Beyond symmetric self-assembly and effective molarity: unlocking functional enzyme mimics with robust organic cages

• Keith G. Andrews

Beilstein J. Org. Chem. 2025, 21, 421–443, doi:10.3762/bjoc.21.30

• ][383][384][385], and do not require metal parameterization [140][386][387]. Catalysis: Stable, soluble organic cages finally open the possibility of organocatalysis in confined spaces: organization and polarization. Hexapyridyl cage 2 was shown to accelerate acyl transfer esterification reactions by

• that might permit tuning of several consecutive catalytic steps [395], induced-fit binding, product release, allostery [396][397], or signaling. For the acyl transfer reaction, cage 1 is an inferior catalyst compared to cage 2, which we have postulated is due to the larger equilibrium cage height

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

• selectively transfer the acyl or acylthio moieties. Arylboronic acids 74 and amines 76 were suitable for the acyl transfer and led to ketones 78 and amides 80 as the desired products. While, Grignard reagents 75 and thiols 77 acted as soft nucleophiles and resulted in thioesters 79 and acyl disulfides 81

First example of organocatalysis by cathodic N-heterocyclic carbene generation and accumulation using a divided electrochemical flow cell

• Daniele Rocco,
• Ana A. Folgueiras-Amador,
• Richard C. D. Brown and
• Marta Feroci

Beilstein J. Org. Chem. 2022, 18, 979–990, doi:10.3762/bjoc.18.98

• [33]. Flow electrochemistry was applied to oxidize the Breslow intermediate to the corresponding electrophilic acylthiazolium intermediate, which then functioned as an acyl-transfer reagent, reacting with alcohols or amines. To the best of our knowledge, only one research group reported the cathodic

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• catalysts that allow ON/OFF reaction control in photoredox catalysis [120], phosphate diester transesterification [121], Friedel–Crafts reaction, ring opening of epoxides, oligomerization [116], and acyl-transfer reactions [122][123]. While there are further examples by Mirkin [124][125][126], Schmittel

• distance, now though for proximity catalysis using acyl transfer. The utility of this approach was demonstrated when a duo of catalysts was used for achieving substrate selectivity [133]. In detail, nanoswitch [Cu(130)]+ was transformed into the slow rotor [Cu2(130)]2+ (k298 = 1.34 s−1) upon the addition

New advances in asymmetric organocatalysis

• Radovan Šebesta

Beilstein J. Org. Chem. 2022, 18, 240–242, doi:10.3762/bjoc.18.28

• Waser employed an isothiourea catalyst for esterification-mediated kinetic resolution of paracyclophane derivatives with planar chirality [19]. Parida and Pan showed that a Michael reaction coupled with an acyl transfer reaction between α-nitroketones and 4-arylidenepyrrolidine-2,3-diones can produce a

Organocatalytic asymmetric Michael/acyl transfer reaction between α-nitroketones and 4-arylidenepyrrolidine-2,3-diones

• Chandrakanta Parida and
• Subhas Chandra Pan

Beilstein J. Org. Chem. 2021, 17, 1447–1452, doi:10.3762/bjoc.17.100

• Chandrakanta Parida Subhas Chandra Pan Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati, Assam, 781039, India 10.3762/bjoc.17.100 Abstract An organocatalytic asymmetric Michael/acyl transfer reaction between α-nitroketones and 4-arylidenepyrrolidine-2,3-diones is

• reported. A bifunctional thiourea catalyst was found to be effective for this reaction. With 10 mol % of the catalyst, good results were attained for a variety of 1,5-dihydro-2H-pyrrol-2-ones under mild reaction conditions. Keywords: acyl transfer; enantioselectivity; Michael reaction; organocatalysis

• -nitroketones have been found to be a popular nucleophilic acyl transfer reagent. In 2011, three research groups namely Wang, Yan and Kwong independently revealed the organocatalytic asymmetric conjugate addition of α-nitroketones to β,γ-unsaturated α-keto esters with the concomitant acyl transfer reaction to

Chiral isothiourea-catalyzed kinetic resolution of 4-hydroxy[2.2]paracyclophane

• David Weinzierl and
• Mario Waser

Beilstein J. Org. Chem. 2021, 17, 800–804, doi:10.3762/bjoc.17.68

• = 20; C = 57%) and allowing for the isolation of (Rp)-2 in 39% yield (94% ee) and (Sp)-3a in 53% yield (71% ee) (Table 1, entry 11). Mechanistically, this resolution process should proceed via the well-understood formation of a chiral acyl-transfer species between the isothiourea catalyst ITU 2 and the

• rac-2 with anhydride 4aa. Supporting Information Supporting Information File 70: Copies of NMR spectra and HPLC chromatograms as well as analytical data of esters 3 obtained with the alternative acyl-transfer reagents 4. Acknowledgements We are grateful to Thomas Bögl (Institute of Analytical

Application of chiral 2-isoxazoline for the synthesis of syn-1,3-diol analogs

• Juanjuan Feng,
• Tianyu Li,
• Jiaxin Zhang and
• Peng Jiao

Beilstein J. Org. Chem. 2019, 15, 1840–1847, doi:10.3762/bjoc.15.179

• quantitative yield. PTSA-catalyzed removal of THP in 20 in methanol did occur. However, concomitant monodeacylation as well as further an acyl-transfer reaction also took place, resulting in a mixture. These results indicated THP, isopropylidene or Ac protection to primary or secondary hydroxy groups did not

One-pot activation–alkynylation–cyclization synthesis of 1,5-diacyl-5-hydroxypyrazolines in a consecutive three-component fashion

• Christina Görgen,
• Katharina Boden,
• Guido J. Reiss,
• Walter Frank and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 1360–1370, doi:10.3762/bjoc.15.136

• -diacyl-5-hydroxypyrazolines is concise, highly efficient and diversity-oriented. The deacylating aromatization of the title compounds under weakly alkaline or acidic conditions indicates acyl-transfer ability. Furthermore, the peculiar reactivity of the ynedione intermediate calls for more sophisticated

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

• MCR is due to the ring contraction of the 7-membered ring cyclic intermediate by transannular acyl transfer, which leads to the β-lactam derivative. Despite the chiral nature of the steroidal substrate, no significant stereoselective induction was observed, probably because the 7-membered ring

Synthesis of a novel category of pseudo-peptides using an Ugi three-component reaction of levulinic acid as bifunctional substrate, amines, and amino acid-based isocyanides

• Maryam Khalesi,
• Azim Ziyaei Halimehjani and
• Jürgen Martens

Beilstein J. Org. Chem. 2019, 15, 852–857, doi:10.3762/bjoc.15.82

• electrophilic centre of the iminium ion in B is subjected to a nucleophilic attack of the isocyanide to furnish the intermediate C. Then, a second nucleophilic addition takes place at this nitrilium intermediate C with an intramolecular nucleophilic addition of the carboxylate anion. The final step is an acyl

• transfer from oxygen to nitrogen (Mumm rearrangement) in D which completes the Ugi reaction accompanied by formation of the corresponding bis-amides. The structure of products was confirmed by IR, 1H and 13C NMR, CHN and HRMS analyses and by X-ray crystallography for 4a. The IR spectra of the derivatives

The LANCA three-component reaction to highly substituted β-ketoenamides – versatile intermediates for the synthesis of functionalized pyridine, pyrimidine, oxazole and quinoxaline derivatives

• Tilman Lechel,
• Roopender Kumar,
• Mrinal K. Bera,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2019, 15, 655–678, doi:10.3762/bjoc.15.61

• D thus accomplishing the final connectivity of the three components. Enol/carbonyl tautomerization gives the isolated β-ketoenamide KE with E-configuration being the result of the intramolecular acyl transfer. Even after storage of β-ketoenamides there is no evidence that an isomerization to the

Functionalization of graphene: does the organic chemistry matter?

• Artur Kasprzak,
• Agnieszka Zuchowska and
• Magdalena Poplawska

Beilstein J. Org. Chem. 2018, 14, 2018–2026, doi:10.3762/bjoc.14.177

• alcohol. This leads to the formation of the desired ester bond (Figure 3, step e). DMAP acts both as a nucleophile and an acyl transfer reagent and suppresses the side reactions. The structure of GO includes a number of epoxide moieties, which are also reactive toward the nucleophilic reagents. The

Polyketide stereocontrol: a study in chemical biology

• Kira J. Weissman

Beilstein J. Org. Chem. 2017, 13, 348–371, doi:10.3762/bjoc.13.39

Tunable microwave-assisted method for the solvent-free and catalyst-free peracetylation of natural products

• Manuela Oliverio,
• Paola Costanzo,
• Monica Nardi,
• Carla Calandruccio,
• Raffaele Salerno and
• Antonio Procopio

Beilstein J. Org. Chem. 2016, 12, 2222–2233, doi:10.3762/bjoc.12.214

• hydroxy groups are unstable in neutral, slight alkaline or oxidative environments [4]. Furthermore, acetylation is a chemical modification well accepted in a biological environment, being the N-acetylation, N,O-acyl transfer and the deacetylation some of the metabolic processes mediated by cytosolic and

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• state, the substituents are oriented with minimal steric hindrance to give the E,E-configured nine-membered ring. Ring contraction reactions of 13-membered lactams afford cyclononenes via intramolecular acyl transfer reactions. The configuration of the double bond derives from precursor D and thus

• for the key intramolecular acyl transfer reaction to form the cyclononene motif. After sodium periodate oxidation of sulfide 56 to the corresponding sulfoxide, addition of lithium diisopropylamide initiated the intramolecular acyl transfer and led to formation of cyclononene 57 in quantitative yield

• . Reductive desulfonylation and a final Wittig olefination of the ketone then afforded racemic β-caryophyllene (22). In summary, the total synthesis of β-caryophyllene was achieved in 19 steps with an overall yield of 6.3%. Although the key intramolecular acyl transfer reaction for construction of the

One-pot odourless synthesis of thioesters via in situ generation of thiobenzoic acids using benzoic anhydrides and thiourea

• Mohammad Abbasi and
• Reza Khalifeh

Beilstein J. Org. Chem. 2015, 11, 1265–1273, doi:10.3762/bjoc.11.141

• many uses in organic synthesis as intermediates, mild acyl transfer agents and thiol sources [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Thioesters can be synthesized in the laboratory by means of different methods using diverse reagents and substrates [20][21][22][23][24][25

Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

• Tor E. Kristensen

Beilstein J. Org. Chem. 2015, 11, 446–468, doi:10.3762/bjoc.11.51

First chemoenzymatic stereodivergent synthesis of both enantiomers of promethazine and ethopropazine

• Paweł Borowiecki,
• Daniel Paprocki and
• Maciej Dranka

Beilstein J. Org. Chem. 2014, 10, 3038–3055, doi:10.3762/bjoc.10.322

• ). Consideration of the results summarized in Table 2 leads to the conclusion that the highest enantioselectivity (E = 844) of the reaction has been observed in the acylation of racemic alcohol (±)-3 in the presence of Lipozyme TL IM, and vinyl acetate as an acyl transfer reagent. In accordance with the previous

• . As a conclusion, the enantioselectivity and rate of lipase-catalyzed KR of (±)-3 in MTBE were significantly affected by the nature of an acyl transfer reagent, thus allowing the excellent enantiomer separation with 3 equiv of vinyl butanoate (Table 2, entries 11 and 12). However, enzymatic kinetic

Efficient Cu-catalyzed base-free C–S coupling under conventional and microwave heating. A simple access to S-heterocycles and sulfides

• Silvia M. Soria-Castro and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2013, 9, 467–475, doi:10.3762/bjoc.9.50

• finally affords heterocycle 6. The free thiol 7 can be also generated by acyl transfer from 2-mercaptoanhydride 11 (Scheme 5). By optimizing the reaction conditions, it was possible to improve the yield of 6. Hence, the copper-catalyzed reaction between iodide 9 and 1 in a ratio of 1:2 rendered only

Cation affinity numbers of Lewis bases

• Christoph Lindner,
• Raman Tandon,
• Boris Maryasin,
• Evgeny Larionov and
• Hendrik Zipse

Beilstein J. Org. Chem. 2012, 8, 1406–1442, doi:10.3762/bjoc.8.163

• substrate model for acyl-transfer reactions. Affinities towards these cationic electrophiles are complemented by data for Lewis-base addition to Michael acceptors as prototypical neutral electrophiles. Keywords: ab initio; cation affinity; Lewis basicity; organocatalysis; proton affinity; Introduction

• example, the case in all acyl transfer reactions catalyzed by pyridine bases which involve acetylpyridinium cations as intermediates of the catalytic cycle [7][41][42][43][44][45][46]. The acetyl cation may be considered to be a representative cationic probe for this type of situation and the

• large increase in the ACA value. This is due to the formation of close contacts between the amide substituent and the acetylpyridinium moiety in the acetylated catalysts (Figure 11). 3,4-Diaminopyridines have been shown to be particularly effective as acyl transfer catalysts. This is also visible in the

Building photoswitchable 3,4'-AMPB peptides: Probing chemical ligation methods with reducible azobenzene thioesters

• Gehad Zeyat and
• Karola Rück-Braun

Beilstein J. Org. Chem. 2012, 8, 890–896, doi:10.3762/bjoc.8.101

• 4,5,6-trimethoxy-2-mercaptobenzyl auxiliary as well as the Nα-2-mercaptoethyl auxiliary. Thus, 3,4'-AMPB derivatives/peptides proved to be significantly less prone to reduction by aliphatic and aromatic thiols than were the 4,4'-AMPB compounds. Keywords: acyl transfer auxiliary; azobenzenes; ligation

• enhance the stability of the diazene unit [4][5]. Since methods based on native chemical ligation (NCL), e.g., NCL with Nα-acyl transfer auxiliaries, have gained considerable interest in the past two decades [6], we reasoned that a comparative ligation study with the Boc-protected azobenzene ω-amino acids

• chemoselective bimolecular thioester exchange prior to the S- to N-acyl transfer through a five-membered transition state for Cys-peptide 3, a six-membered transition state for 4,5,6-trimethoxy-2-mercaptobenzyl auxiliary peptide 5, and a sterically more demanding five-membered transition state for racemic Nα-2

Natural product biosyntheses in cyanobacteria: A treasure trove of unique enzymes

• Jan-Christoph Kehr,
• Douglas Gatte Picchi and
• Elke Dittmann

Beilstein J. Org. Chem. 2011, 7, 1622–1635, doi:10.3762/bjoc.7.191

• product. The initiation module of curacin biosynthesis contains a GCN5-related N-acetyltransferase (GNAT) domain. These enzymes typically catalyze acyl transfer to a primary amine. The curacin GNAT, however, was shown to be bifunctional and to exhibit decarboxylase/S-acetyltransferase activities [45]. The

Achiral bis-imine in combination with CoCl₂: A remarkable effect on enantioselectivity of lipase-mediated acetylation of racemic secondary alcohol

• K. Arunkumar,
• M. Appi Reddy,
• T. Sravan Kumar,
• B. Vijaya Kumar,
• K. B. Chandrasekhar,
• P. Rajender Kumar and
• Manojit Pal

Beilstein J. Org. Chem. 2010, 6, 1174–1179, doi:10.3762/bjoc.6.134

• -2, affording the desired product 5. The CoCl2 in combination with 3i perhaps forms a tight complex with T-1 as well as 4 which facilitates the acyl transfer process (Scheme 4). However, the reason for selective acylation was not clearly understood. It was speculated that the orientation of the

• hydroxy group of the (R)-isomer was possibly in the proximal position of the acyl-transfer site and the imidazole moiety for proton abstraction. Finally, application of this methodology was demonstrated in preparing the well-known drug rivastigmine which has been used to treat mild to moderate dementia