Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• categorized into two major divisions: 1) covalent bonding and 2) noncovalent bonding catalysts. A covalent bonding organocatalyst reacts with a substrate to form an activated chiral intermediate which undergoes a stereoselective reaction with another reagent. A noncovalent bonding catalyst usually assembles

• the reaction partners in a highly ordered three dimensional transition state through noncovalent interactions (like H-bonding, π–π interactions) thus promoting the stereoselective reaction. Examples of covalent bonding organocatalysts are amines [6][7], N-heterocyclic carbenes [8][9], phosphines [10

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

Preparation of an advanced intermediate for the synthesis of leustroducsins and phoslactomycins by heterocycloaddition

• Anaïs Rousseau,
• Guillaume Vincent and
• Cyrille Kouklovsky

Beilstein J. Org. Chem. 2022, 18, 1385–1395, doi:10.3762/bjoc.18.143

• , we have shown that the Wightman reagent 6, a chiral chloronitroso derivative [27], led to a complete regio- and stereoselective reaction with functionalized dienes (Scheme 1). The chiral auxiliary contributes to both regioselectivity and stereoselectivity. After hydrolysis of the chiral auxiliary and

Synthesis of 1,2-divinylcyclopropanes by metal-catalyzed cyclopropanation of 1,3-dienes with cyclopropenes as vinyl carbene precursors

• Jesús González,
• Alba de la Fuente,
• María J. González,
• Laura Díez de Tejada,
• Luis A. López and
• Rubén Vicente

Beilstein J. Org. Chem. 2019, 15, 285–290, doi:10.3762/bjoc.15.25

• stereoselective reaction. Once more, simple ZnCl2 was particularly effective for this reaction in sharp contrast to the incompetence of [Rh2(OAc)4]. It should be noticed that 1,2-divinylcyclopropanes 3a–l did not undergo [3,3]-Cope rearrangements under the reaction conditions. Moreover, when pure endo-3e was

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

• exploited the Michael addition of enolates to nitrosoalkenes in their studies towards syntheses of 3-methoxy-9β-estra(1,3,5(10))trien(11,17)dione (25) (1977) [31] and (+/−)-isocomene (1981) [32]. The key carbon–carbon bond formation step in the synthesis of steroid 25 was the stereoselective reaction of α

(Thio)urea-mediated synthesis of functionalized six-membered rings with multiple chiral centers

• Giorgos Koutoulogenis,
• Nikolaos Kaplaneris and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2016, 12, 462–495, doi:10.3762/bjoc.12.48

• aminoaldehyde product. Finally, the N-protected aminoaldehyde product can now be cyclized under the reactions’ conditions. Another stereoselective reaction was attempted by Kotsuki’s group presenting an organocatalytic hetero-Diels–Alder reaction between isatin 229 with substituted diene 230. High pressure had

Recent advances in N-heterocyclic carbene (NHC)-catalysed benzoin reactions

• Rajeev S. Menon,
• Akkattu T. Biju and
• Vijay Nair

Beilstein J. Org. Chem. 2016, 12, 444–461, doi:10.3762/bjoc.12.47

• the combination of NHC 24 and a Brønsted base (4-methoxyphenolate) promoted a formal dimerisation of 2-(aroylvinyl)arylaldehydes 70 to afford benzo[a]tetrahydrofluorenones 71 [60]. This stereoselective reaction proceeds via a benzoin–Michael–Michael cascade process (Scheme 43). Further investigations

Lewis acid-promoted hydrofluorination of alkynyl sulfides to generate α-fluorovinyl thioethers

• Davide Bello and
• David O'Hagan

Beilstein J. Org. Chem. 2015, 11, 1902–1909, doi:10.3762/bjoc.11.205

• inseparable 9:1 mixture of Z-2b and E-3b isomers in 48% yield. When TiF4 was used, the reaction showed complete stereoselectivity, affording the Z-isomer of 2b in 55% yield. Replacement of the cyclohexyl moiety with a phenyl ring in 1c led to a fully stereoselective reaction both with BF3·Et2O and TiF4

• , giving the Z-stereoisomer 2c in 45% and 57% yields, respectively. We then maintained the phenyl moiety on the alkyne side of the sulfide, and replaced the benzyl group with a cyclohexyl fragment directly connected to the sulfur atom (compound 1d). This material allowed too for a stereoselective reaction

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

• Gijs Koopmanschap,
• Eelco Ruijter and
• Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

• ]. In 2009, the group of Dömling reported an Ugi-approach towards the synthesis of Bacillamide C (Scheme 42) [109]. (R)-Bacillamide C is a natural product with algicidal and antibacterial properties [97]. It was shown that a stereoselective reaction between Schöllkopf’s isocyanide, acetaldehyde

• cyclization provided both (3R,6R,7R)- and (3R,6R,7S)-isomers, in favour of the latter (dr 1:3). However, the minor RRR-isomers 189 showed to have the highest potency and were obtained in yields up to 21%. In a variation, improved stereoselective reaction for the RRR-isomer 189 was observed. After an Ugi 4C-3

Efficient regio- and stereoselective access to novel fluorinated β-aminocyclohexanecarboxylates

• Loránd Kiss,
• Melinda Nonn,
• Reijo Sillanpää,
• Santos Fustero and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2013, 9, 1164–1169, doi:10.3762/bjoc.9.130

• –fluorine or oxo–fluorine exchange. Keywords: amino acids; epoxidation; fluorination; hydroxylation; stereoselective reaction; Introduction Fluorine chemistry is an expanding area of research that has generated increasing interest in pharmaceutical and medicinal chemistry in recent years because of its

Recent advances in transition-metal-catalyzed intermolecular carbomagnesiation and carbozincation

• Kei Murakami and
• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 278–302, doi:10.3762/bjoc.9.34

• . Zirconium-catalyzed alkylmagnesiation. Titanium-catalyzed carbomagnesiation. Three-component coupling reaction. Iron-catalyzed arylzincation reaction of oxabicyclic alkenes. Reaction of allenyl ketones with organomagnesium reagent. Regio- and stereoselective reaction of a 2,3-allenoate. Three-component

Determination of the relative configuration of tropinone and granatanone aldols by using TBDMS ethers

• Ryszard Lazny,
• Aneta Nodzewska,
• Katarzyna Sidorowicz and
• Przemyslaw Kalicki

Beilstein J. Org. Chem. 2012, 8, 1877–1883, doi:10.3762/bjoc.8.216

• isomerization; granatanone; stereoselective reaction; tropinone; Introduction Enantiomerically pure, and racemic, diastereomerically pure aldols of tropinone have been used as key intermediates in stereoselective syntheses of natural tropane alkaloids and their analogues [1], including the unnatural enantiomer

Facile synthesis of functionalized tetrahydroquinolines via domino Povarov reactions of arylamines, methyl propiolate and aromatic aldehydes

• Jing Sun,
• Hong Gao,
• Qun Wu and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2012, 8, 1839–1843, doi:10.3762/bjoc.8.211

• structure we could conclude that the prepared tetrahydroquinolines 1a–1m exist in (2,3)-trans-(3,4)-trans-configuration, which also means that this domino Povarov reaction is a highly stereoselective reaction. A reaction mechanism for this domino Povarov reaction is briefly outlined in Scheme 2 based on the

Solvent-free phase-vanishing reactions with PTFE (Teflon^®) as a phase screen

• Kevin Pels and
• Veljko Dragojlovic

Beilstein J. Org. Chem. 2009, 5, No. 75, doi:10.3762/bjoc.5.75

• stereoselective reaction, that usually is not the case with cis-stilbene and the reaction product is a mixture of D,L- and meso-dibromostilbenes [23][24][25]. Besides the common mechanism involving a bromonium ion as an intermediate, bromination of cis-stilbene may involve the corresponding carbocation [24][25