A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• organocatalysts has been a major breakthrough in the realization of enantioselective transformations. Stereoselective synthesis is essential in the pharmaceutical industry, as the development of drugs often requires the production of enantiomerically pure chiral compounds [6][7][8]. The application of

• cinchona squaramide organocatalyst. Its catalytic activity and recyclability were examined in a new stereoselective synthesis of baclofen, which is used to treat muscle spasms [30]. Finally, the catalyst was easily recycled by centrifugation over five reaction cycles without significant loss of activity

• literature [41]. Application of cinchona squaramide 1 and recyclable, lipophilic cinchona squaramide organocatalysts 2 in a new, gram-scale stereoselective synthesis of baclofen precursor. Classification of the tested non-polar solvents according to the GSK’s solvent sustainability guide [34]. Recycling of

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• NaH, DMF) were applied to prepare enantiopure (R)-6.1 or (S)-6.1 from commercially available enantiopure solketal [75][76][78]. For the protected secondary alcohol of the glycerol derivative 6.6a (Figure 6B), a stereoselective synthesis, starting from either ᴅ- or ʟ-tartaric acids, produced first the

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

• . Except lately, in 2020, Chen and group [82] reported a Pd/Cu-catalyzed regio- and stereoselective synthesis of C2-alkenylated pyridines starting from internal alkynes 84 and pyridinium salts in a stereodivergent manner (Scheme 17a). The interesting part of this work was the switching of the alkene

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

• contains six contiguous stereogenic centers out of which four are all-carbon quaternary stereocenters. The authors have achieved the stereoselective synthesis of waihoensene for the first time with a 3.8% overall yield (15 steps) (Scheme 59). The construction of the triquinane core included a Cu-catalyzed

• in the first step by the phosphoramidite ligand L39 (92% ee, dr 1:1) (Scheme 60). Recently, Liu and co-workers reported the stereoselective synthesis of the tricyclic core of dodecahydrodibenzo[b,d]furan skeleton containing 12-epi-JBIR-23 and -24 [111]. Besides their intriguing complex structures

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• base chiral template is a fairly versatile “tool” that can be adapted to a specific task. A relatively new approach to functionalization of amino acids is a combination of a stereoselective synthesis in a metal-coordination environment with electrochemical activation [31]. It increases the reactivity

• new ligand and amino acids (glycine and dehydroalanine) will find their rightful place in the stereoselective synthesis of tailor-made amino acids (including oxidative transformations). Fragment of the NOESY spectrum of the ʟ-(oBrCysNi)L7 complex indicating the correlation between the H-2 and H-17,21

Asymmetric synthesis of a stereopentade fragment toward latrunculins

• Benjamin Joyeux,
• Antoine Gamet,
• Nicolas Casaretto and
• Bastien Nay

Beilstein J. Org. Chem. 2023, 19, 428–433, doi:10.3762/bjoc.19.32

• precluded the installation of the pyran ring – and the use of its well-known isomerization to set up important stereocenters [6][9] –, thus imposing the anticipated construction of key asymmetric centers. The following discussion will deal with the stereoselective synthesis of a stereopentade amenable to

Total synthesis of insect sex pheromones: recent improvements based on iron-mediated cross-coupling chemistry

• Eric Gayon,
• Guillaume Lefèvre,
• Olivier Guerret,
• Adrien Tintar and
• Pablo Chourreu

Beilstein J. Org. Chem. 2023, 19, 158–166, doi:10.3762/bjoc.19.15

• issues for living organisms [25][26]. Additionally, the classic stereoselective synthesis of dienol phosphates requires cryogenic temperatures (−78 °C) as well as NMP-based methodologies [27]. Therefore, motivated by those considerations, we sought a suitable efficient and non-toxic additive which would

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

• formation of the cis-vinylcyclopropanes (Scheme 18c and 18d). Desulfurization of the adducts again yields the product of a formal cyclopropanation with a ‘naked’ vinyl carbene species, as demonstrated by the stereoselective synthesis of the protected cis-2-vinylcyclopropan-1-amine 123 (Scheme 18d). 7

• ][57]. Stereoselective 5,6-dihydro-1,4-dithiin-based synthesis of cis-olefins [42][58]. Addition to aldehydes and applications in stereoselective synthesis. Direct C–H functionalization methods for 1,4-dithianes [82][83]. Known cycloaddition reactivity modes of allyl cations [84][85][86][87][88][89][90

Synthetic study toward the diterpenoid aberrarone

• Liang Shi,
• Zhiyu Gao,
• Yiqing Li,
• Yuanhao Dai,
• Yu Liu,
• Lili Shi and
• Hong-Dong Hao

Beilstein J. Org. Chem. 2022, 18, 1625–1628, doi:10.3762/bjoc.18.173

• . Impressed by the structural features and biological profiles, our group embarked a project on the total synthesis of this natural product. Herein, we report our stereoselective synthesis of its 6-5-5 tricyclic skeleton. Our retrosynthetic analysis is shown in Scheme 1. For the formation of the D ring with

First total synthesis of hoshinoamide A

• Haipin Zhou,
• Zihan Rui,
• Yiming Yang,
• Shengtao Xu,
• Yutian Shao and
• Long Liu

Beilstein J. Org. Chem. 2021, 17, 2924–2931, doi:10.3762/bjoc.17.201

• synthesized in high efficiency. After systematic screening of the coupling reagents in liquid phase, the key intermediate tripeptide 7 was obtained in high yield. The solid-phase synthesis improves the entire efficiency of the synthetic route. This strategy could be applied to the stereoselective synthesis of

Ligand-dependent stereoselective Suzuki–Miyaura cross-coupling reactions of β-enamido triflates

• Tomáš Chvojka,
• Athanasios Markos,
• Svatava Voltrová,
• Radek Pohl and
• Petr Beier

Beilstein J. Org. Chem. 2021, 17, 2657–2662, doi:10.3762/bjoc.17.179

• isomerization of N-allyl amides [20], but still possess drawbacks, especially for stereoselective synthesis of tri- and tetrasubstituted enamides. Recently, we have reported a triflic acid-mediated reaction of N-fluoroalkyl-1,2,3-triazoles leading to (Z)-β-enamido triflates [21] and Lewis acid-mediated reaction

• configuration of the double bond were formed preferably. Both conditions were applied to a range of arylboronic acids and (Z)-β-enamido triflates. A: Synthesis of (Z)-β-enamido triflates and subsequent stereoselective cross-coupling reactions. B: Ligand-controlled stereoselective synthesis of β,β-diaryl

Solvent-free synthesis of enantioenriched β-silyl nitroalkanes under organocatalytic conditions

• Akhil K. Dubey and
• Raghunath Chowdhury

Beilstein J. Org. Chem. 2021, 17, 2642–2649, doi:10.3762/bjoc.17.177

• Enantioenriched organosilanes are attractive molecules in organic synthesis owing to their potential applications in stereoselective synthesis [1][2]. The unique sterical and electronical features of the C–Si bond can induce stereodifferentiation at the adjacent prostereogenic center in organic transformations [2

N-Sulfinylpyrrolidine-containing ureas and thioureas as bifunctional organocatalysts

• Viera Poláčková,
• Dominika Krištofíková,
• Boglárka Némethová,
• Renata Górová,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2021, 17, 2629–2641, doi:10.3762/bjoc.17.176

• -Butanesulfinamide is highly useful in stereoselective synthesis as a stereoinducing group [21]. Thus, N-sulfinylureas and thioureas are a new class of organocatalysts, with the sulfinyl group acting both as an acidifying and a chiral controlling moiety. A variety of N-sulfinylureas catalyzed aza-Henry reaction

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• -MRs, each highlighting a certain aspect of the reaction. While Sánchez-Roselló et al. [18] classified these reactions on the basis of the nature of the substrates, Nayak et al. [19] and Bhanja et al. [20] focused on the stereoselective synthesis of nitrogen heterocycles via Michael cascade reactions

Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• . Synthesis of tricyclic heterocyclic scaffolds. HgCl2-mediated cyclization of 2-alkynylphenyl alkyl sulfoxide. a) Hg(OTf)2-catalyzed cyclization of allenes and alkynes. b) Proposed mechanism of cyclization. Stereoselective synthesis of tetrahydropyran derivatives. a) Hg(ClO4)2-catalyzed cyclization of α

Transition-metal-free intramolecular Friedel–Crafts reaction by alkene activation: A method for the synthesis of some novel xanthene derivatives

• Tülay Yıldız,
• İrem Baştaş and
• Hatice Başpınar Küçük

Beilstein J. Org. Chem. 2021, 17, 2203–2208, doi:10.3762/bjoc.17.142

• method using π-activated alcohols has frequently been used for xanthene synthesis. Some of these methods are the stereoselective synthesis of 9-vinyl-substituted unsymmetrical xanthenes and thioxanthenes by intramolecular FCA reaction [39], Lewis acid-catalyzed intramolecular FCA [40], and the synthesis

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

• considerably reduced the time needed for the stereoselective synthesis of linear α(1–6)-mannans (ranging from 5mer to 20mer) [275]. The biggest advantage of this approach is the easy scalability, up to a gram scale. However, this strategy is limited to one type of linkage (i.e., only α(1–6) linkages) and does

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

• determined following a single-crystal X-ray analysis (Scheme 11). The stereoselective synthesis of diastereomeric 2-chloro-2-aroylaziridines 36 and 32 was successfully accomplished through a three-component cascade coupling reaction of silyldichloromethanes 33, arylnitriles 34 and chiral N-tert

• through a cyclic transition state to the Si face of the imine (RS)-14. In this way, both cis-aziridines diastereoisomers 36 and 32 were formed from the same chiral imine 14 and arylnitriles 34 (Scheme 12). Chiral sulfinyl imines have been also used in the stereoselective synthesis of aziridines. The

• pharmacy as highly biological active compounds. Among this group of nitrogenated heterocycles, β-lactams (azetidin-2-ones) have reached especial attention [78][79][80], being easily accessible from β-aminoesters. A stereoselective synthesis of 1-substituted 2-azaspiro[3.3]heptanes 45 (n = 1) was reported

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

• aminohydroxylation process starting from allylic carbamates usually carried out in the presence of potassium osmate [24][25][26][27][28]. In recent years, we have extensively studied the stereoselective synthesis, as well as catalytic and pharmacological applications of monoterpene-based 3-amino-1,2-diols, which are

• oxazolidin-2-one 9. NOESY experiments and X-ray structure proofment of the structure of oxazolidine 17. Proposed pathway for the ring–ring tautomerism. Stereoselective synthesis of the pinane-fused oxazolidin-2-one 9. Stereoselective synthesis of the pinane spiro-fused oxazolidin-2-one 12. Parallel synthesis

Metal-free glycosylation with glycosyl fluorides in liquid SO₂

• Krista Gulbe,
• Jevgeņija Lugiņina,
• Edijs Jansons,
• Artis Kinens and
• Māris Turks

Beilstein J. Org. Chem. 2021, 17, 964–976, doi:10.3762/bjoc.17.78

• facilitating for the synthesis of 2-deoxy glucoside 20 from corresponding fluoride α-19 in 91% yield and good α-selectivity at −10 °C (Scheme 5). Due to the absence of a neighboring group at C2 position, the stereoselective synthesis of 2-deoxy glycosides is challenging [72][73][74]. We hypothesize that the

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

• important building blocks and ubiquitous scaffolds in many natural products and active pharmaceutical ingredients (API). Among various established methods, the Prins reaction has emerged as a powerful technique in the stereoselective synthesis of the tetrahydropyran skeleton with various substituents, and

• metathesis (RCM) [16], halo etherification [17], reductive etherification [18][19], and metal-mediated cyclization [20][21], etc. are the most frequent strategies utilized for THP ring construction (Scheme 1). Amongst all, the Prins reaction has proven as a powerful technique in the stereoselective synthesis

• underwent Prins-type cyclization in the presence of BF3·OEt2 as well as SnBr4 to deliver the desired 37 and 40, respectively, without loss of optical purity (Scheme 9) [34][35]. This strategy was successfully utilized for the synthesis of the natural product (−)-centrolobine [33] and for the stereoselective

Highly regio- and stereoselective phosphinylphosphination of terminal alkynes with tetraphenyldiphosphine monoxide under radical conditions

• Dat Phuc Tran,
• Yuki Sato,
• Yuki Yamamoto,
• Shin-ichi Kawaguchi,
• Shintaro Kodama,
• Akihiro Nomoto and
• Akiya Ogawa

Beilstein J. Org. Chem. 2021, 17, 866–872, doi:10.3762/bjoc.17.72

• Ph2P(O)• as an important species to regioselectively afford 1-phosphinyl-2-phosphinoalkenes. This method can be applied to a wide range of terminal alkynes. We believe that the excellent stereoselectivity to give (E)-isomers is effective for the stereoselective synthesis of (E)-bis(diphenylphosphino

The synthesis of chiral β-naphthyl-β-sulfanyl ketones via enantioselective sulfa-Michael reaction in the presence of a bifunctional cinchona/sulfonamide organocatalyst

• Deniz Tözendemir and
• Cihangir Tanyeli

Beilstein J. Org. Chem. 2021, 17, 494–503, doi:10.3762/bjoc.17.43

• naturally occurring cinchona alkaloids have shown remarkable performance as organocatalysts for stereoselective synthesis in the past decade [1][2][3][4][5][6]. Among them, quinine-derived organocatalysts make a noteworthy appearance in the formation of new stereogenic centres, which can serve as valuable

Diels–Alder reaction of β-fluoro-β-nitrostyrenes with cyclic dienes

• Savva A. Ponomarev,
• Roman V. Larkovich,
• Alexander S. Aldoshin,
• Andrey A. Tabolin,
• Sema L. Ioffe,
• Jonathan Groß,
• Till Opatz and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2021, 17, 283–292, doi:10.3762/bjoc.17.27

• one of the most widely used fluorine-containing building blocks [48][49]. Recently, we have developed an efficient stereoselective synthesis of β-fluoro-β-nitrostyrenes 1 based on the radical nitration of 2-bromo-2-fluorostyrenes [50]. This process takes place with simultaneous elimination of bromine

Progress in the total synthesis of inthomycins

• Bidyut Kumar Senapati

Beilstein J. Org. Chem. 2021, 17, 58–82, doi:10.3762/bjoc.17.7

• contradictions regarding the specific rotation values of inthomycin C and securely assigned the (3R)‑configuration for inthomycin C ((−)-3) [57]. In the synthetic studies towards racemic inthomycin C ((rac)-3), Maulide and co-workers investigated the stereoselective synthesis of halocyclobutenes and their ring