita,
• Masami Kuriyama and
• Osamu Onomura

Beilstein J. Org. Chem. 2024, 20, 1327–1333, doi:10.3762/bjoc.20.116

• intermediates through a single-electron transfer process [26][27][28][29][30][31]. In particular, electroreductive transformations have recently received renewed attention from modern synthetic chemists as a safer protocol than conventional methods using chemical reductants such as metal hydride species [32][33

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

• to the scientific community [10][11][12]. In this process, first, the metal-catalyzed dehydrogenation of the alcohol provides a reactive substrate for coupling with nucleophiles and the active metal hydride species. Later, the borrowed hydrogen is used in the final step to reduce unsaturated

Advancements in hydrochlorination of alkenes

• Daniel S. Müller

Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72

• interest as the starting materials are inexpensive bulk chemicals and the reactions can be carried out under air without any particular precautions. Radical hydrochlorination reactions Cobalt and iron-promoted radical hydrochlorination reactions are part of the large family of metal hydride hydrogen atom

• yield). Metal hydride hydrogen atom transfer reactions vs cationic reactions; BDE (bond-dissociation energy). Mechanism for the cobalt hydride hydrogen atom transfer reaction reported by Carreira. Proposed mechanism for anti-Markovnikov hydrochlorination by Nicewicz. Mechanism for anti-Markovnikov

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

• (versus NHE), respectively [3]. However, the molecular hydrogen evolution might compete, as it occurs at a more favorable reduction potential, lowering the selectivity of the catalytic system. While the addition of a proton source is beneficial to lower the overpotential, a metal-hydride (M–H

• possible. In some cases, this metal hydride favors the production of formate [51]. However, it may induce the concomitant formation of H2. This might have been the case of the photo-driven catalysis by complex 1 in DMA/TEOA (Table 2, entries 2–4), where upon decreasing the concentration of TEOA down to

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• heterocycles, because of its diverse presence in bioactive molecules [1][2][3][4][5][6][7][8], coupled with the distinct nucleophilic chemistry revolving its aromatic benzo-fused pyrrole system as encountered throughout the bibliography [9][10][11][12][13][14][15]. It is therefore obvious that a non-metal

• hydride will become exceptionally crucial when its hydrogen atoms are replaced by this special heterocycle, forming a multi-indolyl hetero non-metallide. In contemporary period, the said molecules have earned extensive importance in pharmacology to prevent cancer of a number of human organs, certified by

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

• as precursors of nucleophilic radical species in metal hydride hydrogen atom transfer reactions. This unique reactivity, combined with the wide availability of olefins as starting materials and the success reported in the construction of all-carbon C(sp3) quaternary centers, makes hydroalkylation

• suggested that iridium serves as a π-Lewis acid (although one could propose a C–H activation pathway) that activates the olefin by coordination due to the correlation observed between the nature of the Ir counterion and the reaction yields. Radical-based approaches Olefin hydroalkylation via metal hydride

• atom transfer Since the mid-2000s and mainly in the present decade, olefin hydrofunctionalization via metal hydride hydrogen atom transfer (MHAT) has gained increasing attention as a powerful tool for the functionalization of non-activated alkenes [48][49][50][51][52][53][54]. MHAT involves the

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

• imine with (RS,E) configuration. When the reduction is performed with ʟ-selectride, with the poorly coordinating metal hydride, an open transition state operates due to the bulkiness of the isobutyl groups bonded to the boron atom. In this case, the attack of the hydride takes place to the less hindered

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• , together with a metal hydride or a low-valent metal complex. Hence, in order to reoxidize the metal catalyst, excess of an external oxidant, such as Cu(II) or Ag(I) salts, was frequently used. On the other hand, photoredox catalysis has been mainly employed for electron-transfer reactions and, remarkably

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• . Water can lead to the formation of catalytically inactive Ru hydride species. Fürstner et al. isolated these complexes as byproducts during the synthesis of Grubbs second generation-type catalysts with saturated NHC ligands [29]. In this specific case, the formation of the metal hydride complex is

Catalysis of linear alkene metathesis by Grubbs-type ruthenium alkylidene complexes containing hemilabile α,α-diphenyl-(monosubstituted-pyridin-2-yl)methanolato ligands

• Tegene T. Tole,
• Johan H. L. Jordaan and
• Hermanus C. M. Vosloo

Beilstein J. Org. Chem. 2019, 15, 194–209, doi:10.3762/bjoc.15.19

• an increase in IPs) indicates decomposition of the precatalyst to active isomerisation species, probably metal hydride species. In our NMR study no indication of the existence of metal hydride species was found. Conclusion The aim of our research is to control the Ru–N bond strength of the bidentate

A selective removal of the secondary hydroxy group from ortho-dithioacetal-substituted diarylmethanols

• Anna Czarnecka,
• Emilia Kowalska,
• Agnieszka Bodzioch,
• Joanna Skalik,
• Marek Koprowski,
• Krzysztof Owsianik and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2018, 14, 1229–1237, doi:10.3762/bjoc.14.105

• such diarylmethanols [60], as well as Cl, Br, C(O)OMe, MeO, MeS and NO2 groups in aromatic aldehydes and ketones, being reduced to methyl and methylene groups, respectively [27], are tolerated by this reagent system. The use of other procedures for deoxygenation of alcohols 5d, 6a and 6b with metal

• hydride donors, such as NaBH4 and LiAlH4 in various combinations with ZnI2 and AlCl3 failed [61][62][63]. For instance, the reaction with NaBH4 itself and NaBH4/ZnI2/THF at room temperature and reflux only recovered the substrates. The same result was obtained at room temperature with NaBH4/AlCl3/THF

Rh-Catalyzed rearrangement of vinylcyclopropane to 1,3-diene units attached to N-heterocycles

• Franca M. Cordero,
• Carolina Vurchio,
• Stefano Cicchi,
• Armin de Meijere and
• Alberto Brandi

Beilstein J. Org. Chem. 2011, 7, 298–303, doi:10.3762/bjoc.7.39

• bond to form the intermediates C which can undergo metal hydride elimination or 1,3-hydride migration to the rhodium to give, respectively, the allyl- and alkylrhodium(III) hydride complexes D and F. Metal extrusion by reductive elimination leads to the observed dienes and regeneration of the catalyst

About the activity and selectivity of less well-known metathesis catalysts during ADMET polymerizations

• Hatice Mutlu,
• Lucas Montero de Espinosa,
• Oĝuz Türünç and
• Michael A. R. Meier

Beilstein J. Org. Chem. 2010, 6, 1149–1158, doi:10.3762/bjoc.6.131

• [13][14][15][16][17]. In a number of other publications this problem was addressed and further discussions on the possible mechanism of the two proposed pathways, the π-allyl metal hydride and the metal hydride addition-elimination mechanisms, were reported [8][11][13][14][15][16][17][18]. In most

• efficiently isomerizing terminal olefins is a clear indication that metal hydride species are indeed the source of the isomerization. It was reported that a proper selection of solvents and additives can eliminate isomerization with Ru-based metathesis catalysts in RCM [16]. The addition of POCy3 or oxygen