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

• the C-nucleophile on 81 is very slow, which determines the chemoselectivity of the reaction. Complex 83 of the iminium ion and the catalyst then reacts with allylsilane 84 through an open, type 2 [33] transition state from the exposed enantiotopic face, as in int-79, to afford product 85 and to

Functionalization of imidazole N-oxide: a recent discovery in organic transformations

• Koustav Singha,
• Imran Habib and
• Mossaraf Hossain

Beilstein J. Org. Chem. 2022, 18, 1575–1588, doi:10.3762/bjoc.18.168

• to be a 1:1:1 ratio of 2-unsubstituted imidazole N-oxides as C-nucleophile, ethyl cyanoacetate as C–H acidic electrophile and 4-(methylsulfanyl)benzaldehyde as aldehyde catalyst, DMF as solvent at 100 °C for 5 h. Under the optimized conditions, malononitrile providing the products 4i,j (36–45%), 2

• reflux for 5 h. In this operationally simple procedure, the imidazole N-oxide plays the role of a ‘C’-nucleophile when there is no involvement of acid or base catalyst. 1-Benzyl-4,5-dimethylimidazole N-oxide (28) was chosen as the N-oxide substrate to react with Meldrum’s acid (26) and several aldehydes

Asymmetric Mannich reactions of (S)-N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimines with yne nucleophiles

• Ziyi Li,
• Li Wang,
• Yunqi Huang,
• Haibo Mei,
• Hiroyuki Konno,
• Hiroki Moriwaki,
• Vadim A. Soloshonok and
• Jianlin Han

Beilstein J. Org. Chem. 2020, 16, 2671–2678, doi:10.3762/bjoc.16.217

• afford diastereomerically pure compounds. The purified Mannich addition products were deprotected to give the target enantiomerically pure trifluoromethylpropargylamines. A mechanistic rationale for the observed stereochemical outcome is discussed. Keywords: arylethynes; asymmetric Mannich reaction; C

• -nucleophile; CF3-aldimine; fluorinated propargylamine; Introduction In recent years, substitution of hydrogen by fluorine atoms or fluorine-containing groups usually provides unexpected biological and physicochemical properties, which thus has become an established approach for the development of

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• diastereoselective Michael addition reactions [103][104]. The glycine–nickel complex 184 was deprotonated using a radical anion generated from the electrochemical reduction of azobenzene. The anionic Ni complex 185 acted as a good C-nucleophile towards Michael acceptors 186 resulting in diastereoisomeric mixtures of

Steroid diversification by multicomponent reactions

• Leslie Reguera,
• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Daniel G. Rivera

Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121

• androstanic steroids. Such heterocyclic moieties are of interest because of their pharmacological activity, for example, as anti-inflammatory agents. Employing epiandrosterone and benzaldehyde as oxo components, ammonium acetate and malononitrile as C-nucleophile, the authors produced 2-amino-3-cyano-1,4

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

• Grzegorz Mlostoń and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

• onto the terminal cyano group in 85 results in the formation of the minor product 83. Another example of a heterocyclization, which occurs with participation of an N- and a C-nucleophile was reported for the reaction of E-1a and thiosemicarbazone 86, derived from furfural. This reaction, performed in

Conjugated nitrosoalkenes as Michael acceptors in carbon–carbon bond forming reactions: a review and perspective

• Yaroslav D. Boyko,
• Valentin S. Dorokhov,
• Alexey Yu. Sukhorukov and
• Sema L. Ioffe

Beilstein J. Org. Chem. 2017, 13, 2214–2234, doi:10.3762/bjoc.13.220

• indolactam-based alkaloids 84 (activators of protein kinase C) as shown in Scheme 30. Employing the same strategy, Webb [76] and Resnick [77] prepared analogues of teleocidin and later Quick [78] accomplished the synthesis of indolactam V. Tandem C-nucleophile addition/cyclization processes involving

Regiodivergent condensation of 5-alkoxycarbonyl-1H-pyrrol-2,3-diones with cyclic ketazinones en route to spirocyclic scaffolds

• Alexey Yu. Dubovtsev,
• Maksim V. Dmitriev,
• Аndrey N. Maslivets and
• Michael Rubin

Beilstein J. Org. Chem. 2017, 13, 2179–2185, doi:10.3762/bjoc.13.218

• product of 1,2-addition of the C-nucleophile to the most reactive keto function and subsequent nucleophilic attack by the O-enolate on the conjugate C=C bond activated by two electron acceptors could become more preferable as compared to the alternative “normal” pathway, leading to adducts 10 and

Substitution of fluorine in M[C₆F₅BF₃] with organolithium compounds: distinctions between O- and N-nucleophiles

• Anton Yu. Shabalin,
• Nicolay Yu. Adonin and
• Vadim V. Bardin

Beilstein J. Org. Chem. 2017, 13, 703–713, doi:10.3762/bjoc.13.69

• atom with the fluorine atoms of the BF3 group. This differs from the previously reported substitution in K[C6F5BF3] by O- and N-nucleophiles that did not produce K[2-NuC6F4BF3]. Keywords: C-nucleophile; NMR spectroscopy; nucleophilic substitution; pentafluorophenyltrifluoroborate; Introduction

• gives the related isomers while a complex mixture forms from K[C6F5BF3] and MeLi at the same temperature. K[C6F5BF3] does not react with PhC≡CLi in DME–ether under reflux because the low reactivity of C-nucleophile. 2. Because solutions of MeLi and PhLi contain LiBr or LiI, the salts M[C6F5BF3] (M = K

A modular approach to neutral P,N-ligands: synthesis and coordination chemistry

• Vladislav Vasilenko,
• Torsten Roth,
• Clemens K. Blasius,
• Sebastian N. Intorp,
• Hubert Wadepohl and
• Lutz H. Gade

Beilstein J. Org. Chem. 2016, 12, 846–853, doi:10.3762/bjoc.12.83

• repulsion of the neighboring groups [11]. The methodology for the synthesis of compounds 2 and 3 was also applied to the preparation of phosphine imine ligand 5. Instead of a formamidine precursor, imine 4 was employed as the nucleophile. Deprotonation of 4 at low temperature and addition of the resulting C

• -nucleophile to chlorodiphenylphosphine gave the desired product in good yield (Scheme 2) [13]. This modification renders the phosphorus donor site more electron rich and also results in a more robust P–C bond compared to ligands 2 and 3. For the preparation of ligand 7 the order of bond formations of the

The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles

• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess and
• Viktor I. Saloutin

Beilstein J. Org. Chem. 2015, 11, 385–391, doi:10.3762/bjoc.11.44

• possibility of tetrazolopyrimidine F formation since it has the peak of (m/z 269 [M − H2O]+). Then tetrazolopyrimidine F adds benzoylacetic ester (8) as a C-nucleophile at the electrophilic CH-center. The reaction is accompanied by tetrazole rearrangement through the formation of intermediate G to give

Tricyclic flavonoids with 1,3-dithiolium substructure

• Lucian G. Bahrin,
• Peter G. Jones and
• Henning Hopf

Beilstein J. Org. Chem. 2012, 8, 1999–2003, doi:10.3762/bjoc.8.226

• [30]. This behavior opens the way for the synthesis of various substituted 1,3-dithiolic rings, especially those with a 2-ylidene moiety resulting from a C-nucleophile attack. Furthermore, by using oxygen, sulfur, phosphorus, or nitrogen nucleophiles, interesting and novel structures can in principle