Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters

• Lewis McGhie,
• Hannah M. Kortman,
• Jenna Rumpf,
• Peter H. Seeberger and
• John J. Molloy

Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69

• reactivity in EnT catalysis has also been intensively pursued (Figure 1B). The controlled geometric isomerization of boron-containing conjugated dienes [42], styrenes [43][44][45] and β-boryl acrylates [46][47] has been established with great effect, while elegant [2 + 2] cycloaddition strategies to readily

• differences in stereoelectronic stabilization of the transient 1,4-biradical intermediate on changing substituent (CO2R→BPin) [63][64][65]. It is pertinent to note that increased catalyst loading and reaction times were necessary for efficient reactivity with alkenylboronic esters, suggesting acrylates are

• as an operational mechanism. While intermolecular alkene quenching to enable [2 + 2] cycloaddition was inefficient, presumably due to poor substrate lifetime, intramolecular [2 + 2] reactivity with both acrylates and alkenylboronic esters was effective. The small 3D, boron-containing fragments could

Molecular diversity of the reactions of MBH carbonates of isatins and various nucleophiles

• Zi-Ying Xiao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2025, 21, 286–295, doi:10.3762/bjoc.21.21

• reactions of isatins with alkyl acrylates, acrylonitrile, and other activated alkenes [26][27][28][29]. Due to the stronger electron-withdrawing effect of the oxindole motif, MBH carbonates of isatins showed higher reactivity than that of the normal MBH carbonates of normal ketones [30][31][32][33][34][35

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• products in moderate to good yield. Additionally, unsymmetrical DAIRs showed a preference for transferring an electron-poor and sterically less hindered aryl ring. The scope of MBH acetates was further explored, demonstrating compatibility with a wide range of substituted aromatic ethyl acrylates and

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

• Yutaro Miyashita,
• Sae Someya,
• Tomoko Kawasaki-Takasuka,
• Tomohiro Agou and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

• a variety of Rf groups at the 3 position starting from the corresponding 3-Rf-acrylates 1 by the action of the low cost and easy-to-handle reagent, NaOCl·5H2O. The special feature of this process is the requirement of a very mild temperature of 0 °C which can be well compared to the previous one

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

• Stefan P. Schmid,
• Leon Schlosser,
• Frank Glorius and
• Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

• acrylates [95] and found a similar performance compared to NCI probe descriptors. Despite the success of this approach, it is important to remember that descriptors do not have to be parameters of one molecule and that intermolecular terms can be used to derive mechanistic hypotheses. Toste and co-workers

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

• Mithu Roy,
• Bitan Sardar,
• Itu Mallick and
• Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

• components, such as various acrylates, α,β-unsaturated acids, enones, enals, acrylamides, vinyl phosphonates, and vinyl sulfones. Various cesium salts of oxalates also performed well using this protocol. Isopropyl and tert-butyl groups present in an adjacent position of oxalates do not disturb the reaction

(Bio)isosteres of ortho- and meta-substituted benzenes

• H. Erik Diepers and
• Johannes C. L. Walker

Beilstein J. Org. Chem. 2024, 20, 859–890, doi:10.3762/bjoc.20.78

• alkenes including acrylates, vinyl sulfones, and acrylamides could all be incorporated and the number of accessible bifunctional 1,2-BCHs was increased further by chemical transformation (Scheme 3D) [35]. Among the reported transformations were reduction of the ketone (to (±)-34), hydrolysis of the

SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes

• Julien Borrel and
• Jerome Waser

Beilstein J. Org. Chem. 2024, 20, 701–713, doi:10.3762/bjoc.20.64

• reactivity of the C-centered radical with Ph-EBX (2). Aliphatic alkenes, enamides, enol ethers and acrylates were tested in the reaction but did not lead to formation of the desired products (Scheme S1, Supporting Information File 1). In almost all cases >70% of the EBX reagent was left after 16 hours of

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• University of Technology, Stremayrgasse 9, 8010 Graz, Austria 10.3762/bjoc.20.6 Abstract The reactions of 2,4-di-tert-butyl-6-(diphenylphosphino)phenol and various Michael acceptors (acrylonitrile, acrylamide, methyl vinyl ketone, several acrylates, methyl vinyl sulfone) yield the respective phosphonium

• carbanion [13][14]. Also with other Michael acceptors such as methyl vinyl ketone, several acrylates as well as methyl vinyl sulfone the reaction proceeds smoothly under the same reaction conditions (Scheme 1). Conversions of 1 are usually quantitative within 24 h and all phosphonium phenolates can be

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• advantages are (i) the universality to a wide range of monomers such as (meth)acrylates, (meth)acrylamides, dienes, vinyl ethers/esters, etc.; (ii) tolerance to unprotected functionalities in monomers and the solvent including –OH, –COOH, –SO3H, etc.; (iii) different reaction conditions, including bulk

• acrylates, under milder conditions [37][38][39]. Grimaldi et al. [40] achieved NMP of styrene and n-butyl acrylate using SG1-type nitroxide radical (N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl)nitroxide). Compared with TEMPO, SG1 was considered that it initiated the truly “living”/controlled

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• that α-(aminomethyl)acrylates are suitable acceptors for 1,4-additions of dialkylzincs in aerobic conditions. The air-promoted radical–polar crossover process involves the 1,4-addition of an alkyl radical followed by homolytic substitution at the zinc atom of dialkylzinc. Coordination of the nitrogen

• , thereby precluding its synthetic exploitation. Results and Discussion Preparation of α-(aminomethyl)acrylates We commenced our study by preparing a selection of α-(aminomethyl)acrylates with variations of the nitrogen protecting group and the ester substituent. Towards this end, the direct allylation of

• allylation of lithium (trimethylsilyl)amides prepared in situ from the parent amines by a lithiation/silylation/lithiation sequence (Table 1). Using this protocol, α-(aminomethyl)acrylates 5 and 6 derived from benzhydrylamine and aniline were prepared in high yields (Table 1, entries 1 and 2). The procedure

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• , have also been employed in conjugate addition reactions. These reagents are less reactive than organolithium and Grignard reagents but can still add to a range of α,β-unsaturated carbonyl compounds, including enones, acrylates, and imines. In 2011 Sakaguchi and co-worker [64] accomplished the conjugate

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• [12][13][14][15]. On the other hand, Morita–Baylis–Hillman (MBH) carbonates of isatins, which could be easily prepared by the MBH reactions of isatins with acrylonitrile or alkyl acrylates also became valuable synthons [16][17][18][19][20][21][22][23][24][25]. The active 3-methyleneoxindoles could act

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

• challenge. In this context, a regioselective alkylation of ortho-unsubstituted or substituted unactivated pyridines with acrylates and acrylamides under Rh(I) catalysis has been demonstrated by Ellman and co-workers [59]. The authors observed that in the presence of [Rh(cod)Cl]2 as catalyst, dppe as ligand

• , and potassium pivalate (KOPiv) as base, linear C–H-alkylated products 40 were obtained from both acrylates and acrylamides in moderate to high yields (Scheme 9, reaction conditions a). However, when K3PO4 was employed as the base under otherwise identical conditions, the authors observed a switch in

• , acrylates, allenes, and alkynes as coupling partners achieving the functionalized C(sp2)–H-olefinated pyridine frameworks via metal catalysis. ortho-C–H Alkenylation In 2012, Huang and co-workers [74] disclosed a ligand-free oxidative cross-coupling reaction of pyridine with acrylates, acrylamides, and

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• . Among these, Heck reaction conditions allowed for the coupling of aryl acrylates 50 to aryl halides 48 and 49, followed by intramolecular Pd-catalysed amination or etherification to give C-10 carboxylates of dibenzo[b,f]azepine 55 and dibenz[b,f]oxepine 54 in good yield (Scheme 11). However, no ring

• -substituted derivatives were reported. The authors used alpha-substituted acrylates to reduce the effect of poor endo/exo regioselectivity in the intramolecular Heck reaction (cf. Scheme 19). Božinović et al. [52] reported the synthesis of symmetrical 5H-dipyridoazepines 60a and unsymmetrical 5H

Morita–Baylis–Hillman reaction of 3-formyl-9H-pyrido[3,4-b]indoles and fluorescence studies of the products

• Nisha Devi and
• Virender Singh

Beilstein J. Org. Chem. 2022, 18, 926–934, doi:10.3762/bjoc.18.92

• functionalization of the β-carboline framework. Accordingly, 3-formyl-9H-β-carbolines 6a–e were subjected to MBH reaction with acrylonitrile A and various acrylates B–E under neat conditions in the presence of DABCO as depicted in Scheme 2. All the products were furnished smoothly in 27–72% yield. During this study

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

• ethyl and butyl acrylates, but-3-en-2-one, N,N-dimethylacrylamide, acrylonitrile, and phenyl vinyl sulfone. In addition, ethyl 1-arylvinyl-N-phenylphosphonamidates 246 were able to react with methyl acrylate (241), affording methyl 2-(3-aryl-2-ethoxy-2-oxo-1-phenyl-1,5-dihydro-1,2-azaphosphol-5-yl

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• . The C–H olefination of various biaryl-2-amines with acrylates and styrenes was carried out and afforded the desired products 15 in good yields (up to 96% yield) with high enantioselectivities (up to 96% ee). The electronic properties of the side chains of the biaryl compounds have a significant effect

Enantioenriched α-substituted glutamates/pyroglutamates via enantioselective cyclopropenimine-catalyzed Michael addition of amino ester imines

• Zara M. Seibel,
• Jeffrey S. Bandar and
• Tristan H. Lambert

Beilstein J. Org. Chem. 2021, 17, 2077–2084, doi:10.3762/bjoc.17.134

• achieved [31], Michael reactions with these nucleophiles have met with limited success [32][33][34][35][36][37][38][39]. In terms of enantioselective catalytic strategies, Kobayashi has reported the conjugate addition of azlactones to acrylates using a calcium pybox complex, but with enantioselectivities

A study on selective transformation of norbornadiene into fluorinated cyclopentane-fused isoxazolines

• Zsanett Benke,
• Attila M. Remete and
• Loránd Kiss

Beilstein J. Org. Chem. 2021, 17, 2051–2066, doi:10.3762/bjoc.17.132

• the selectivity of olefin bonds during a CM reaction [38][39][40][41][42][43]. Investigations of various types of olefins in CM, such as substituted and functionalized styrenes, unsaturated tertiary alcohols, olefins with quaternary carbon centers, acrylates, allyl ethers or allyl acetates gave a

• number of fluorine-containing alkenes (Figure 3). Compounds 7a and 7b as well as 7f–h were type I olefins, while acrylate esters 7c–e were type II olefins. Because 1st generation metathesis catalysts usually perform poorly in CM reactions with acrylates [31][32][36][39][41], only G-2, HG-2 and G-3 were

Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• anthracene derivatives 33. The strategy involved a palladium(II)-catalyzed tandem transformation with diphenyl carboxylic acids 31 and acrylates 32 (Scheme 7) [41]. This new methodology involved a carboxyl-directed C–H alkenylation, a carboxyl-directed secondary C–H activation, an intramolecular C–C-bond

• ] cyclotrimerization reactions with bis(trimethylsilyl)acetylene (23). [2 + 2 + 2] Alkyne-cyclotrimerization reactions catalyzed by a CoCl2·6H2O/Zn reagent. Pd(II)-catalyzed sp3 C–H alkenylation of diphenyl carboxylic acids with acrylates. Pd(II)-catalyzed sp3 C–H arylation with o-tolualdehydes and aryl iodides

Electron-rich triarylphosphines as nucleophilic catalysts for oxa-Michael reactions

• Susanne M. Fischer,
• Simon Renner,
• A. Daniel Boese and
• Christian Slugovc

Beilstein J. Org. Chem. 2021, 17, 1689–1697, doi:10.3762/bjoc.17.117

• slightly lower than the activity of the methoxy-substituted congeners. As an example for acrylates as Michael acceptors, the performance of the catalysts in the oxa-Michael addition polymerization of 2-hydroxyethyl acrylate (HEA, 4) was investigated [27][28][29]. The catalyst loading was increased to 5 mol

• 13C NMR spectrum of poly4 (see Supporting Information File 1) and its share is with approximately 17–20% higher in polymers prepared at 80 °C (Figure 2). The formation of this repeat unit consumes two equivalents of acrylates and thus, disproportionally decreases the quantity of acrylate groups in

Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

• Thiago S. Silva and
• Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

• more probable than the ET proposal, especially for radicals derived from alkyl radical additions to acrylates due to their lower oxidation potentials toward the Fe(II) species [81]. The methodology developed by Baran had a rapid impact on the organic synthesis community, and numerous examples of this

Synthetic reactions driven by electron-donor–acceptor (EDA) complexes

• Zhonglie Yang,
• Yutong Liu,
• Kun Cao,
• Xiaobin Zhang,
• Hezhong Jiang and
• Jiahong Li

Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67

• trifluoromethylation (Scheme 25). A variety of olefins, such as ene carbamates, styrene, aliphatic olefins, vinyl ethers, and acrylates are compatible in this approach, affording corresponding β-(trifluoromethyl)alkynes with good to excellent yield. The bifunctionalization was achieved by an EDA-complex-initiated