Trifluoromethylated hydrazones and acylhydrazones as potent nitrogen-containing fluorinated building blocks

• Zhang Dongxu

Beilstein J. Org. Chem. 2023, 19, 1741–1754, doi:10.3762/bjoc.19.127

• =N motif within hydrazones gives them both electrophilic and nucleophilic character. In 2005, Brigaud et al. developed a highly stereoselective method for the synthesis of α-trifluoromethylamines with organometallic reagents to extend the asymmetric methodologies of trifluoroacetaldehyde hydrazones

One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• the alkynyl-substituted 1,2-oxazin-4-ol derivative 19 which is smoothly available from the corresponding ketone 6 by highly stereoselective reduction with sodium borohydride [53]. Starting from 1,3- (8) or 1,4-bis(bromomethyl)benzene (16), respectively, the approved conditions in the presence of TBTA

Synthesis of medium and large phostams, phostones, and phostines

• Jiaxi Xu

Beilstein J. Org. Chem. 2023, 19, 687–699, doi:10.3762/bjoc.19.50

• construction of the rings. However, the synthetic methods are still limited, especially for asymmetric synthetic methods. Thus, it is clear that highly stereoselective asymmetric synthetic methods to access various medium and large phostam, phostone, and phostine derivatives are in high demand and should be

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• stereocenters were isolated in excellent yields and high diastereoselectivity. The authors have shown that catalyst loadings as low as 0.5 mol % can still be sufficient to promote the highly stereoselective reaction. Similarly to aldol reactions, Mannich-type additions are also suitable to trap the metal

• complex molecules by further transformations. Similarly, Huang et al. have recently published their work on the Rh-bod complex-catalyzed highly stereoselective tandem arylation/aldol cyclization [95]. The conjugate addition of arylboronic acids to acyclic α,β-unsaturated ketones 147 with sequential

•  56B) [103]. These complex natural compounds exhibit strong pharmacological activities like anti-inflammatory, antituberculosis, analgesic properties, etc. The key reaction steps included a highly stereoselective gold-catalyzed or thermally activated Cope rearrangement and a gold-catalyzed 6-endo-dig

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

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

• Bram Ryckaert,
• Ellen Demeyere,
• Frederick Degroote,
• Hilde Janssens and
• Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

• should be noted that the three-step strategy (dithiolane protection, oxidative rearrangement, and hydrodesulfurization) can be used to treat carbonyl functional groups as synthetic equivalents of cis-alkenes (Scheme 10c), as is shown by the highly stereoselective conversion of α-phenylacetophenone (60

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

• + 1] Annulations have been mainly utilized in the construction of the 1,2-azaphospholidine ring, while the [3 + 2] annulation has been seldomly used in the synthesis of pyridine-fused 1,2-azaphospholidine 2-oxide only. Few asymmetric synthetic methods have been developed to date. Thus, highly

• stereoselective asymmetric synthetic methods to access 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides, and their fused and spiro derivatives are in high demand and should be developed in the near future. Biologically active 1,2-azaphospholine 2-oxide derivatives. Diverse synthetic strategies for

BINOL as a chiral element in mechanically interlocked molecules

• Matthias Krajnc and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53

• ) [59]. The catenane catalyst allows for the asymmetric transfer hydrogenation of 2-substituted quinolines by Hantzsch esters in a highly stereoselective fashion [60]. It was found that the catenated catalyst gives superior stereoselectivities in comparison to the macrocyclic and the acyclic reference

Highly stereocontrolled total synthesis of racemic codonopsinol B through isoxazolidine-4,5-diol vinylation

• Lukáš Ďurina,
• Anna Ďurinová,
• František Trejtnar,
• Ľuboš Janotka,
• Lucia Messingerová,
• Jana Doháňošová,
• Ján Moncol and
• Róbert Fischer

Beilstein J. Org. Chem. 2021, 17, 2781–2786, doi:10.3762/bjoc.17.188

• homoallylic position that assists the electrophilic attack on the double bond [33][34]. The protection of the homoallylic hydroxy group in similar alkenyl diols in epoxidations with the VO(acac)2/t-BuOOH system led to the formation of the erythro isomer [35]. Actually, highly stereoselective epoxidations of

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

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

• study [41][42] in 2017. This metal-catalyzed, photoinduced, and asymmetric radical transformation requires two catalysts, namely, (i) a metal catalyst that promotes electron transfer and (ii) a separate chiral catalyst that facilitates the highly stereoselective bond formation. In 2016, Fu [82

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

Asymmetric organocatalyzed synthesis of coumarin derivatives

• Natália M. Moreira,
• Lorena S. R. Martelli and
• Arlene G. Corrêa

Beilstein J. Org. Chem. 2021, 17, 1952–1980, doi:10.3762/bjoc.17.128

• acid (4) as catalyst [30]. Based on this pioneer work, our research group described an efficient, highly stereoselective, one-pot process comprising an organocatalytic conjugate addition of dimedone or 4-hydroxycoumarin 1 to α,β-unsaturated aldehydes 2 followed by an intramolecular isocyanide-based

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

Stereoselective synthesis and transformation of pinane-based 2-amino-1,3-diols

• Ákos Bajtel,
• Mounir Raji,
• Matti Haukka,
• Ferenc Fülöp and
• Zsolt Szakonyi

Beilstein J. Org. Chem. 2021, 17, 983–990, doi:10.3762/bjoc.17.80

• carbamate 8 in good yield [27][28][36]. In the next step, the aminohydroxylation was accomplished by potassium osmate(VI) as the catalyst and t-BuOCl in the presence of DIPEA affording oxazolidine-2-one 9 [27]. The reaction was found to be highly stereoselective, giving exclusively the diexo-fused tricyclic

Prins cyclization-mediated stereoselective synthesis of tetrahydropyrans and dihydropyrans: an inspection of twenty years

• Asha Budakoti,
• Pradip Kumar Mondal,
• Prachi Verma and
• Jagadish Khamrai

Beilstein J. Org. Chem. 2021, 17, 932–963, doi:10.3762/bjoc.17.77

• cyclization and minimizes the competitive 2-oxonia-[3,3]-sigmatropic rearrangement pathway. The reaction was highly stereoselective and afforded the cis-2,6-dihydropyran in the presence of Lewis acid FeCl3. From DFT calculations, the authors concluded that the Prins product is formed more rapidly than the α

• (Scheme 60). Competition between electronically favored transition state 254 leads to the formation of anti-isomer 256, whereas the sterically preferred transition state 255 afforded syn-isomer 257. Unlike the well-explored selective synthesis of major cis-2,6-THP, a highly stereoselective route to the

Synthetic strategies of phosphonodepsipeptides

• Jiaxi Xu

Beilstein J. Org. Chem. 2021, 17, 461–484, doi:10.3762/bjoc.17.41

• phosphonodepsipeptides in the future. However, highly stereoselective asymmetric synthetic methods of phosphonodepsipeptides are of high demand and need to be developed in the near future. Phosphonopeptides, phosphonodepsipeptides, peptides, and depsipeptides. The diverse strategies for phosphonodepsipeptide synthesis

Au(III) complexes with tetradentate-cyclam-based ligands

• Ann Christin Reiersølmoen,
• Thomas N. Solvi and
• Anne Fiksdahl

Beilstein J. Org. Chem. 2021, 17, 186–192, doi:10.3762/bjoc.17.18

• trans product. Thus, the proper choice of the gold catalyst allows highly stereoselective formation of either cis or trans cyclopropanation products and facilitates the isolation of pure isomers. Despite the chiral nature of these ligands, no enantioselectivity was observed in the test reactions

Syntheses of spliceostatins and thailanstatins: a review

• William A. Donaldson

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

• highly stereoselective, this relatively lengthy route was somewhat inefficient (16 steps, 1.4% overall yield). The Nicolaou synthesis [24][25] of the C-1–C-9 tetrahydropyranyl segment commenced with the protected dihydropyranone 103 (Scheme 17), readily prepared from ᴅ-glucal [38]. The application of an

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• ) reacted with electron-poor olefins, such as acrylonitrile (187b), methyl acrylate (187c), and cis- and trans-1,2-dichloroethenes 188, under photochemical conditions, giving 2-silylthietanes 317 and 318 in a regio- and highly stereoselective manner. However, silyl thietanes without any regio- or

Distinctive reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under photoredox conditions

• Shrikant D. Tambe,
• Kwan Hong Min,
• Naeem Iqbal and
• Eun Jin Cho

Beilstein J. Org. Chem. 2020, 16, 1335–1342, doi:10.3762/bjoc.16.114

• electron density or position of the substituent on the benzylidene moiety. Interestingly, the homocoupling process was highly stereoselective, resulting in the formation of only one diastereomer, probably due to the bulky substitution pattern of the substrates. The structure of the homocoupled 1,2-diamine

Synthesis of 3-substituted isoxazolidin-4-ols using hydroboration–oxidation reactions of 4,5-unsubstituted 2,3-dihydroisoxazoles

• Lívia Dikošová,
• Júlia Laceková,
• Ondrej Záborský and
• Róbert Fischer

Beilstein J. Org. Chem. 2020, 16, 1313–1319, doi:10.3762/bjoc.16.112

• of N/O-containing heterocycles used as the key intermediates in the synthesis of more complex cyclic and acyclic compounds, including various biologically active molecules. Here, we present a fast and highly stereoselective approach towards both C-3/4-cis and C-3/4-trans isomers of 3-substituted

• hydroxylamines using malonoyl peroxide, providing N-tosylated 3-aryl-substituted 4-hydroxyisoxazolidines in a highly stereoselective manner in favor of the C-3/4-trans isomers [27]. We believe that the 3-substituted isoxazolidin-4-ols, represented by the general structures of the trans and the cis stereoisomer 3

• hydrolysis of the corresponding N-Troc intermediate was successfully exemplified on the 3-isopropyl-substituted derivative. We believe that the presented method will provide a fast and highly stereoselective approach towards both C-3/4-cis and C-3/4-trans isomers of 3-substituted isoxazolidin-4-ols as

Ferrocenyl-substituted tetrahydrothiophenes via formal [3 + 2]-cycloaddition reactions of ferrocenyl thioketones with donor–acceptor cyclopropanes

• Grzegorz Mlostoń,
• Mateusz Kowalczyk,
• André U. Augustin,
• Peter G. Jones and
• Daniel B. Werz

Beilstein J. Org. Chem. 2020, 16, 1288–1295, doi:10.3762/bjoc.16.109

• present study also demonstrated the growing potential of donor–acceptor cyclopropanes [24][25][26][27][28] as unique building blocks for current organic synthesis and especially for the efficient and highly stereoselective preparation of the relevant five-membered sulfur heterocycles derived from

Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones

• Valeria Nori,
• Antonio Arcadi,
• Armando Carlone,
• Fabio Marinelli and
• Marco Chiarini

Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95

• -substituted and unsubstituted at the propargylic position) were successfully used as starting materials, affording the corresponding products 4eb, 4fc and 4fj in good yields. According to the literature, the highly stereoselective formation of products 4 resulted from the intramolecular syn-addition of the in

Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

• obtained by Lee who carried out an intermolecular enyne metathesis between an alkynyl boronate and an olefinic substrate in the presence of the Grubbs 2nd generation catalyst [71]. The reaction was highly stereoselective and favored the formation of the desired E-isomer (E/Z = 7.5:1). The functionalization