Electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines under mild conditions with a proton-exchange membrane reactor

• Koichi Mitsudo,
• Atsushi Osaki,
• Haruka Inoue,
• Eisuke Sato,
• Naoki Shida,
• Mahito Atobe and
• Seiji Suga

Beilstein J. Org. Chem. 2024, 20, 1560–1571, doi:10.3762/bjoc.20.139

• ][34][35][36][37][38][39][40][41][42][43]. The PEM reactor included a membrane electrode assembly (MEA) consisting of a PEM and an electro-catalyst supported on carbon (Figure 1). Humidified hydrogen gas (H2) or H2O was injected into the anodic chamber and the substrate passed through the cathodic

• for a supporting electrolyte, which is necessary for conventional organic electrolysis, reduces the environmental impact, and facilitates product purification. In addition, using nanoparticles in the catalyst layer, which serve as the electrode, results in a large specific surface area and efficient

• semihydrogenation of alkynes to form Z-alkenes using a PEM reactor [31]. The Pd/C catalyst was essential for the reaction. They recently found that a PEM reactor with a Rh/C catalyst was effective for the stereoselective reduction of cyclic ketones [40]. Nagaki et al. reported the electrochemical deuteration of

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

• secondary and tertiary substrates too. In 2012, Lectka reported a fluorination of mostly aliphatic C–H bonds that used a molecularly defined copper catalyst with a bis imine ligand, along with co-catalytic N-hydroxyphthalimide and a phase-transfer catalyst [51]. Although only a few benzylic substrates were

• intramolecular fluorine-atom-transfer (FAT) from an N-fluorinated amide to a pendant carbon-based radical formed from an iron catalyst (Figure 15) [55][56]. This concept of fluorine transfer through a 6-membered transition state was shown to work efficiently from primary, as well as secondary, benzylic radicals

• photosensitive arylketone catalyst in the fluorination of phenylalanine residues in peptides (Figure 27) [72]. This work demonstrated high yields and selectivity for peptides bearing phenylalanine residues, including tripeptides, such as 16. In 2015, Britton and co-workers reported a photochemical HAT-guided

Primary amine-catalyzed enantioselective 1,4-Michael addition reaction of pyrazolin-5-ones to α,β-unsaturated ketones

• Pooja Goyal,
• Akhil K. Dubey,
• Raghunath Chowdhury and
• Amey Wadawale

Beilstein J. Org. Chem. 2024, 20, 1518–1526, doi:10.3762/bjoc.20.136

• primary amine catalysts (see Table S1 in Supporting Information File 1) in toluene at room temperature (30–32 °C). When the test reaction was conducted in the presence of 15 mol % of 9-amino-9-deoxy-epicinchonidine (I) as catalyst [30] for 12 h and treated with Ac2O followed by DABCO, the reaction gave

• File 1), the catalyst I imparted the highest enantioselectivity (74% ee) of the Michael product 3aa (Table 1, entry 1). Different solvents (see details in Supporting Information File 1) were screened for the test reaction using 15 mol % of catalyst I. Among them, CHCl3 turned out to be the optimal

• marked increase in both the yield and enantioselectivity of the product 3aa were observed. Among the screened Brønsted acids A1–6, the combination of 15 mol % of the catalyst I and 30 mol % of (±)-mandelic acid (A5) was found to be superior in terms of enantioselectivity (92% ee) of the product 3aa

Tetrabutylammonium iodide-catalyzed oxidative α-azidation of β-ketocarbonyl compounds using sodium azide

• Christopher Mairhofer,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1510–1517, doi:10.3762/bjoc.20.135

• carbonyl compounds (Scheme 1A). Hereby different strategies using different quaternary ammonium iodide derivatives and different azide sources were investigated and especially Uyanik’s and Ishihara’s recent approach using NaN3 in combination with the carefully designed achiral catalyst C1 represents a

• ammonium iodides [40]. Interestingly, designer catalyst C1 was found being catalytically superior compared to Bu4NI (TBAI) when using H2O2 as the oxidant. Furthermore, it turned out that addition of PBN (phenyl N-tert-butylnitrone) has a beneficial effect on the reaction and that carefully buffered

• α-S(e)CN-functionalization of different pronucleophiles [39] as well as the benzylic azidation of alkylphenol derivatives with NaN3 using TBAI as a catalyst [41]. Considering the fact that TBAI clearly represents one of the most easily available quaternary ammonium iodides and keeping in mind our

Towards an asymmetric β-selective addition of azlactones to allenoates

• Behzad Nasiri,
• Ghaffar Pasdar,
• Paul Zebrowski,
• Katharina Röser,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

• studies we also realized that the masked β-AA derivatives 2 undergo enantioselective β-addition to allenoates 3 under chiral ammonium salt catalysis (Scheme 1B) [18]. Interestingly, hereby we also found that the use of alternative catalyst systems (i.e., tertiary phosphines) allows for a γ-selective

• addition of 2 to the allenoate instead, thus resulting in two complementary catalyst-controlled pathways [18]. Based on these previous results, and also the well-documented different reactivity trends of allenoates 3 when using different organocatalysts and activation modes [23][24][25][26][27], we were

• (Table 1, entry 7, similar non-selective results were obtained when using THF), were found to be less-suited however. Testing the 3,4,5-trifluorobenzene-decorated catalyst B2 with K2CO3 in toluene next (Table 1, entry 8) allowed for a slightly higher selectivity but still gave only a relatively low yield

Electrophotochemical metal-catalyzed synthesis of alkylnitriles from simple aliphatic carboxylic acids

• Yukang Wang,
• Yan Yao and
• Niankai Fu

Beilstein J. Org. Chem. 2024, 20, 1497–1503, doi:10.3762/bjoc.20.133

• , the corresponding alkylnitrile product was obtained in 86% yield after electrolysis at 3.0 mA for 4 hours, demonstrating the high Faradaic efficiency of the reaction (Table 1, entry 5) [46]. Control experiments revealed that Ce catalyst, Cu catalyst, light, and electricity were all essential for the

• success of this transformation (Table 1, entries 6–9). We also tested other photoredox catalysts that are capable of driving the oxidative decarboxylation, only Fukuzumi catalyst [47] was able to deliver the product with a meaningful yield (Table 1, entry 10). The scope of this transformation was next

Synthesis of 2-benzyl N-substituted anilines via imine condensation–isoaromatization of (E)-2-arylidene-3-cyclohexenones and primary amines

• Lu Li,
• Na Li,
• Xiao-Tian Mo,
• Ming-Wei Yuan,
• Lin Jiang and
• Ming-Long Yuan

Beilstein J. Org. Chem. 2024, 20, 1468–1475, doi:10.3762/bjoc.20.130

• Lu Li Na Li Xiao-Tian Mo Ming-Wei Yuan Lin Jiang Ming-Long Yuan National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials; School of Chemistry and Environment, Yunnan Minzu University, Kunming, China 10.3762/bjoc.20.130 Abstract A catalyst- and

• Morita–Baylis–Hillman (MBH) adducts [20][21], we were interested in further utilizing (E)-2-arylidene-3-cyclohexenones that can be facilely synthesized from MBH alcohols to build functionalized molecules. Herein, we wish to report our preliminary study on a catalyst- and additive-free synthesis of 2

• -substituted anilines from (E)-2-arylidene-3-cyclohexenones and primary aliphatic amines. The reaction proceeds through an imine condensation–isoaromatization approach under catalyst- and additive-free conditions, allowing the generation of synthetically useful aniline derivatives in 23–82% yields. This method

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl₂ and NH₄SCN/KSeCN

• Jialiang Wu,
• Haofeng Shi,
• Xuemin Li,
• Jiaxin He,
• Chen Zhang,
• Fengxia Sun and
• Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

• presented a method for the C–H thiocyanation of pyrazoles by using a sustainable catalyst of graphite-phase carbon nitride (g-C3N4) under visible light irradiation (Scheme 1c) [2]. Furthermore, Yao harnessed an electrochemical approach to form the electrophilic SCN+ intermediate, which reacted with

Rapid construction of tricyclic tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine via isocyanide-based multicomponent reaction

• Xiu-Yu Chen,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2024, 20, 1436–1443, doi:10.3762/bjoc.20.126

• )-pentacarboxylates was developed by a three-component reaction. In the absence of any catalyst, the three-component reaction of alkyl isocyanides, dialkyl but-2-ynedioates and 5,6-unsubstituted 1,4-dihydropyridines in refluxing acetonitrile afforded polyfunctionalized tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine

• hour. In the presence of DABCO as base catalyst, the yield of 4a decreased to 27% (Table 1, entry 16). Other common bases such as Et3N and DMAP were also employed in the reaction, they did no gave the product 4a in higher yields than that in the absence of any base, which showed that the reaction does

A comparison of structure, bonding and non-covalent interactions of aryl halide and diarylhalonium halogen-bond donors

• Nicole Javaly,
• Theresa M. McCormick and
• David R. Stuart

Beilstein J. Org. Chem. 2024, 20, 1428–1435, doi:10.3762/bjoc.20.125

• possibly due to greater dispersive and lesser repulsive forces for larger halogens. This finding may prove useful in catalyst design where close spatial proximity of the substrate to other important structural information (i.e., chirality) has an impact on selectivity. Our analysis of selected XB complexes

Challenge N- versus O-six-membered annulation: FeCl₃-catalyzed synthesis of heterocyclic N,O-aminals

• Giacomo Mari,
• Lucia De Crescentini,
• Gianfranco Favi,
• Fabio Mantellini,
• Diego Olivieri and
• Stefania Santeusanio

Beilstein J. Org. Chem. 2024, 20, 1412–1420, doi:10.3762/bjoc.20.123

• of a high water amount results in catalyst deactivation. Based on these results and what was observed in the optimization tests (Table 1, entry 6), we extended the reaction time but used ACN as solvent, which possesses a higher water content with respect to DCM (experiment C, Scheme 5). Gratifyingly

Hypervalent iodine-catalyzed amide and alkene coupling enabled by lithium salt activation

• Akanksha Chhikara,
• Fan Wu,
• Navdeep Kaur,
• Prabagar Baskaran,
• Alex M. Nguyen,
• Zhichang Yin,
• Anthony H. Pham and
• Wei Li

Beilstein J. Org. Chem. 2024, 20, 1405–1411, doi:10.3762/bjoc.20.122

• simple lithium salts for hypervalent iodine catalyst activation. The activated hypervalent iodine catalyst allows the intermolecular coupling of soft nucleophiles such as amides onto electronically activated olefins with high regioselectivity. Keywords: amide coupling; hypervalent iodine catalysis

• ]. Notably, an interesting work by Hashimoto has recently enabled the intermolecular addition of N-(fluorosulfonyl)-protected carbamates as oxyamination reagents across a variety of olefin structures [47]. This work engages the hypervalent iodine catalyst in an anionic ligand exchange with the substrate

• , which then partitions into an ion pair suitable for olefin activation, followed by the addition of the bifunctional anionic carbamate (Scheme 1c). Our hypothesis here aims to directly access the reactivity of the cationic hypervalent iodine catalyst through an initial activation first, which we reason

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• potentially useful molecules. Keywords: Cannizzaro reaction; crossed-Cannizzaro; desymmetrization; Lewis acid catalyst; natural products; Introduction The synthesis of functionalized molecules with structural complexity has always been a challenge to synthetic chemists. The Cannizzaro reaction, in its

• in subsequent reactions. Reddy and coworkers carried out the Cannizzaro reaction of aromatic aldehydes to the corresponding alcohols in high yields by crossed-Cannizzaro reactions employing solid-supported KF-Al2O3 as catalyst [26] under microwave irradiation using solvent-free conditions. The use of

• -transfer catalyst in the presence of KOH as the base. Canipelle et al. [28] put forward an improved Cannizzaro disproportionation of 4-biphenylcarboxaldehyde into the corresponding alcohol and carboxylic acid products employing cyclodextrins as the phase-transfer agent. A Cannizzaro desymmetrization

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

• Mithu Roy,
• Bitan Sardar,
• Itu Mallick and
• Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

• , such as iridium complexes or organic dyes, and activating agents, including dimethyl dicarbonate (DMDC) and PPh3. Redox-active esters are created when activating agents and carboxylic acids react. These esters can then be reduced using a photoredox catalyst to produce the acyl radical. In 2019, Doyle

• catalyst is first excited and then transfers one electron to the thiocarbamate moiety to form a thiocarbamate radical anion, with change in oxidation state from III to IV. Next, the sacrificial electron donor Hünig base successfully converts [Ir(IV)] to [Ir(III)], with concurrent formation of an amine

• )], regenerating the [Ir(III)] catalyst and completing the catalytic cycle. Overman and co-workers [50] used tert-alkyl N-phthalimidoyl oxalates to produce alkyl radicals that were further reacted with various Michael acceptors (Scheme 13). The photocatalyst Ru(bpy)32+ and Hantzsch ester were essential for the

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

• for integrins which is critical for several diseases. Keywords: biphenyltetracarboxylic acid; homo-coupling; integrin inhibitor; rhodium catalyst; Ullmann-type reaction; Introduction The Ullmann reaction is a coupling reaction of aryl halides using copper, traditionally using metallic copper-bronze

• reaction mixture (Table 1, entry 10). Next, we investigated various Rh catalysts and solvents, and the results are summarized in Table 2. All Rh catalysts that were examined in this reaction gave the product in good yields, although in the absence of a Rh catalyst the reaction failed as shown in Table 2

• , entries 1–8. In addition, there was no need to prolong the reaction time (entry 3 in Table 2). Therefore, a Rh catalyst is essential in this reaction, and RhCl(PPh3)3 was chosen as the best catalyst because of its availability. In the examination of the reaction solvents, the use of THF led to the highest

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

• high regioselectivity. Herein, we report the electroreductive hydroarylation of electron-deficient alkenes and styrene derivatives using (hetero)aryl halides under mild reaction conditions. Notably, the present hydroarylation proceeded with high efficiency under transition-metal-catalyst-free

• by preventing overreduction [39]. While the metal-catalyst-free radical cyclization of alkene-tethered aryl halides has been well documented in the literature [40][41][42][43], the efficient intermolecular hydroarylation of alkenes still relies on the use of transition-metal catalysts, including Pd

• [44], Ni [45], and Co [46] (Scheme 1a). The pioneering work by Savéant et al. demonstrated that electron-deficient (hetero)aromatics acted as efficient mediators for the metal-catalyst-free electroreductive hydroarylation of alkenes with some activated chloro-, bromo-, and iodoarenes, but the use of a

Phenotellurazine redox catalysts: elements of design for radical cross-dehydrogenative coupling reactions

• Alina Paffen,
• Christopher Cremer and
• Frederic W. Patureau

Beilstein J. Org. Chem. 2024, 20, 1292–1297, doi:10.3762/bjoc.20.112

• enabling the activation of small yet highly relevant organic substrates. For example, Huber and co-authors recently designed a Te-based catalyst in an indole Michael addition reaction [1][2][3][4][5]. Pale and Mamane utilized another Te-based catalyst in an electrophilic bromine-mediated cyclization

• simple oxygen atmosphere (Scheme 1a) [30][31][32]. Most recently, we also showed that phenotellurazines could catalyze the oxidative dimerization of indoles, likewise under a simple oxygen atmosphere. 2-Methoxyphenotellurazine PTeZ2 proved to be the optimal catalyst in the latter case (Scheme 1b) [33

• ]. In the present study, we decided to revisit the design of the phenotellurazine redox catalyst, in the hope of improving it as well as enabling new catalytic reactivity. In particular, we wished to investigate and optimize the level of electronic cooperativity between the Te- and N-centers, the effect

Oxidative hydrolysis of aliphatic bromoalkenes: scope study and reactivity insights

• Amol P. Jadhav and
• Claude Y. Legault

Beilstein J. Org. Chem. 2024, 20, 1286–1291, doi:10.3762/bjoc.20.111

• by stoichiometric use of HTIB. Attempt to perform the reaction using a catalytic amount of 2-iodobenzoic acid (0.2) under similar oxidizing conditions resulted in slightly diminished yield for the desired α-bromoketone (Table 2, entry 2). Notably, the direct use of HTIB as the catalyst, with a

• the iodonium intermediate C. Liberation of PhI serves as the driving force for subsequent SN2 attack by the bromide anion to give the dialkyl α-bromoketone 2. m-CPBA then regenerates the hypervalent iodine (HTIB) catalyst by oxidizing PhI in the presence of TsOH·H2O. The formation of the Ritter-type

Synthesis and optical properties of bis- and tris-alkynyl-2-trifluoromethylquinolines

• Stefan Jopp,
• Franziska Spruner von Mertz,
• Peter Ehlers,
• Alexander Villinger and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1246–1255, doi:10.3762/bjoc.20.107

• bromide gave 4. With quinoline 4 in hand, we studied palladium-catalysed Sonogashira reactions with phenylacetylene (5a). Gratifyingly, our initial test reaction, using Pd(OAc)2 as catalyst with XPhos as ligand, gave bis-alkynylated product 6a in quantitative yield. Reducing the catalyst loading from 5 to

• 2.5 mol % or switching to more simple Pd(PPh3)4 still achieved quantitative yields. Less catalyst led to a reduced yield (Table 1). Consequently, we chose 2.5 mol % Pd(PPh3)4 for all further reactions. As a next step, we analysed the scope of our methodology (Scheme 2). The optimized conditions allow

Mechanistic investigations of polyaza[7]helicene in photoredox and energy transfer catalysis

• Johannes Rocker,
• Till J. B. Zähringer,
• Matthias Schmitz,
• Till Opatz and
• Christoph Kerzig

Beilstein J. Org. Chem. 2024, 20, 1236–1245, doi:10.3762/bjoc.20.106

• thorough photochemical characterization is essential for efficient light-driven applications. In this article, the mode of action of a polyazahelicene catalyst (Aza-H) was investigated using laser flash photolysis (LFP). The study revealed that the chromophore can function as a singlet-state photoredox

• catalyst in the sulfonylation/arylation of styrenes and as a triplet sensitizer in energy transfer catalysis. The singlet lifetime is sufficiently long to exploit the exceptional excited state reduction potential for the activation of 4-cyanopyridine. Photoinduced electron transfer generating the radical

• with a quantum yield of 0.34. The pronounced triplet formation was exploited for the isomerization reaction of (E)-stilbene to the Z-isomer and the cyclization of cinnamyl chloride. Catalyst degradation mainly occurs through the long-lived Aza-H triplet (28 µs), but the photostability is greatly

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• mechanism for the formation of oxamide is shown in Scheme 6. Formation of acetanilide in the reaction of aniline and acetonitrile is known to occur in the presence of Lewis acid catalyst Al2O3 [55]. In our case, either SeO2 (Lewis acid) or H2SeO3 (Brønsted acid) may act as acid catalyst to convert aniline

The Ugi4CR as effective tool to access promising anticancer isatin-based α-acetamide carboxamide oxindole hybrids

• Carolina S. Marques,
• Aday González-Bakker and
• José M. Padrón

Beilstein J. Org. Chem. 2024, 20, 1213–1220, doi:10.3762/bjoc.20.104

• using 5-amino-1-benzyl-3,3-dimethoxyindolin-2-one (1) [12] and benzyl isocyanide (4), as amine and isocyanide components, respectively. Different carboxylic acids 2 and aldehydes/ketones 3 were evaluated using ZnF2 as catalyst (10 mol %) and MeOH as the solvent (Scheme 2 and Figure 2). A library of α

• into the scaffold. Benzyl azide (6), obtained using a previously reported procedure [27], was used in the CuAAC reaction. The α-acetamide carboxamide 1,2,3-triazole oxindole hybrid 7 was easily obtained in 61% yield using Cu(OAc)2 as catalyst, ascorbic acid, DMF as solvent, and microwave reaction

Introduction of peripheral nitrogen atoms to cyclo-meta-phenylenes

• Koki Ikemoto and
• Hiroyuki Isobe

Beilstein J. Org. Chem. 2024, 20, 1207–1212, doi:10.3762/bjoc.20.103

• -doped [n]CMPs, 3a and 3b, were synthesized via one-pot Suzuki–Miyaura coupling [12] (Scheme 1). Previously, we synthesized [n]CMPs with inward-focused nitrogen dopants by using Suzuki–Miyaura coupling with Pd(PPh3)4 as the catalyst [13] and applied this method to outward-radiated congeners in this work

Bismuth(III) triflate: an economical and environmentally friendly catalyst for the Nazarov reaction

• Manoel T. Rodrigues Jr.,
• Aline S. B. de Oliveira,
• Ralph C. Gomes,
• Amanda Soares Hirata,
• Lucas A. Zeoly,
• Hugo Santos,
• João Arantes,
• Catarina Sofia Mateus Reis-Silva,
• João Agostinho Machado-Neto,
• Leticia Veras Costa-Lotufo and
• Fernando Coelho

Beilstein J. Org. Chem. 2024, 20, 1167–1178, doi:10.3762/bjoc.20.99

• , 13083-970 Campinas, São Paulo, Brazil Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, 05508-000 São Paulo, Brazil 10.3762/bjoc.20.99 Abstract We describe the use of bismuth(III) triflate as an efficient and environmentally friendly catalyst for the Nazarov

• the Nazarov reaction, using models already studied in the literature [33][34][35][36][37][38][39][40][41][42][43]. We investigated several conditions, such as the type of catalyst, temperature, solvent, and amount of catalyst (Table 1). Our optimization studies began with the reaction of substrate 9aa

• ). Once the catalyst was chosen, we investigated the influence of the solvent. For this purpose, we evaluated dichloroethane (DCE), dichloromethane (DCM), toluene, and tetrahydrofuran (THF) as solvents for the transformation (Table 1, entries 16–19), but acetonitrile remained the best solvent. Finally, we

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

• compounds. To achieve the selective C–C and C–N bond formation via hydrogen borrowing, controlling the selectivity is an important factor since the formation of possible side-products such as overreduction of unsaturated compounds or dialkylation. Hence, developing an efficient catalyst, capable of

• -methylation of amines with methanol was achieved with lower catalyst and base loading. Sortais et al. reported an elegant example of a manganese-catalyzed N-methylation of primary amines with methanol using catalytic amounts of base. They synthesized a novel Mn(I) complex bearing a bis(diaminopyridine

• synthesis of amines and imines using Mn-pincer catalyst [37]. When t-BuOK (1 equiv) was used as a base, alkylated amine products were observed selectively using alcohol as an alkylating agent, whereas when t-BuONa (1.5 equiv) was used as base, alkylated imine products were isolated (Scheme 6). This