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

• synthesis of carbonates from CO2 [24][25][26] and the synthesis of oxazolidines from isocyanates and epoxides [27]. Furthermore, their application in primary hydroxy group selective acylation of diols [28] and their use as organophotoredox catalysts [29][30] is known. The latter mentioned catalysts are

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• and proceeds through a by base-promoted annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates. The reaction mechanism of this formal [4 + 3] annulation includes the in situ generated allylic ylide, nucleophilic substitution, Michael additon, and elimination processes

• the synthesis of spirooxindole derivatives continues to be a highly active subject in organic synthesis [31][32][33][34][35]. In recent years, the readily available isatin-derived Morita–Baylis–Hillman (MBH) carbonates have become one of the most powerful reagents for the construction of diverse

• spirooxindoles [36][37][38][39][40][41][42][43]. In the presence of Lewis bases, isatin-derived MBH carbonates usually undergo [3 + 2] and [3 + 3] cycloaddition reactions with a broad range of active C–C and C–N double bonds and 1,3-dipolarpohiles to give various five- or six-membered cyclic spirooxindoles [44

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

• Morita–Baylis–Hillman carbonates from isatins by using a Lewis base catalytic system (Scheme 52) [84]. Screening several organocatalysts showed that the 1,3-oxo-ethynylation of starting materials with silylethynyl-1,2-benziodoxol-3(1H)-ones 123 was obtained by using catalyst N, while 1,3

• conjugate Lewis base Brønsted acid catalyst. Sulfenylation of deconjugated butyrolactams. Intramolecular sulfenofunctionalization of alkenes with phenols. Organocatalytic 1,3-difunctionalizations of Morita–Baylis–Hillman carbonates. Organocatalytic sulfenylation of β‑naphthols. Acid-promoted

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

• –Cu(I) complexes 12 (Scheme 5). A variety of bases, namely metal alkoxides, alkali metal carbonates, n-butyllithium, and lithium bis(trimethylsilyl)amide have been employed for this purpose. In 2010, Diez-González et al. synthesized a variety of NHC–Cu(I) complexes 14 from imidazolium salts 13 using

• + 2] cycloaddition of azides with alkynes as will be discussed later. Jin Zhang et al. used the same base, namely KOt-Bu in the presence of CuCl to obtain the thiazolylidene–Cu(I) complex 20 (Scheme 10) [23]. In 2012, Zhu and co-workers synthesized NHC–CuCl complexes using alkali carbonates (Na2CO3

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

Group 13 exchange and transborylation in catalysis

• Dominic R. Willcox and
• Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

• esters, lactones, and carbonates with HBpin under microwave irradiation (Scheme 13) [57]. When HBpin and boric acid were reacted together, BH3-coordinated HBpin and O(Bpin)2 were detected by 11B NMR spectroscopy. Supported by computational analysis and single-turnover experiments, the reaction was

• carbonates and the proposed mechanism. H-B-9-BBN-catalysed reductive aldol-type reaction and the proposed mechanism. H-B-9-BBN-catalysed diastereoselective allylation of ketones and the Ph-BBD-catalysed enantioselective allylation of ketones and the proposed mechanism. H-B-9-BBN-catalysed C–F arylation of

Synthetic study toward tridachiapyrone B

• Morgan Cormier,
• Florian Hernvann and
• Michaël De Paolis

Beilstein J. Org. Chem. 2022, 18, 1741–1748, doi:10.3762/bjoc.18.183

• allyltitanocene reagents to carbonyl compounds was described by Sato which were prepared from the corresponding allyl carbonates exposed to the combination of [Cp2TiCl2]/n-BuLi [40]. Pleasingly, conducting the coupling of carbonate 20 to 5 in conditions inspired from Carreira’s study (Scheme 7b) led to the

A trustworthy mechanochemical route to isocyanides

• Francesco Basoccu,
• Federico Cuccu,
• Federico Casti,
• Rita Mocci,
• Claudia Fattuoni and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 732–737, doi:10.3762/bjoc.18.73

• mg of NaCl as a grinding auxiliary (0.5 h, 36 Hz, Table S1 in Supporting Information File 1). So, we then looked for a solid base to use in place of triethylamine, avoiding the use of further additives. Unluckily, neither solid inorganic bases such Na, K, and Cs carbonates [37], Mg and Ba oxides, nor

Synthesis of sulfur karrikin bioisosteres as potential neuroprotectives

• Martin Pošta,
• Václav Zima,
• Lenka Poštová Slavětínská,
• Marika Matoušová and
• Petr Beier

Beilstein J. Org. Chem. 2022, 18, 549–554, doi:10.3762/bjoc.18.57

• was treated with triethylamine in order to obtain the eliminated product exclusively. The second elimination over C4–C5 resulted in a low yield of 26 (41%) (not shown in Scheme 5) and a high (Ph3P)4Pd catalyst load (10%) was necessary, despite the fact that allylic carbonates are good substrates in

Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• highly selective hydration/acylation of tertiary bromopropargylic alcohols with carboxylic acids promoted by alkali metal carbonates [24]. The reaction proceeds via the ring-opening of 1,3-dioxolan-2-one intermediates formed with hydroxy and alkynyl groups of bromopropargylic alcohol and alkali metal

Regioselectivity of the S_EAr-based cyclizations and S_EAr-terminated annulations of 3,5-unsubstituted, 4-substituted indoles

• Jonali Das and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2022, 18, 293–302, doi:10.3762/bjoc.18.33

• constructing carbon–carbon and carbon–heteroatom bonds in organic synthesis [8][9][10]. In the course of their diversity-oriented synthesis of indole-based peri-annulated compounds, You and co-workers in 2013 reported the intramolecular Tsuji–Trost reaction of indolyl allyl carbonates 1 under the catalysis of

• or annulation of: (A) substituted arenes/heteroarenes and (B) 3,5-unsubstituted, 4-substituted indoles. Indole C3 regioselective intramolecular alkylation of indolyl allyl carbonates. Indole C3 regioselective Michael-type cyclization in the total synthesis of (−)-indolactam V. Synthesis of azepino

Direct C(sp³)–H allylation of 2-alkylpyridines with Morita–Baylis–Hillman carbonates via a tandem nucleophilic substitution/aza-Cope rearrangement

• Siyu Wang,
• Lianyou Zheng,
• Shutao Wang,
• Shulin Ning,
• Zhuoqi Zhang and
• Jinbao Xiang

Beilstein J. Org. Chem. 2021, 17, 2505–2510, doi:10.3762/bjoc.17.167

• (sp3)–H allylic alkylation of 2-alkylpyridines with Morita–Baylis–Hillman (MBH) carbonates is described. A plausible mechanism of the reaction might involve a tandem SN2’ type nucleophilic substitution followed by an aza-Cope rearrangement. Various alkyl substituents on 2-alkylpyridines were tolerated

• ; Morita–Baylis–Hillman carbonates; Introduction Pyridines are among the most important heterocyclic structural moieties in many biologically active natural products, pharmaceuticals, and agrochemicals [1][2][3]. Therefore, the development of efficient strategies for functionalized pyridine derivatives

• synergistic catalyzed allylic alkylation between electron-deficient 2-ethyl benzoxazoles and MBH carbonates by the combination of a Lewis base and a metal salt [24]. In their studies, although pyridine derivatives were also applicable in the reaction, the presence of a strong electron-withdrawing NO2 group

Copper-catalyzed monoselective C–H amination of ferrocenes with alkylamines

• Zhen-Sheng Jia,
• Qiang Yue,
• Ya Li,
• Xue-Tao Xu,
• Kun Zhang and
• Bing-Feng Shi

Beilstein J. Org. Chem. 2021, 17, 2488–2495, doi:10.3762/bjoc.17.165

• ferrocenes with alkynes by using an unprecedented half-sandwich Sc catalyst [36]. Very recently, Shi and Zhang demonstrated a Cp*Co-catalyzed ortho-C–H allylation of ferrocenes assisted by thioamide using allyl carbonates and vinylcyclopropanes as allylating partners [37]. Meanwhile, Zhang and co-authors

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

• propargylic carbonates 113 with terminal alkynes 114. The scope of this reaction consisted of 12 examples that were synthesized in moderate to good yields (40–87%). The authors obtained the best yields by using electron-deficient aryl alkynes or secondary carbonates with electron-rich arene substituents (115a

• anthracenes from a bifunctional organomagnesium alkoxide. Palladium-catalyzed tandem C–H activation/bis-cyclization of propargylic carbonates. Ruthenium-catalyzed C–H arylation of acetophenone derivatives with arenediboronates. Pd-catalyzed intramolecular cyclization of (Z,Z)-p-styrylstilbene derivatives

Asymmetric organocatalyzed synthesis of coumarin derivatives

• Natália M. Moreira,
• Lorena S. R. Martelli and
• Arlene G. Corrêa

Beilstein J. Org. Chem. 2021, 17, 1952–1980, doi:10.3762/bjoc.17.128

• described an allylic alkylation reaction between 3-cyano-4-methylcoumarins 39 and Morita–Baylis–Hillman (MBH) carbonates 40 [45]. In this case, the catalyst (DHQ)2PYR 42 activates the MBH substrate and generates the dienolate in the vinylogous coumarin moiety, acting as a base. After the nucleophilic

• reaction between 3-cyano-4-methylcoumarins 39 and MBH carbonates 40. Enantioselective synthesis of cyclopropa[c]coumarins 45. NHC-catalyzed lactonization of 2-bromoenals 46 with 4-hydroxycoumarin (1). NHC-catalyzed enantioselective synthesis of dihydrocoumarins 51. Domino reaction of enals 2 with

Sustainable manganese catalysis for late-stage C–H functionalization of bioactive structural motifs

• Jongwoo Son

Beilstein J. Org. Chem. 2021, 17, 1733–1751, doi:10.3762/bjoc.17.122

• peptide, which can be further utilized as a Michael acceptor for a variety of nucleophiles. Based on their manganese-catalyzed allylation using Morita–Baylis–Hillman carbonates, the Ackermann group established an applicable late-stage C–H glycosylation of peptides (Scheme 12) [95]. Thus, allylative

• peptide–carbohydrate conjugation was achieved using tryptophan-containing peptides 29 and sugar-containing allyl carbonates 30 in chemo- and site-selective manners using a pyridyl directing group. The optimized reaction conditions entailed the use of dimanganese decacarbonyl as the catalyst and sodium

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

• Pezhman Shiri,
• Ali Mohammad Amani and
• Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

• after the support of DOX molecules on the polymer prodrug, which resulted in reduced side effects (Scheme 18b) [48][49]. Cu-catalyzed synthesis of fully decorated triazoles The Cu-catalyzed regioselective cyclization of alkynes 57 and azides 58, followed by coupling with propargylic carbonates 59

• , afforded the corresponding 5-allenyl-1,2,3-triazoles 60 in moderate to excellent yield. The reaction was tolerant to the presence of a range of aryl-, alkyl-, and heteroaryl-substituted alkynes as well as aryl and alkyl azides. Subsequently, the scope of propargylic carbonates was further explored

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

Unexpected rearrangements and a novel synthesis of 1,1-dichloro-1-alkenones from 1,1,1-trifluoroalkanones with aluminium trichloride

• Beatrice Lansbergen,
• Catherine S. Meister and
• Michael C. McLeod

Beilstein J. Org. Chem. 2021, 17, 404–409, doi:10.3762/bjoc.17.36

• dichloroalkenes [18][19][20]. The preparation of 1,1-dichloro-1-alkenes from hydrazones [21] and from 2,2,2-trichloroethyl carbonates [22] has also been reported. Internal difluoroalkanes have been used to generate chloroalkene products using AlEt2Cl [23][24]. In this article we describe the AlCl3-mediated

Natural dolomitic limestone-catalyzed synthesis of benzimidazoles, dihydropyrimidinones, and highly substituted pyridines under ultrasound irradiation

• Kumar Godugu,
• Venkata Divya Sri Yadala,
• Mohammad Khaja Mohinuddin Pinjari,
• Trivikram Reddy Gundala,
• Lakshmi Reddy Sanapareddy and
• Chinna Gangi Reddy Nallagondu

Beilstein J. Org. Chem. 2020, 16, 1881–1900, doi:10.3762/bjoc.16.156

• in Figure 3. In the IR spectrum, two distinct vibrational modes of the carbonates, i.e., out-of-plane bending and in-plane bending, were observed at 875 cm−1 (ν2) and 720 cm−1 (ν4), respectively. The bands at 1086 cm−1 and 1424 cm−1 were ascribed to a symmetric stretching vibration (ν1) and an

One-pot synthesis of oxazolidinones and five-membered cyclic carbonates from epoxides and chlorosulfonyl isocyanate: theoretical evidence for an asynchronous concerted pathway

• Esra Demir,
• Ozlem Sari,
• Yasin Çetinkaya,
• Ufuk Atmaca,
• Safiye Sağ Erdem and
• Murat Çelik

Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148

• phenyl, benzyl and fused cyclic alkyl groups in different solvents under mild reaction conditions without additives and catalysts was studied. Oxazolidinones and five-membered cyclic carbonates were obtained in ratios close to 1:1 in the cyclization reactions. The best yields of these compounds were

• obtained in dichloromethane (DCM). Together with 16 known compounds, two novel oxazolidinone derivatives and two novel cyclic carbonates were synthesized with an efficient and straightforward method. Compared to the existing methods, the synthetic approach presented here provides the following distinct

• . The further investigation of the potential energy surfaces associated with two possible channels leading to oxazolidinones and five-membered cyclic carbonates disclosed that the cycloaddition reaction proceeds via an asynchronous concerted mechanism in gas phase and in DCM. Keywords: chlorosulfonyl

Activated carbon as catalyst support: precursors, preparation, modification and characterization

• Melanie Iwanow,
• Tobias Gärtner,
• Volker Sieber and
• Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

• of hydrogen and metal carbonates as well as metallic metal or M2O (M = Na or K). The absence of carbon dioxide at these temperatures suggests that the carbonates are not formed by reaction of hydroxides with CO2. At higher temperatures, CO and CO2 were found due to the decomposition of the metal

• carbonates. Moreover, they found that no porosity of the resulting materials was formed by using a metal carbonate instead of hydroxide as activation reagent [8][14]. Pis and co-workers used the TPD method for evaluation of the thermal stability of introduced nitrogen functionalities by modification with

• lignocellulosic precursor with KOH by XPS. They observed that the oxygen on the surface of the material is associated with potassium as carbonates or oxides [131]. Cordero and co-workers observed by XPS that different amounts and species of nitrogen-containing surface groups are obtained by HNO3 treatment of

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• formations of enantioenriched α-substituted allylic boronates take place in high yields and site-selectivity (>98% SN2′) starting with either trans- or cis-disubstituted alkenes 313, as well as linear or branched alkyl and aryl trisubstituted allylic carbonates 314. The further oxidation of the boronated

• carbonates to deliver the targeted products (Scheme 51) [94]. In addition to allylic carbonates, allylic acetals (319) were also used for C–B bond formation that, in the presence of CuCl/(R,R)-BenzP* and stoichiometric amounts of KO-t-Bu, provide access to α-chiral linear or carbocyclic (γ-alkoxyallylic

Allylic cross-coupling using aromatic aldehydes as α-alkoxyalkyl anions

• Akihiro Yuasa,
• Kazunori Nagao and
• Hirohisa Ohmiya

Beilstein J. Org. Chem. 2020, 16, 185–189, doi:10.3762/bjoc.16.21

• . The synergistic palladium/copper-catalyzed reaction of aromatic aldehydes, allylic carbonates, and a silylboronate produces the corresponding homoallylic alcohol derivatives. This process involves the catalytic formation of a nucleophilic α-silyloxybenzylcopper(I) species and the subsequent palladium

• electrophile [8][10][11]. This paper describes in full detail the racemic system using allylic carbonates. The allylic cross-coupling of aromatic aldehydes and allylic carbonates with a silylboronate by the merging of a copper–N-heterocyclic carbene catalyst and a palladium–bisphosphine catalyst produced

• and allylic carbonates 2. Methyl, tert-butyl and fluoro substituents were tolerated at the ortho- or para-positions of the aromatic aldehyde (3ba–da). 2,6-Dimethylphenyl- or 1-naphthyl moieties as the γ-substituent of the primary allylic carbonate were tolerated in the reaction (3ab and 3ac). Cinnamyl

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

• -linear ratios and enantioselectivities. In 2013, Gouverneur and co-workers [94] demonstrated the regio and stereocontrolled fluorination of allylic carbonates with [Ir(COD)Cl]2 as the catalyst and TBAF(t-BuOH)4 as the fluoride source to produce branched and linear allylic fluorides (Scheme 46