Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• review in 2018 focused on a variety of routes to these compounds [8]. The well-known Buchwald–Hartwig (B–H) and Chan–Lam (C–L) reactions have proven to be highly useful procedures that allow the step-economical synthesis of diverse biologically relevant heterocycles through C–N bond formation [9]. These

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• under heating, followed by the formation of ylide, N–S bond cleavage, and C–N bond formation along with the release of N2. In 2019, Sun and co-workers introduced an unprecedented method for the synthesis of isothiourea derivatives via the activation of diaryl/alkyl disulfides 47 with N-halosuccinimides

Copper-catalyzed N-arylation of amines with aryliodonium ylides in water

• Kasturi U. Nabar,
• Bhalchandra M. Bhanage and
• Sudam G. Dawande

Beilstein J. Org. Chem. 2023, 19, 1008–1014, doi:10.3762/bjoc.19.76

• electron-withdrawing groups on the aryl ring reacted smoothly with iodonium ylides to give the corresponding diarylamines with good to excellent yields. Also, secondary amines underwent N-arylation to deliver tertiary amines with moderate yields. Keywords: amines; arylation; C–N bond formation; iodonium

• strategies for C–N bond formation have been extensively explored by various research groups for the N-arylation of amines. Specifically, seminal contributions by Buchwald [15] and Hartwig [16] involving the use of palladium complexes as catalysts in the presence of either phosphine or diamine ligands for C–N

• bond formation. However, these methods suffer from limitations such as moisture sensitivity, the requirement of specific ligands, and the use of expensive palladium catalysts [17]. Also, Chan Lam, Evans, and other research groups have developed copper-catalyzed C–N bond formation reactions by careful

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90

• for the synthesis of 1,2-azaphospholidine 2-oxides/sulfides and their fused derivatives. The 1,2-azaphospholidine 2-oxide/sulfide derivatives have been prepared by construction of any of their ring bonds. Synthesis via C–N bond formation In 1962, Helferich and Curtius reported the first synthesis of a

• 1,2-azaphospholidine 2-oxide (γ-phosphonolactam) from N,N’-diphenyl 3-chloropropylphosphondiamide (1), which was cyclized to 1-phenyl-2-phenylamino-γ-phosphonolactam (2) in the presence of NaOH in methanol via the C–N bond formation (Scheme 1) [21]. In 1974, the strategy was applied for the synthesis

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

• ). Enantioselectivity for a wide range of substrates was achieved in good yield with rigorous optimization of the reaction conditions by utilization of wild-type CAL-B. Synthetic N-glycosylation strategies for glycosidic C–N bond formation in 1,3-oxathiolane nucleosides This section will discuss the methods for

Visible-light-mediated copper photocatalysis for organic syntheses

• Yajing Zhang,
• Qian Wang,
• Zongsheng Yan,
• Donglai Ma and
• Yuguang Zheng

Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169

• extending this protocol from C–N bond formation reactions to C–O [85], C–S [86], and C–C [87][88] bond formations. Recently, a photoredox catalysis was applied to these types of cross-coupling reactions, with key contributions from the groups of Ackermann [87], Evano [55], Zhang [89], Nguyen [90], and

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

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• -alkenyloxindole 43 were considered to be the building blocks united in ethanol as solvent (Scheme 15). The notable highlights of the described methodology are diastereoselective C–C and C–N bond formation, high yields, non-toxic product, and cost-effectiveness along with a greener approach. The synthetic strategy

Amino- and polyaminophthalazin-1(2H)-ones: synthesis, coordination properties, and biological activity

• Zbigniew Malinowski,
• Emilia Fornal,
• Agata Sumara,
• Renata Kontek,
• Karol Bukowski,
• Beata Pasternak,
• Dariusz Sroczyński,
• Joachim Kusz,
• Magdalena Małecka and
• Monika Nowak

Beilstein J. Org. Chem. 2021, 17, 558–568, doi:10.3762/bjoc.17.50

• quinazolinones [30][31] and taking into consideration the biological importance of aminophthalazine derivatives, we decided to apply the methodology based on the palladium-catalyzed C–N-bond formation (Buchwald–Hartwig-type reaction) as a convenient and effective approach for the synthesis of the new

• course of the reaction and in several cases resulted in the formation of 2-methylphthalazin-1(2H)-one, i.e., the debromination product of bromophthalazinone 3a. The commonly adopted view on the mechanism of the Pd-mediated C–N-bond formation (Buchwald–Hartwig-type coupling) [37][38][39][40] assumes that

Deoxygenative C2-heteroarylation of quinoline N-oxides: facile access to α-triazolylquinolines

• Geetanjali S. Sontakke,
• Rahul K. Shukla and
• Chandra M. R. Volla

Beilstein J. Org. Chem. 2021, 17, 485–493, doi:10.3762/bjoc.17.42

• significant interest in the last few years [12][13]. In particular, the C2-functionalization of quinolines has been well studied, and various methodologies were established for C–C [14][15][16][17][18][19][20][21][22][23], C–O [24][25] and C–S [26][27] bond formation. Recently C2-selective C–N bond formation

• purified by column chromatography (ethyl acetate/petroleum ether 1:9) to get the desired product 3a in 92% yield (50 mg, 0.18 mmol). Bioactive molecules containing the 2-aminoquinoline motif. C2-selective C–N bond formation of N-oxides. Substrate scope of N-sulfonyl-1,2,3-triazoles. Reaction conditions: 1a

Syntheses of spliceostatins and thailanstatins: a review

• William A. Donaldson

Beilstein J. Org. Chem. 2020, 16, 1991–2006, doi:10.3762/bjoc.16.166

• endpoint. However, Nicolaou’s route is the shortest (6 or 7 steps, 9.8–9.2% yield), while Kitahara’s synthesis is the highest-yielding and does not involve the use of expensive transition metals or organocatalysts. Syntheses to generate the C-14 stereocenter via C–N bond formation Two groups implemented

• strategies that rely on the generation of the C-14 stereocenter by stereoselective C–N bond formation. The Jacobsen group utilized an asymmetric Cr(III)-catalyzed cycloaddition reaction [27] between (2Z,4E)-3-(triethylsilyloxy)-2,4-hexadiene (40) and the aldehyde 41 to generate the 4-silyloxydihydropyran 43

Photocatalyzed syntheses of phenanthrenes and their aza-analogues. A review

• Alessandra Del Tito,
• Havall Othman Abdulla,
• Davide Ravelli,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123

• formed by an intramolecular C–C or C–N bond-formation event, as detailed in the following. 2.1 Synthesis of phenanthridines via photocatalyzed intramolecular C–C bond formation A typical approach makes use of imidoyl radicals [30][44] as the key intermediates. Among the different methods proposed to

• proximity to each other, prone to be engaged in a bidentate-type metal-coordination complex [75]. 2.2 Synthesis of phenanthridines via photocatalyzed C–N bond formation As mentioned in the introduction, the examples gathered here involve the intermediacy of N-centered radicals. As a representative case, the

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

• rule, a C–O bond is formed in intermolecular reactions, intramolecular cyclization generally occurs with the formation of a five-membered cycle of isoxazoline (C–O bond formation) or nitrone (C–N bond formation). Application of the oxime radicals in organic synthesis: intermolecular reactions Selective

Copper catalysis with redox-active ligands

• Agnideep Das,
• Yufeng Ren,
• Cheriehan Hessin and
• Marine Desage-El Murr

Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77

• selectivity. Homo- and cross-coupling adducts 16a and 16b–g were obtained from the corresponding phenols (14a–e and 15a–c) as shown in the bottom of Scheme 9 with high chemoselectivity. C–N bond formation While copper complexes are at the heart of oxidative biological networks, the introduction of nitrogen is

• metalloenzymatic active site was not characterized in detail, it might bear some resemblance to the original biological active site. Building on their previously discussed phenol oxidation methodology (Scheme 5 and Scheme 6), Lumb and co-workers have targeted subsequent C–N bond formation to access oxindoles [34

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• = Cu/Au molar ratio, Gx = dendrimer generation, and AAA = dendron type). After the preparation and characterization of the CuYAu–Gx-AAA–SBA-15 catalyst, the material was employed in a triazole synthesis, and it was established that the catalyst was efficient in the Sharpless–Meldal C–N bond formation

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• chlorodiphenylphosphine, afforded 1-methyl-4,5-bis(diphenylphosphino)imidazole (85). Finally, N-methylation gave the imidazolium salt derivative 86 in good yield (65%). Preparation of N-heterocyclic phosphines via metal-catalyzed P–C/N bond formation There is limited availability of certain N-containing precursors and

Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids

• László Orha,
• József M. Tukacs,
• László Kollár and
• László T. Mika

Beilstein J. Org. Chem. 2019, 15, 2907–2913, doi:10.3762/bjoc.15.284

• iodide (Table 3, entries 2–7). Under identical conditions, 2-iodothiophene, and iodopyridine derivatives could also easily be converted to the corresponding acetylene with good or even excellent isolated yields (3i–n). When 2-amino-3-iodopyridine (1i) was converted no C–N bond formation was detected

A metal-free approach for the synthesis of amides/esters with pyridinium salts of phenacyl bromides via oxidative C–C bond cleavage

• Kesari Lakshmi Manasa,
• Yellaiah Tangella,
• Namballa Hari Krishna and
• Mallika Alvala

Beilstein J. Org. Chem. 2019, 15, 1864–1871, doi:10.3762/bjoc.15.182

• new C–N bonds in the presence of transition metal catalysts [25][26][27][28][29][30][31][32][33][34]. Tang and Jiao reported copper catalyzed C–C single bond cleavage and C–N bond formation [35]. However, the transition metal catalysts and additives employed in these transformations are toxic and

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• aromatic or aliphatic, only in case of triazoles substituted with an acetate group the final product was obtained in 66% yield. An open-flask, one-pot, Cu(II)-catalyzed ligand-free approach towards C–N bond formation was reported by Rasheed et al. [116]. The reaction was catalyzed by Cu(OAc)2 with cesium

• mechanisms, i.e., a Chan–Lam coupling and an Ullmann coupling. The Chan–Lam coupling involved a C–N bond formation (intermediate I, 84) which then entered into the Ullmann coupling to undergo intramolecular cyclization to form final product 78 and release Cu(III) to Cu(I) by reductive elimination. In this

• and EDGs were also well tolerated by pyridinium ylides. The group of Bharate and Abbat have successfully reported a simple, efficient and excellent C–N bond formation catalyzed by CuBr [124]. The protocol involved the aerobic oxidative coupling of 2-APs with cinnamaldehyde to form 3-formyl-2

An efficient and concise access to 2-amino-4H-benzothiopyran-4-one derivatives

• Peng Li,
• Yongqi Wu,
• Tingting Zhang,
• Chen Ma,
• Ziyun Lin,
• Gang Li and
• Haihong Huang

Beilstein J. Org. Chem. 2019, 15, 703–709, doi:10.3762/bjoc.15.65

• process. The direct C–N bond formation reaction at the 2-position smoothly took place using ethylsulfinyl as the optimal leaving group and various nucleophiles such as aliphatic and aromatic amines. A variety of 2-aminobenzothiopyranones were obtained in moderate to excellent yields without the assistance

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• molecules. An interesting report of C–N bond formation is seen in König and co-workers’ method for the formation of sulfonamidated pyrroles, using acridinium salts as photocatalysts, in the presence of oxygen and sodium hydroxide (Scheme 10) [53]. Unfortunately, this protocol was investigated for its use in

Glycosylation reactions mediated by hypervalent iodine: application to the synthesis of nucleosides and carbohydrates

• Yuichi Yoshimura,
• Hideaki Wakamatsu,
• Yoshihiro Natori,
• Yukako Saito and
• Noriaki Minakawa

Beilstein J. Org. Chem. 2018, 14, 1595–1618, doi:10.3762/bjoc.14.137

• have been widely used in organic synthesis [38]. Although originally used as oxidative agents, their use has spread to coupling reactions, including those for the formation of C–C bonds [39][40][41][42][43]. In the case of C–N bond formation, introduction of an azido group using PhI=O and TMSN3 was

• developed. Since the Friedel–Crafts type reaction involved carbocation intermediate, the reaction always gave a mixture of products. Unfortunately, the reaction was not efficient. However, it is worthy that the oxidative coupling reaction contains a novel type of C–N bond formation and would help to

• -mediated glycosylation led us to apply the reaction to the synthesis of carbocyclic nucleosides. In addition, we were also encouraged by the study of Ochiai, who developed the Friedel–Crafts reaction via umpolung of allylsilanes using hypervalent-iodine reagents [61] and the pioneering work on C–N bond

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• has led to a much lower yield when compared to that obtained from the corresponding diaryl-λ3-iodane. In 2011, the group of Detert has reported the first example of a palladium-catalyzed double C–N bond formation starting from the cyclic (phenyl)(pyrido)-λ3-iodane 61 (Scheme 25) [65]. The reaction

[3 + 2]-Cycloaddition reaction of sydnones with alkynes

• Veronika Hladíková,
• Jiří Váňa and
• Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

• formation followed by Cu–N dissociation and C–N bond formation. Experiments performed in t-BuOD/D2O [119] also showed almost exclusive (>98:2) deuteration of position 3 in the final pyrazole ring. This finding supports the idea of Cu(I)-acetylide addition to give 3-metalated pyrazole (Cu-pyrazolide) that is