Search results

Search for "organocatalytic" in Full Text gives 179 result(s) in Beilstein Journal of Organic Chemistry.

Graphical Abstract
  • amorph-4-ene-10β-ol known from plants. A short synthesis using an organocatalytic approach through a tandem Mannich/intramolecular Diels–Alder reaction led to a mixture of cadinols, which was used for the assignment of the natural cadinol structures and their stereoisomers. Keywords: Anura; chiral gas
PDF
Album
Supp Info
Full Research Paper
Published 16 Feb 2023

Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles

  • Bilge Banu Yagci,
  • Selin Ezgi Donmez,
  • Onur Şahin and
  • Yunus Emre Türkmen

Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6

Graphical Abstract
  • enantioselective organocatalytic aza-Nazarov cyclization affording six-membered heterocycles after a ring expansion of the cyclization products [22]. Rasapalli and co-workers recently developed an efficient aza-Nazarov cyclization of quinazolinonyl enones promoted by TfOH or MsOH (methanesulfonic acid) for the
PDF
Album
Supp Info
Full Research Paper
Published 17 Jan 2023

Total synthesis of grayanane natural products

  • Nicolas Fay,
  • Rémi Blieck,
  • Cyrille Kouklovsky and
  • Aurélien de la Torre

Beilstein J. Org. Chem. 2022, 18, 1707–1719, doi:10.3762/bjoc.18.181

Graphical Abstract
  • synthetic route based on a convergent strategy to accomplish the synthesis of principinol E, grayanotoxin III and rhodomollein XX [34]. The key steps include i) a tandem reaction combining organocatalytic Mukaiyama aldol and intramolecular Hosomi–Sakurai reactions in a one-pot manner; ii) a 7-membered
PDF
Album
Review
Published 12 Dec 2022

Polymer and small molecule mechanochemistry: closer than ever

  • José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128

Graphical Abstract
  • organocatalytic units embedded in polymers for catalysis in small molecule systems have been discussed [15][19][20]. Moreover, the ability of force to deform the reaction energy landscape and modulate the reversibility of the reactions within proteins has been demonstrated. For example, mechanical force was used
PDF
Album
Perspective
Published 14 Sep 2022

Bioinspired tetraamino-bisthiourea chiral macrocycles in catalyzing decarboxylative Mannich reactions

  • Hao Guo,
  • Yu-Fei Ao,
  • De-Xian Wang and
  • Qi-Qiang Wang

Beilstein J. Org. Chem. 2022, 18, 486–496, doi:10.3762/bjoc.18.51

Graphical Abstract
  • cavity could resemble the circumstance of the catalytic triad of Polyketide synthases (PKSs) [40][41][42] (Figure 1). On the other hand, the organocatalytic asymmetric decarboxylative addition reactions of MAHTs to imines provide an efficient means for accessing valuable chiral β-amino esters [43][44][45
PDF
Album
Supp Info
Full Research Paper
Published 02 May 2022

New advances in asymmetric organocatalysis

  • Radovan Šebesta

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

Graphical Abstract
  • within the area. Organocatalytic reactions are highly suitable components of cascade transformations as exemplified by the seminal work of Enders [13]. Besides traditional enamine and iminium activation of carbonyl compounds other activation modes were uncovered which significantly broadened the
  • asymmetric organocatalytic methods to assemble biologically relevant compounds is highlighted by a review article devoted to the syntheses of coumarin derivatives [16]. Conjugated additions of stabilized nucleophiles are the cornerstone of organocatalytic methodology. Recent advances in this area are covered
PDF
Editorial
Published 28 Feb 2022

Organocatalytic asymmetric nitroso aldol reaction of α-substituted malonamates

  • Ekta Gupta,
  • Narendra Kumar Vaishanv,
  • Sandeep Kumar,
  • Raja Krishnan Purshottam,
  • Ruchir Kant and
  • Kishor Mohanan

Beilstein J. Org. Chem. 2022, 18, 217–224, doi:10.3762/bjoc.18.25

Graphical Abstract
  • takes place to afford the nitroso aldol product. Conclusion In summary, an efficient organocatalytic asymmetric nitroso aldol reaction of α-methylmalonamate has been reported. The reaction utilizes the well-known Takemoto catalyst, and this protocol demonstrates for the first time the use of malonamate
PDF
Album
Supp Info
Letter
Published 21 Feb 2022

Asymmetric organocatalytic Michael addition of cyclopentane-1,2-dione to alkylidene oxindole

  • Estelle Silm,
  • Ivar Järving and
  • Tõnis Kanger

Beilstein J. Org. Chem. 2022, 18, 167–173, doi:10.3762/bjoc.18.18

Graphical Abstract
  • molecular complexity. There are many examples of the organocatalytic synthesis of fused cycles starting from the cyclohexane-1,3-dione. For example, Rueping et al. demonstrated that the cyclohexane-1,3-dione undergoes a cascade reaction with α,β-unsaturated aldehydes [4] and they later employed the method
  • using CPD as a precursor for high value-added fine chemicals such as a homocitric acid lactone was published by our group [19]. Since then we have developed synthetic pathways for lycoperdic acid [20] and nucleoside analogues [21] starting from CPD. The organocatalytic methods for the synthesis of
  • malonates [25]. Herein, we report the results of an asymmetric organocatalytic Michael addition of CPD to alkylidene oxindoles. Results and Discussion Chiral multifunctional thioureas [26][27] and squaramides [28] are extensively used as catalysts in asymmetric Michael additions. We believed that a
PDF
Album
Supp Info
Full Research Paper
Published 03 Feb 2022

Chemoselective N-acylation of indoles using thioesters as acyl source

  • Tianri Du,
  • Xiangmu Wei,
  • Honghong Xu,
  • Xin Zhang,
  • Ruiru Fang,
  • Zheng Yuan,
  • Zhi Liang and
  • Yahui Li

Beilstein J. Org. Chem. 2022, 18, 89–94, doi:10.3762/bjoc.18.9

Graphical Abstract
  • of the N(sp2)–H bond by using a catalytic amount of DBU for the preparation of indoleamides [14] (Scheme 1, A2). Subsequently, Sundén reported an efficient chemoselective method for the synthesis of indoleamide by oxidative organocatalytic reaction of indole derivatives and conjugated aldehydes under
PDF
Album
Supp Info
Full Research Paper
Published 10 Jan 2022

Bifunctional thiourea-catalyzed asymmetric [3 + 2] annulation reactions of 2-isothiocyanato-1-indanones with barbiturate-based olefins

  • Jiang-Song Zhai and
  • Da-Ming Du

Beilstein J. Org. Chem. 2022, 18, 25–36, doi:10.3762/bjoc.18.3

Graphical Abstract
  • strategy to construct a series of spirobarbiturates derived from indanone. Combining current researches of these two compounds, we report the first organocatalytic asymmetric Michael addition/cyclization reaction between barbituric acid-derived olefins and indanones (Scheme 1b). Under the action of the
  • organocatalytic domino Michael/cyclization reaction. This annulation reaction can be easily performed under air atmosphere and mild conditions with 5 mol % catalyst loading. By using bifunctional thiourea catalyst, a series of structurally diverse indanone-derived spirobarbiturates could be obtained in high
PDF
Album
Supp Info
Full Research Paper
Published 04 Jan 2022

Highly stereocontrolled total synthesis of racemic codonopsinol B through isoxazolidine-4,5-diol vinylation

  • Lukáš Ďurina,
  • Anna Ďurinová,
  • František Trejtnar,
  • Ľuboš Janotka,
  • Lucia Messingerová,
  • Jana Doháňošová,
  • Ján Moncol and
  • Róbert Fischer

Beilstein J. Org. Chem. 2021, 17, 2781–2786, doi:10.3762/bjoc.17.188

Graphical Abstract
  • the proline catalysis are of higher purity (after purification by silica gel column chromatography), than those synthesized by other methods [16]. Definitely, the effective asymmetric organocatalytic conjugate additions of hydroxylamines to enals using various catalysts provide access to
  • racemic codonopsinol B (1) and its N-nor-methyl analogue 2 starting from achiral materials. Four consecutive stereocenters in the target molecules were accomplished sequentially by the organocatalytic aza-Michael addition of N-Cbz-protected hydroxylamine to (E)-4-methoxycinnamaldehyde, the trans
PDF
Album
Supp Info
Full Research Paper
Published 24 Nov 2021

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

Graphical Abstract
  • functional calculations showed that the chiral phosphoric acid proton forms an H-bond with nitrogen atoms of 1 and the phosphate acts as a chiral counterion, resulting in a [3,3]-sigmatropic rearrangement with controlled stereoselectivity [14][41]. In 2017, Tan and co-workers developed an organocatalytic
  • ]. Organocatalytic aryl C–H activation via a nonradical process represents an enormous challenge in organic synthesis, although the nucleophilic aromatic substitution with cleavage of the electrophilic aryl C–H bond has only recently been developed by transition-metal-catalyzed aryl C–H activation [57]. In the
  • -workers showed that azo groups enable the organocatalytic asymmetric arylation of indoles. The nucleophilic aromatic substitution between the azobenzene derivative 24 and indoles 25 was carried out in the presence of 2.5 mol % chiral phosphoric acid (CPA 8, Scheme 9a), leading to the intermediate I-4
PDF
Album
Review
Published 15 Nov 2021

Solvent-free synthesis of enantioenriched β-silyl nitroalkanes under organocatalytic conditions

  • Akhil K. Dubey and
  • Raghunath Chowdhury

Beilstein J. Org. Chem. 2021, 17, 2642–2649, doi:10.3762/bjoc.17.177

Graphical Abstract
  • -nitrosilanes through a Cu(II)–chiral bipyridine complex catalyzed enantioselective silyl transfer reaction to nitroalkenes using Suginome’s silylboron reagent (Scheme 1a) [28]. Recently, we have reported the synthesis of chiral β-nitrosilanes via an organocatalytic conjugate addition of nitromethane to β
  • nucleophiles to β-silyl α,β-unsaturated carbonyl compounds were documented as one of the straightforward and atom-economic approaches for the facile synthesis of chiral organosilanes (Scheme 1c–f) [30][31][32][33]. Recently, the aforementioned reaction under organocatalytic conditions has gained attention [34
  • to moisture and air. Therefore, this method offers an attractive and robust option for the preparation of chiral β-silyl nitroalkanes. In sharp contrast to the aforesaid reaction, organocatalytic conjugate addition reactions of nitroalkanes to enones have been well studied [39][40][41][42][43]. To
PDF
Album
Supp Info
Full Research Paper
Published 27 Oct 2021

N-Sulfinylpyrrolidine-containing ureas and thioureas as bifunctional organocatalysts

  • Viera Poláčková,
  • Dominika Krištofíková,
  • Boglárka Némethová,
  • Renata Górová,
  • Mária Mečiarová and
  • Radovan Šebesta

Beilstein J. Org. Chem. 2021, 17, 2629–2641, doi:10.3762/bjoc.17.176

Graphical Abstract
  • organocatalytic transformations were successfully performed under solvent-free ball-milling conditions [30][31]. In this context, we describe the synthesis of new pyrrolidine appended sulfinylurea and thiourea organocatalysts and their assessment in Michael additions of aldehydes to nitroalkenes. Furthermore, we
  • of the catalysts in organocatalytic Michael addition and suggested the possibilities of further improvement in catalyst design. Experimental Synthesis of catalysts (S)-tert-Butyl 2-(aminomethyl)pyrrolidine-1-carboxylate (2) The solution of PPh3 (1.64 g, 6.3 mmol) and N-Boc-(S)-prolinol (1, 1.0 g, 5.0
PDF
Album
Supp Info
Full Research Paper
Published 25 Oct 2021

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

  • Pratibha Sharma,
  • Raakhi Gupta and
  • Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

Graphical Abstract
  • be accessed from the chiral pool. Both types of organocatalysts, namely those acting through non-covalent bonding as well as those working by making covalent bonding have been employed for accomplishing asymmetric aza-MRs. There are several review articles available on organocatalytic asymmetric aza
  • . Review In the present review, the known stereoselective syntheses of pharmacology-oriented nitrogen containing heterocyclic scaffolds via non-covalent bonding and covalent bonding organocatalytic aza-MRs has been systematized. This classification is especially useful for researchers to understand both
  • compounds; however, in order to comply with the requirements of a mini review, additions of amines and amides only will be included. 1. Non-covalent bonding organocatalytic aza-Michael reactions Organocatalysts catalyzing aza-MRs through mainly hydrogen bonding include cinchona alkaloids, squaramide
PDF
Album
Review
Published 18 Oct 2021

Enantioselective PCCP Brønsted acid-catalyzed aminalization of aldehydes

  • Martin Kamlar,
  • Robert Reiberger,
  • Martin Nigríni,
  • Ivana Císařová and
  • Jan Veselý

Beilstein J. Org. Chem. 2021, 17, 2433–2440, doi:10.3762/bjoc.17.160

Graphical Abstract
  • organocatalytic synthesis of molecules with this moiety uses the reaction between aldehydes and anthranilamide building blocks. The advantage of this methodology lies in the fact that both starting materials are readily available, and the enantioselectivity of such cyclization reactions can be controlled by
  • configuration of aminals obtained by List and co-workers [14]. Conclusion In summary, we have reported an organocatalytic asymmetric aminalization reaction between aldehydes and anthranilamides catalyzed by a PCCP catalyst as a cheap and readily available option to conventional chiral BINOL phosphoric acids
PDF
Album
Supp Info
Full Research Paper
Published 16 Sep 2021

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

Graphical Abstract
  • electrophilic and nucleophilic α-functionalizations are possible, whereas with the use of α,β-unsaturated aldehydes the β-position is functionalized with nucleophiles and the γ-position with electrophiles. In this sense, Jørgensen and colleagues have developed the first organocatalytic asymmetric Michael
  • acid (4) as catalyst [30]. Based on this pioneer work, our research group described an efficient, highly stereoselective, one-pot process comprising an organocatalytic conjugate addition of dimedone or 4-hydroxycoumarin 1 to α,β-unsaturated aldehydes 2 followed by an intramolecular isocyanide-based
  • the desired transformation by using only one catalyst [70]. In this sense, an efficient asymmetric organocatalytic reaction was reported by Zhang et al. for the synthesis of 2,8-dioxabicyclo[3.3.1]nonanes [71]. A combination of catalysts 7 and 110, involving iminium and anion-binding catalysis
PDF
Album
Review
Published 03 Aug 2021

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

Graphical Abstract
  • 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
  • -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
  • the keto group [11][12][13]. Consequently, our group developed an organocatalytic asymmetric Michael–acyl transfer reaction of α-nitroketones with unsaturated pyrazolones, 2-hydroxycinnamaldehydes, γ/δ-hydroxyenones, o-quinone methides, etc. [14][15][16][17][18]. Other groups also contributed
PDF
Album
Supp Info
Full Research Paper
Published 14 Jun 2021

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

  • Guido Gambacorta,
  • James S. Sharley and
  • Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Graphical Abstract
PDF
Album
Review
Published 18 May 2021

Nitroalkene reduction in deep eutectic solvents promoted by BH3NH3

  • Chiara Faverio,
  • Monica Fiorenza Boselli,
  • Patricia Camarero Gonzalez,
  • Alessandra Puglisi and
  • Maurizio Benaglia

Beilstein J. Org. Chem. 2021, 17, 1041–1047, doi:10.3762/bjoc.17.83

Graphical Abstract
  • mixture [14]. Results and Discussion Based on our previous experiences with organocatalytic reactions in alternative, biodegradable solvents [15][16], and following some preliminary investigations on the physicochemical properties of several DES combinations, for this application, we decided to focus our
PDF
Album
Supp Info
Letter
Published 06 May 2021

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

Graphical Abstract
  • interest in compound 2, we thus thought about developing an alternative organocatalytic kinetic resolution protocol to control the esterification of rac-2. Chiral isothioureas (ITUs) emerged as easily available and powerful catalysts for numerous applications [29][30][31][32] and have been very
PDF
Album
Supp Info
Letter
Published 08 Apr 2021

Synthesis of β-triazolylenones via metal-free desulfonylative alkylation of N-tosyl-1,2,3-triazoles

  • Soumyaranjan Pati,
  • Renata G. Almeida,
  • Eufrânio N. da Silva Júnior and
  • Irishi N. N. Namboothiri

Beilstein J. Org. Chem. 2021, 17, 762–770, doi:10.3762/bjoc.17.66

Graphical Abstract
  • functionalization of triazoles under metal-free conditions has been reported. These include the Broensted acid-catalysed N2 alkylation [27], organocatalytic N1 alkylation [28][29], N2-arylation using hypervalent iodine (Scheme 1c) [30], N2-alkylation involving radical intermediate [31], pyridine-N-oxide-mediated N1
PDF
Album
Supp Info
Letter
Published 31 Mar 2021

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

Graphical Abstract
  • irradiation [118], oxidation [119] or acidic degradation [120]. It is worth mentioning that organocatalytic depolymerisation methods have also been reported [121][122]. Despite these systems represent promising “greener” options, they still are in an early development stage. Uses are mainly limited to
PDF
Album
Review
Published 02 Mar 2021
Graphical Abstract
  • -Michael addition (SMA) reactions remain a rather less explored reaction among asymmetric organocatalytic transformations, mainly because of the high nucleophilicity of thiols causing difficulties in controlling the stereoselectivity [21], despite C–S bond-forming reactions are of great interest in
  • product was ultimately obtained at room temperature (83% ee, Table 2, entry 3). The absolute configuration of the product was assigned as “S” by comparing the obtained optical rotation value with the values in the literature for the organocatalytic SMA of thiols to trans-chalcone derivatives [29][42]. A
  • conclusion, we report the enantioselective organocatalytic sulfa-Michael addition reaction of naphthalene-1-thiol to trans-chalcones, in the presence of a new bifunctional quinine derived sulfonamide organocatalyst. The adducts obtained with moderate to excellent ee values are β-naphthyl-β-sulfanyl ketones
PDF
Album
Supp Info
Full Research Paper
Published 18 Feb 2021

Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

  • Vladimir Kubyshkin,
  • Rebecca Davis and
  • Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40

Graphical Abstract
  • proline generally being among the first structures in this list [20]. It is possible that the initial role of proline was metabolic or based on its organocatalytic features that were essential for the development of primitive molecular life [21]. Furthermore, such an evolution model suggests that the
PDF
Album
Review
Published 15 Feb 2021
Other Beilstein-Institut Open Science Activities