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Search for "Mannich reaction" in Full Text gives 72 result(s) in Beilstein Journal of Organic Chemistry.

Asymmetric Mannich reactions of (S)-N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimines with yne nucleophiles

  • Ziyi Li,
  • Li Wang,
  • Yunqi Huang,
  • Haibo Mei,
  • Hiroyuki Konno,
  • Hiroki Moriwaki,
  • Vadim A. Soloshonok and
  • Jianlin Han

Beilstein J. Org. Chem. 2020, 16, 2671–2678, doi:10.3762/bjoc.16.217

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  • afford diastereomerically pure compounds. The purified Mannich addition products were deprotected to give the target enantiomerically pure trifluoromethylpropargylamines. A mechanistic rationale for the observed stereochemical outcome is discussed. Keywords: arylethynes; asymmetric Mannich reaction; C
  • compounds for the synthesis of biologically relevant targets and their self-disproportionation of enantiomers (SDE) properties [58][59][60] are currently under study and will be reported in due course. Experimental General procedure for the Mannich reaction of arylethynes with sulfinylimine: Into an oven
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Published 29 Oct 2020

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

  • Rodrigo Costa e Silva,
  • Luely Oliveira da Silva,
  • Aloisio de Andrade Bartolomeu,
  • Timothy John Brocksom and
  • Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

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Published 06 May 2020
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  • effect on stability and ordering, and, additionally we aimed to test the possibility of formation of water-soluble capsules, which are of particular interest to supramolecular chemists. Results and Discussion RSAs can be readily synthesized by the Mannich reaction of upper-rim unsubstituted resorcin[4
  • column anion exchange using DOWEX® 50W resin. Chiral resorcinarenes (R)-2 and (S)-2 were synthesized by the Mannich reaction of C-(3-hydroxypropyl)resorcin[4]arene with (R)- or (S)-2-phenylethylamine and formaldehyde in methanol in 38% yield for (R)-2 and 36% yield for (S)-2 yields according to modified
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Published 12 Aug 2019

Efficiency Effsyn of complex syntheses as multicomponent reactions, its algorithm and calculations based on concrete criteria

  • Heiner Eckert

Beilstein J. Org. Chem. 2019, 15, 1425–1433, doi:10.3762/bjoc.15.142

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  • synthesis steps yn (Equation 1). An extreme example for the impact of the overall yield is the tropinone synthesis by Willstätter (yoa = 0.75%) [7][8] compared to the Robinson–Schöpf synthesis (yoa = 90%) [9][10]) using a double Mannich reaction, a multicomponent reaction (MCR) [11][12][13]. The Mannich-3CR
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Published 27 Jun 2019

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

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  • [68] increased the diversity of MCRs that can be used to ligate peptides to steroids with the development of a novel multicomponent conjugation process based on the Petasis-3CR. The Petasis reaction [69] also known as the borono-Mannich reaction, is a MCR comprising the condensation of an aldehyde or
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Published 06 Jun 2019

A chemoenzymatic synthesis of ceramide trafficking inhibitor HPA-12

  • Seema V. Kanojia,
  • Sucheta Chatterjee,
  • Subrata Chattopadhyay and
  • Dibakar Goswami

Beilstein J. Org. Chem. 2019, 15, 490–496, doi:10.3762/bjoc.15.42

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  • researches involving CERT inhibition. For this, a number of groups have successfully accomplished the synthesis of HPA-12 [13][14][15][16][17][18][19][20][21][22][23][24][25]. The first synthesis of HPA-12 comprised [13] a three-component asymmetric Mannich reaction catalyzed by a chiral zirconium catalyst
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Published 18 Feb 2019

Microwave-assisted synthesis of N,N-bis(phosphinoylmethyl)amines and N,N,N-tris(phosphinoylmethyl)amines bearing different substituents on the phosphorus atoms

  • Erika Bálint,
  • Anna Tripolszky,
  • László Hegedűs and
  • György Keglevich

Beilstein J. Org. Chem. 2019, 15, 469–473, doi:10.3762/bjoc.15.40

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  • ][3][4]. In addition, a few Pt, Ru and Au complexes incorporating phosphine ligands show significant anticancer activity [5][6]. One of the most common synthetic routes to α-aminophosphine oxides is the Kabachnik–Fields (phospha-Mannich) reaction, where an amine, an oxo compound (aldehyde or ketone
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Published 15 Feb 2019

Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

  • Falco Fox,
  • Jörg M. Neudörfl and
  • Bernd Goldfuss

Beilstein J. Org. Chem. 2019, 15, 167–186, doi:10.3762/bjoc.15.17

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  • )–2.05(2) Å) than with chlorosilanol 8 (OH···2.16(0) Å). Due to its two hydroxy units, the silanediol 9 shows higher catalytic activity as hydrogen bond donor than chlorosilanol 8, e.g., C–C coupling N-acyl Mannich reaction of silyl ketene acetals 11 with N-acylisoquinolinium ions (up to 85% yield and 12
  • ion catalyses The N-acyl Mannich reaction of isochinolin (16), which is activated with 2,2,2-trichloroethoxycarbonyl chloride (17, TrocCl) to carbamate 10, and different silyl ketene acetals 11a–d yielding product 12 (Scheme 6) [45][47], is studied. Mattson et al. proposed a mechanism where the
  • % (Table 9, entry 7). For 11a, b and d and silanediol 9 as catalyst, an enantiomeric inversion is observed (Table 9, entries 5, 6 and 8). The substrate scope is broadened with 1-chloroisochroman (18) as alternative substrate (Table 10). The reaction mechanism is analogue to the N-acyl Mannich reaction
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Published 18 Jan 2019

A novel and practical asymmetric synthesis of eptazocine hydrobromide

  • Ruipeng Li,
  • Zhenren Liu,
  • Liang Chen,
  • Jing Pan,
  • Kuaile Lin and
  • Weicheng Zhou

Beilstein J. Org. Chem. 2018, 14, 2340–2347, doi:10.3762/bjoc.14.209

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  • Mannich reaction to construct the tricyclic framework of 6. The study started with the alkylation under catalysis of 3 in a two-phase system of chlorobenzene and 50% aqueous NaOH solution based on our previous report [14]. When the reaction was run at 0–5 °C, an excellent yield (70%) and enantiomeric
  • -methyl-7-methoxy-2-tetralone and a Mannich reaction to construct the tricyclic compound in eight linear steps. The optimization of reaction conditions were carried out to get a practical route delivering the product in excellent yield and purity (>99%). Experimental All solvents and reagents were from
  • replaced with HOAc/H2O (2:1) or Pd/C was selected as a catalyst, the reaction gave a similar result as with Raney-Ni as catalyst in NH3/CH3OH. It seems that compound 5 easily reacted with the carbonyl group to form the five-membered ring. Since the carbonyl group is necessary for the following Mannich
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Published 06 Sep 2018

Synthesis of chiral 3-substituted 3-amino-2-oxindoles through enantioselective catalytic nucleophilic additions to isatin imines

  • Hélène Pellissier

Beilstein J. Org. Chem. 2018, 14, 1349–1369, doi:10.3762/bjoc.14.114

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  • also proved to be highly efficient for a range of transformations. Review Enantioselective Mannich reactions Organocatalyzed reactions Originally, the Mannich reaction is a three-component process occurring between an aldehyde, an amine and a ketone, providing β-amino carbonyl compounds [23][24][25
  • 2015 by Enders et al. at a remarkably low catalyst loading (0.0225 mol %) to promote the enantioselective Mannich reaction of ethyl nitroacetate (2) with N-Boc-isatin imines 3 [35]. The process afforded, after a subsequent denitration, the corresponding chiral 3-amino-2-oxindoles 4 in moderate to high
  • products were converted into useful intermediates for the synthesis of pyrroloindoline alkaloids and related drugs, such as psychotrimine and (+)-folicanthine. Later in 2016, Trivedi et al. reported the synthesis of chiral 3-amino-2-oxindoles through the Mannich reaction of N-Boc-isatin imines 3 with 1,3
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Published 06 Jun 2018

Mannich base-connected syntheses mediated by ortho-quinone methides

  • Petra Barta,
  • Ferenc Fülöp and
  • István Szatmári

Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43

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  • adducts. Due to the important pharmacological activities of these reactive o-QM intermediates, special attention is paid to the biological activity of these compounds. Keywords: aminophenols; [4 + 2] cycloaddition; dienophile; Mannich reaction; ortho-quinone methide; Review Introduction The Mannich
  • secondary amine. Recently, one of its special variations called modified Mannich reaction, has gained ground, in which the C–H acid is replaced by electron-rich aromatic compounds such as 1- and 2-naphthols as active hydrogen sources [6]. At the beginning of the 20th century, Mario Betti reported the
  • -aminoalkyl-2-naphthol derivatives by a simple amide hydrolysis. The mechanism of the Mannich reaction is depicted in Scheme 1. First, the reaction between the aldehyde and 2-naphthol, induced by the catalyst, leads to the generation of o-QM intermediate 3 that reacts further with the amide component to form
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Published 06 Mar 2018

Regioselective decarboxylative addition of malonic acid and its mono(thio)esters to 4-trifluoromethylpyrimidin-2(1H)-ones

  • Sergii V. Melnykov,
  • Andrii S. Pataman,
  • Yurii V. Dmytriv,
  • Svitlana V. Shishkina,
  • Mykhailo V. Vovk and
  • Volodymyr A. Sukach

Beilstein J. Org. Chem. 2017, 13, 2617–2625, doi:10.3762/bjoc.13.259

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  • from the group of Ma described the development of a chiral thiourea-catalyzed enantioselective decarboxylative Mannich reaction of malonic acid monoesters with 4-trifluoromethylquinazolin-2(1H)-ones as heterocyclic trifluoromethylketimine substrates for the preparation of enantioenriched 3,4
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Published 07 Dec 2017

Mechanochemical synthesis of small organic molecules

  • Tapas Kumar Achar,
  • Anima Bose and
  • Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

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  • ]. Mechanochemical methods of the Mannich reaction, Paal–Knorr synthesis, Bigineli reaction, Hantzsch reaction, and syntheses of substituted pyran, thiophene, isoquinoline derivatives, etc. are also reported [104][107][112][113]. Isocyanide-based multi-component reactions are also well known [114][115]. Recently, in
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Published 11 Sep 2017

1-Imidoalkylphosphonium salts with modulated Cα–P+ bond strength: synthesis and application as new active α-imidoalkylating agents

  • Jakub Adamek,
  • Roman Mazurkiewicz,
  • Anna Węgrzyk and
  • Karol Erfurt

Beilstein J. Org. Chem. 2017, 13, 1446–1455, doi:10.3762/bjoc.13.142

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  • aldehydes or ketones (mainly formaldehyde) with ammonia or aliphatic amines and CH-acidic carbonyl compounds, known as the Mannich reaction, plays an important role in organic synthesis, despite some limitations of this reaction. α-Amidoalkylation reactions are considered an important extension of the
  • Mannich reaction [1][2][3]. They are crucial methods for the formation of >NC–C and >NC–Het bonds used, inter alia, for the generation of the β-aminocarbonyl substructure and for the construction of new carbo- or heterocyclic systems, especially in pharmaceutical chemistry and in the synthesis of natural
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Published 24 Jul 2017

A speedy route to sterically encumbered, benzene-fused derivatives of privileged, naturally occurring hexahydropyrrolo[1,2-b]isoquinoline

  • Olga Bakulina,
  • Alexander Ivanov,
  • Vitalii Suslonov,
  • Dmitry Dar’in and
  • Mikhail Krasavin

Beilstein J. Org. Chem. 2017, 13, 1413–1424, doi:10.3762/bjoc.13.138

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  • ) N-acylation of the imine component followed by intramolecular Mannich reaction or (b) Mannich-type addition of the HPA enolate to a protonated imine component followed by intramolecular aminolysis of the cyclic anhydride moiety in Mannich adduct 13 (Scheme 3) [1]. Investigation of the CCR leading to
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Published 18 Jul 2017

Exploring endoperoxides as a new entry for the synthesis of branched azasugars

  • Svenja Domeyer,
  • Mark Bjerregaard,
  • Henrik Johansson and
  • Daniel Sejer Pedersen

Beilstein J. Org. Chem. 2017, 13, 644–647, doi:10.3762/bjoc.13.63

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  • TEMPO, whereas oxidation of 6 using the Parikh–Doering method gave a good yield of aldehyde 10. Next, aldehydes 7, 9 and 10 were subjected to a Mannich reaction using the method by Erkkilä and Pihko to give the α,β-unsaturated aldehydes 11–13 in good yields [20]. The final step of the diene synthesis
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Published 03 Apr 2017

Synthesis of 1-indanones with a broad range of biological activity

  • Marika Turek,
  • Dorota Szczęsna,
  • Marek Koprowski and
  • Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

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  • 116 was isolated in 60% yield and further used in the synthesis of the natural product. Hexamethylenetetramine (HMTA) is a commonly used promoter of aryl alkyl ketones in the Mannich reaction which has been applied in the synthesis of α,β-unsaturated ketones 119 [64]. The HMTA/acetic anhydride
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Published 09 Mar 2017

Synthesis of structurally diverse 3,4-dihydropyrimidin-2(1H)-ones via sequential Biginelli and Passerini reactions

  • Andreas C. Boukis,
  • Baptiste Monney and
  • Michael A. R. Meier

Beilstein J. Org. Chem. 2017, 13, 54–62, doi:10.3762/bjoc.13.7

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  • dihydropyridine synthesis (1882), the Biginelli dihydropyrimidone synthesis (1891), the Mannich reaction (1912), the Passerini three-component reaction (1921) and the Ugi four-component reaction (1959) [9]. In this work, we used Biginelli and Passerini reactions to synthesize highly functionalized compounds
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Published 09 Jan 2017

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

  • Pavel Nagorny and
  • Zhankui Sun

Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283

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  • -methylpiperidinium iodide. Both L5 and L6 were found to promote the Mannich reaction between N-Troc-isoquinolinium chlorides and silyl enol ethers. Catalyst L6 with non-coordinating BArF− counterion was found to have a significantly higher activity than L5 with iodide counterion, probably, due to the competitive
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Published 23 Dec 2016

β-Amino functionalization of cinnamic Weinreb amides in ionic liquid

  • Yi-Ning Wang,
  • Guo-Xiang Sun and
  • Gang Qi

Beilstein J. Org. Chem. 2016, 12, 2372–2377, doi:10.3762/bjoc.12.231

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  • towards the preparation of β-amino carbonyl compounds is the Mannich reaction [8][9]. However, there are few reported methods specifically focused on this target, which include oxidation of γ-amino alcohols [10], hydrolysis of 1,3-oxazines [11], rearrangement of 2,3-aziridinio alcohols [12], etc. N
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Published 11 Nov 2016

Highly chemo-, enantio-, and diastereoselective [4 + 2] cycloaddition of 5H-thiazol-4-ones with N-itaconimides

  • Shuai Qiu,
  • Choon-Hong Tan and
  • Zhiyong Jiang

Beilstein J. Org. Chem. 2016, 12, 2293–2297, doi:10.3762/bjoc.12.222

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  • decreases the free energy of the second formal Mannich reaction, thus improving the reaction rate and chemoselectivity of the [4 + 2] cycloaddition. To extend the usefulness of this reaction, we demonstrate that the adduct can be efficiently reduced with borane. As shown in Scheme 2, 3a was readily reduced
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Published 01 Nov 2016

Chiral ammonium betaine-catalyzed asymmetric Mannich-type reaction of oxindoles

  • Masahiro Torii,
  • Kohsuke Kato,
  • Daisuke Uraguchi and
  • Takashi Ooi

Beilstein J. Org. Chem. 2016, 12, 2099–2103, doi:10.3762/bjoc.12.199

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  • quaternary and tertiary stereogenic carbon centers on biologically intriguing molecular frameworks with high fidelity. Keywords: ammonium betaine; asymmetric catalysis; Mannich reaction; organocatalysis; oxindole; Introduction Chiral indole alkaloids possessing C-3 quaternary indoline frameworks are an
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Published 28 Sep 2016

Rh-Catalyzed reductive Mannich-type reaction and its application towards the synthesis of (±)-ezetimibe

  • Motoyuki Isoda,
  • Kazuyuki Sato,
  • Yurika Kunugi,
  • Satsuki Tokonishi,
  • Atsushi Tarui,
  • Masaaki Omote,
  • Hideki Minami and
  • Akira Ando

Beilstein J. Org. Chem. 2016, 12, 1608–1615, doi:10.3762/bjoc.12.157

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  • Mannich-type reaction; rhodium–hydride; zinc enolate; Introduction The Mannich reaction is an important and classical C–C bond-forming reaction between an enolizable carbonyl compound and an imine to give the corresponding β-aminocarbonyl compound. For example, Shibasaki and his colleague reported the
  • asymmetric Mannich reaction using a Lewis acid catalyst [1]. (L)-Proline is known as an excellent promoter for the Mannich reaction [2][3][4][5][6], and besides this, the reaction of the silyl enol ether derivatives with imines was used as an effective method [7][8][9]. In this situation, a wide variety of
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Published 27 Jul 2016

The aminoindanol core as a key scaffold in bifunctional organocatalysts

  • Isaac G. Sonsona,
  • Eugenia Marqués-López and
  • Raquel P. Herrera

Beilstein J. Org. Chem. 2016, 12, 505–523, doi:10.3762/bjoc.12.50

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  • have exhibited efficient catalytic activity in the asymmetric Mannich reaction. In fact, the use of simple trans-(1R,2R)-aminoindanol (1c) as an efficient organocatalyst in the enantioselective synthesis of natural products as the TMC-954 core [12][13], has been recently reported. These examples show
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Published 14 Mar 2016

(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

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  • transformation is initiated by a Michael addition of 158 to alkylidene azlactone 159, followed by a Mannich reaction and finally transesterification. The same year, Yuan and co-workers reported the double Michael reaction between 160 and alkylidene azlactone 161 to produce the spiro-fused cyclohexanone/5
  • catalyst 223 activates aldehyde 213, through the formation of the corresponding enamine. Then, the enamine reacts with nitro-alkene 82, which is activated by hydrogen bonding due to catalyst 228. Thus, the formed intermediate can now participate to a nitro-Mannich reaction, affording a N-protected
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Published 10 Mar 2016
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