Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• cleavage of the methoxyphenyl group in aqueous methanol using excess of ceric ammonium nitrate (CAN) as a soft oxidant (Scheme 14). The sequence afforded the target (S)-homoallylic amine 69 in 64% overall yield with a complete retention of chirality. To gain a mechanistic insight into the formation of the

O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization

• Kateryna V. Dil and
• Vitalii A. Palchykov

Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184

• (Table 1, entry 7). Reflux in alcoholic media in the presence of p-toluenesulfonic acid or CAN (ceric ammonium nitrate) was also not particularly successful (Table 1, entries 8 and 9, yield 32–35%). We subsequently explored a range of reaction conditions to improve overall yield and selectivity. We

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

• exo Diels–Alder cycloaddition, which resulted in compound 159. The enol ether was oxidized by ceric ammonium nitrate (CAN) to deliver intermediate 160, which was further subjected to an iron-catalyzed hydrogen atom transfer generating tricyclic intermediate 161. Further functionalization permitted the

Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

• Ilya A. P. Jourjine,
• Lukas Zeisel,
• Jürgen Krauß and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2668–2679, doi:10.3762/bjoc.17.181

• secondary and tertiary amines, amides/lactams/carbamates, and nitrile. The test reactions were monitored by thin-layer chromatography (TLC) and, where deemed necessary, results were further verified by GC–MS. The reagents employed encompassed tritylium tetrafluoroborate [50], H2O2/HBr [42], ceric ammonium

• nitrate (CAN) [41], 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO)/CuCl [51], K2S2O8 [36], dimethyl sulfoxide (DMSO)/O2 [52], PhI(OAc)2/benzoyl peroxide (BPO) [47], Dess-Martin periodinane, N-bromosuccinimide (NBS), N-hydroxyphthalimide (NHPI)/Co(OAc)2/O2 [53], H2O2/tetrabutylammonium iodide (TBAI) [43], CBr4

Synthesis of phenanthridines via a novel photochemically-mediated cyclization and application to the synthesis of triphaeridine

• Songeziwe Ntsimango,
• Kennedy J. Ngwira,
• Moira L. Bode and
• Charles B. de Koning

Beilstein J. Org. Chem. 2021, 17, 2340–2347, doi:10.3762/bjoc.17.152

• Information File 1. Trisphaeridine (3) To a solution of 2,3-dimethoxy-[1,3]dioxolo[4,5-j]phenanthridine (23, 63 mg, 0.22 mmol) in acetonitrile (3 mL) was slowly added a solution of ceric ammonium nitrate (356 mg, 0.65 mmol) in water (1.5 mL) at 0 °C. The resulting solution was stirred at the same temperature

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

• -headed nucleosides 151a–d starting from LNA uridine diol 147 which in turn was synthesized from diacetone-α-ᴅ-allose following a procedure reported in the literature [76]. LNA uridine diol 147 was reacted with iodine and ceric ammonium nitrate (CAN) in acetic acid to afford the nucleoside 148. Nucleoside

Photocatalytic deaminative benzylation and alkylation of tetrahydroisoquinolines with N-alkylpyrydinium salts

• David Schönbauer,
• Carlo Sambiagio,
• Timothy Noël and
• Michael Schnürch

Beilstein J. Org. Chem. 2020, 16, 809–817, doi:10.3762/bjoc.16.74

• these compounds are either free amines or N-alkylated [48][49]. Hence, we tested the oxidative cleavage of the PMP group of compound 24 (Scheme 4), with ceric ammonium nitrate (CAN) [50][51]. After column chromatography, 50% of the desired free amine were isolated, which made this method a viable route

Asymmetric synthesis of CF₂-functionalized aziridines by combined strong Brønsted acid catalysis

• Xing-Fa Tan,
• Fa-Guang Zhang and
• Jun-An Ma

Beilstein J. Org. Chem. 2020, 16, 638–644, doi:10.3762/bjoc.16.60

• chiral centers, pointing at a cis-aziridination process [46]. Scaled-up experiments with model substrate 1a also proved to be feasible, delivering the chiral CF2-aziridine 4a with comparable results (Scheme 3a). The 4-methoxyphenyl group of 4a was cleaved smoothly with ceric ammonium nitrate, giving the

Synthesis of the polyketide section of seragamide A and related cyclodepsipeptides via Negishi cross coupling

• Jan Hendrik Lang and
• Thomas Lindel

Beilstein J. Org. Chem. 2019, 15, 577–583, doi:10.3762/bjoc.15.53

• separate the diastereomers of product 13 by column chromatography. The use of DMEAD (di-2-methoxyethyl azodicarboxylate) [38] was inferior (33%). The PMP protecting group was envisioned to be stable during the following steps and to be selectively cleavable with ceric ammonium nitrate (CAN). Reduction of

Synthesis of a leopolic acid-inspired tetramic acid with antimicrobial activity against multidrug-resistant bacteria

• Luce Mattio,
• Loana Musso,
• Leonardo Scaglioni,
• Andrea Pinto,
• Piera Anna Martino and
• Sabrina Dallavalle

Beilstein J. Org. Chem. 2018, 14, 2482–2487, doi:10.3762/bjoc.14.224

• ester nitrogen we chose the p-methoxybenzyl (PMB) group, easily removable by ceric ammonium nitrate (CAN). N-(4-Methoxybenzyl)glycine ethyl ester (5) was obtained in 87% yield by reacting 4-methoxybenzylamine (3) with bromoacetic acid ethyl ester (4) in THF (Scheme 1). The ester 5 was converted into

• and the formation of an enolate, which was subsequently reacted with 1-iododecane and deprotected with ceric ammonium nitrate to afford derivatives 8a and 8b, respectively. Unfortunately, at this stage all attempts to decarboxylate compounds 8a and 8b failed [22]. To overcome the problem of

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• Hantzsch pyrrole synthesis is well known for the construction of poly substituted pyrroles [121][122]. In 1998, Jung and co-workers reported polymer supported solid phase synthesis of N-substituted pyrroles [123]. In 2013, Menendez and co-workers reported a ceric ammonium nitrate (CAN) and silver-nitrate

Synthesis of the C8’-epimeric thymine pyranosyl amino acid core of amipurimycin

• Pramod R. Markad,
• Navanath Kumbhar and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2016, 12, 1765–1771, doi:10.3762/bjoc.12.165

• reduction of the azide to an amine) affording a crude product which was directly reacted with CbzCl to afford compound 19 (Scheme 5). Compound 19 on reaction with ceric ammonium nitrate (deprotection of PMP ether) followed by acetyl protection of the resultant triol using Ac2O in pyridine gave triacetate

Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

• Louis P. Sandjo,
• Victor Kuete and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2015, 11, 1667–1699, doi:10.3762/bjoc.11.183

• the yield of 12 was greater in the second preparation. Nevertheless, the red color mentioned for neoamphimedine after route B seems unusual. The natural product is known as a yellow solid [61] suggesting that the neamphimedine in this case might be contaminated with ceric ammonium nitrate (CAN), which

Photovoltaic-driven organic electrosynthesis and efforts toward more sustainable oxidation reactions

• Bichlien H. Nguyen,
• Robert J. Perkins,
• Jake A. Smith and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2015, 11, 280–287, doi:10.3762/bjoc.11.32

• from the light-driven process is comparable to the literature value for the oxidation. The final oxidation in Scheme 4c illustrates the use of the light-driven electrolysis reaction for recycling ceric ammonium nitrate (CAN) for a p-methoxybenzyl deprotection of an alcohol proceeding through oxidation

Efficient carbon-Ferrier rearrangement on glycals mediated by ceric ammonium nitrate: Application to the synthesis of 2-deoxy-2-amino-C-glycoside

• Alafia A. Ansari,
• Y. Suman Reddy and
• Yashwant D. Vankar

Beilstein J. Org. Chem. 2014, 10, 300–306, doi:10.3762/bjoc.10.27

• Alafia A. Ansari Y. Suman Reddy Yashwant D. Vankar Department of Chemistry, Indian Institute of Technology Kanpur 208 016, India 10.3762/bjoc.10.27 Abstract A carbon-Ferrier rearrangement on glycals has been performed by using ceric ammonium nitrate to obtain products in moderate to good yields

• -glycosides; carbon-Ferrier rearrangement; ceric ammonium nitrate; 2-deoxy-2-aminoglycosides; Overman rearrangement; Introduction The growing significance of C-glycosides can be attributed to their potential use as inhibitors of carbohydrate-processing enzymes [1][2][3], their extraordinary stability

• reaction. In view of our continued interest in the development of novel methods for the synthesis of O- and C-glycosides [31][32][33][34][35][36], we here report on the carbon-Ferrier rearrangement of glycals by using ceric ammonium nitrate. Ceric ammonium nitrate (CAN) is a versatile and efficient reagent

Amyloid-β probes: Review of structure–activity and brain-kinetics relationships

• Todd J. Eckroat,
• Abdelrahman S. Mayhoub and
• Sylvie Garneau-Tsodikova

Beilstein J. Org. Chem. 2013, 9, 1012–1044, doi:10.3762/bjoc.9.116

• kinetics [47]. Representative syntheses of radioiodinated oxadiazoles 50a and 51c are shown (Scheme 5B and C). The 1,3,4-oxadiazole core of [125I]50a was obtained from the reaction between 4-iodobenzhydrazide (52) and 4-dimethylaminobenzaldehyde (23) in the presence of ceric ammonium nitrate (CAN) followed

Synthesis of phenanthridines via palladium-catalyzed picolinamide-directed sequential C–H functionalization

• Ryan Pearson,
• Shuyu Zhang,
• Gang He,
• Nicola Edwards and
• Gong Chen

Beilstein J. Org. Chem. 2013, 9, 891–899, doi:10.3762/bjoc.9.102

• cyclization and oxidation steps can be performed in one step to give the phenanthridines in a shorter procedure. A variety of oxidants, such as 1,4-benzoquinone (BQ), KMnO4, ceric ammonium nitrate (CAN), and copper salts were examined [46]. The combination of PhI(OAc)2 (2 equiv) and Cu(OAc)2 (2 equiv

Multicomponent reaction access to complex quinolines via oxidation of the Povarov adducts

• Esther Vicente-García,
• Rosario Ramón,
• Sara Preciado and
• Rodolfo Lavilla

Beilstein J. Org. Chem. 2011, 7, 980–987, doi:10.3762/bjoc.7.110

• aromatic species. The literature contains scattered reports of the use of oxidants for this transformation: 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), ceric ammonium nitrate (CAN), nitrobenzene, elemental sulfur, palladium and manganese dioxide among others, all of them far from being ideally suited

Single enantiomer synthesis of α-(trifluoromethyl)-β-lactam

• Václav Jurčík,
• Alexandra M. Z. Slawin and
• David O'Hagan

Beilstein J. Org. Chem. 2011, 7, 759–766, doi:10.3762/bjoc.7.86

• is reported which took advantage of an aza-Michael addition between (S)-α-(p-methoxyphenyl)ethylamine (3b) and α-(trifluoromethyl)acrylic acid (2). Cyclisation and then chromatographic resolution of the β-lactam diastereoisomers 5b, followed by deprotection with ceric ammonium nitrate generated the β

• ), ceric ammonium nitrate (1.94 g, 3.54 mmol, 3 equiv) was added portionwise. The reaction mixture was stirred at RT for 16 h and then quenched with sat. sodium bicarbonate (5 mL). After 10 min of stirring (when gas evolution ceased), the mixture was extracted into Et2O (3 × 10 mL), the combined organic

• explored for the hydrogenolysis of 5a, however cleavage of the C–N bond proved very difficult and a satisfactory method could not be found. Therefore, (S)-α-(p-methoxyphenyl)ethylamine (3b) was explored as an alternative amine for the aza-Michael reaction, as removal of this amine using ceric ammonium

Synthesis, reactivity and biological activity of 5-alkoxymethyluracil analogues

• Lucie Brulikova and
• Jan Hlavac

Beilstein J. Org. Chem. 2011, 7, 678–698, doi:10.3762/bjoc.7.80

• -(2-chlorovinyl)-2'-deoxyuridine (89) and 5-(1-methoxy-2-chloroethyl)-2'-deoxyuridine (13). 5-Vinyl-2'-deoxyuridine (9) can also undergo reaction with ceric ammonium nitrate (CAN) and sodium azide in aqueous acetonitrile to give 5-(1-hydroxy-2-azidoethyl)-2'-deoxyuridine (92) in 32% yield. When dry

A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

• Magnus Rueping and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2010, 6, No. 6, doi:10.3762/bjoc.6.6

• reduction [121]. The same authors reported shortly after their initial finding a highly efficient substitution of ferrocenyl alcohols in water, without the need of any Lewis-acid catalyst [50]. A comparable, non-chiral version of this C–C bond forming reaction using ceric ammonium nitrate has recently been

Photosonochemical catalytic ring opening of α-epoxyketones

• Hamid R. Memarian and
• Ali Saffar-Teluri

Beilstein J. Org. Chem. 2007, 3, No. 2, doi:10.1186/1860-5397-3-2

• and α-epoxyketones have also occurred thermally or photochemically by the presence of various electron acceptors. These reactions have been observed thermally by ceric ammonium nitrate (CAN), [28][29] 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) [30] and iron(III) chloride [31] or photo-induced

Investigation of acetyl migrations in furanosides

• O. P. Chevallier and
• M. E. Migaud

Beilstein J. Org. Chem. 2006, 2, No. 14, doi:10.1186/1860-5397-2-14

• ) in THF, with KF in the presence of 18-crown-6 in benzene, with ceric ammonium nitrate IV (CAN) in aqueous acetonitrile and with H2-Pd/C in THF. No attempts were made to examine standard protic acid-catalysed desilylations such as AcOH in H2O/THF[16] or TFA/H2O in DCM[17] since we observed rapid