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

Diastereoselective Ugi reaction of chiral 1,3-aminoalcohols derived from an organocatalytic Mannich reaction

  • Samantha Caputo,
  • Andrea Basso,
  • Lisa Moni,
  • Renata Riva,
  • Valeria Rocca and
  • Luca Banfi

Beilstein J. Org. Chem. 2016, 12, 139–143, doi:10.3762/bjoc.12.15

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  • Samantha Caputo Andrea Basso Lisa Moni Renata Riva Valeria Rocca Luca Banfi Department of Chemistry and Industrial Chemistry, University of Genova, I-16146 Genova, Italy 10.3762/bjoc.12.15 Abstract Enantiomerically pure β-aminoalcohols, produced through an organocatalytic Mannich reaction, were
  • 2 that were immediately submitted to List's organocatalytic Mannich reaction [29][30]. The resulting aldehydes 3 were not isolated (also in view of their known stereochemical lability) but directly reduced to alcohols 4 [32][33]. Purification was carried out through chromatography and, in some cases
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Published 26 Jan 2016

Investigation of the role of stereoelectronic effects in the conformation of piperidones by NMR spectroscopy and X-ray diffraction

  • Cesar Garcias-Morales,
  • David Ortegón-Reyna and
  • Armando Ariza-Castolo

Beilstein J. Org. Chem. 2015, 11, 1973–1984, doi:10.3762/bjoc.11.213

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  • .11.213 Abstract This paper reports the synthesis of a series of piperidones 1–8 by the Mannich reaction and analysis of their structures and conformations in solution by NMR and mass spectrometry. The six-membered rings in 2,4,6,8-tetraphenyl-3,7-diazabicyclo[3.3.1]nonan-9-ones, compounds 1 and 2, adopt
  • synthesized by the Mannich reaction [46][47][48][49]. As shown in Scheme 1; 1 and 2 were synthesized using ammonium acetate, benzaldehyde, and acetone or 2-butanone (4:4:1), respectively [50][51][52]. When we probed this reaction with 3-pentanone, the product was 3,5-dimethyl-2,6-diphenylpiperidin-4-one
  • in the structures obtained by XRD. Proposed reaction mechanism for the synthesis of piperidones by the Mannich reaction. The substituents are shown in Figure 4. For 6, R1 = R2 = H, for 7, R1 = H, R2 = CH3, for 8, R1 = R2 = CH3. Representation of the nN→σ*C–H(7)eq interaction. The interaction energy
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Published 22 Oct 2015

Selected synthetic strategies to cyclophanes

  • Sambasivarao Kotha,
  • Mukesh E. Shirbhate and
  • Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

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  • compounds which are discussed in detail in this review. Review Synthetic routes to cyclophanes Addition reactions Mannich reaction: In 2001, Erker and co-workers [84] have reported the synthesis of amino-substituted [3]ferrocenophane through an intramolecular Mannich reaction starting with the ferrocene
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Published 29 Jul 2015

Syntheses of 15N-labeled pre-queuosine nucleobase derivatives

  • Jasmin Levic and
  • Ronald Micura

Beilstein J. Org. Chem. 2014, 10, 1914–1918, doi:10.3762/bjoc.10.199

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  • Mannich reaction using dibenzylamine–formaldehyde and 2-acylaminopyrrolo[2,3-d]pyrimidin-4(3H)-one, which resulted in the selective introduction of the dibenzylaminomethyl group [10]. The following amine exchange reaction of the dibenzylamine function in the Mannich base with ammonia resulted in the preQ1
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Published 18 Aug 2014

Multicomponent reactions in nucleoside chemistry

  • Mariola Koszytkowska-Stawińska and
  • Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

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  • nucleosides as (i) reaction components, or (ii) products obtained from non-nucleoside substrates. The cited references are grouped according to the usually recognized types of the MCRs [46]. Review 1. The Mannich reaction The classical Mannich reaction yields β-aminoaldehydes or β-aminoketones and involves
  • : an aldehyde, a primary (or a secondary) amine, and an enolizable aldehyde (or ketone) (Scheme 1a) [47][48]. The use of a hydrogen active component other than an enolizable aldehyde or ketone leads to a variety of structurally diverse products (Scheme 1b). The Mannich reaction products (commonly named
  • as Mannich bases) can serve as starting materials in the syntheses of a variety of compounds. The employment of a nucleoside as the hydrogen active component has been one of the most common variants of the Mannich reaction. Treatment of uracil (or 2-thiouracil) nucleosides 1 with aq formaldehyde and
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Published 29 Jul 2014

Silver and gold-catalyzed multicomponent reactions

  • Giorgio Abbiati and
  • Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

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  • oxazoles 68 (Scheme 34). Another cluster of silver-mediated Mannich-type reactions involves the enantioselective addition of siloxyfurans 70 to imines 69 (vinylogous Mannich reaction, VM) affording chiral butenolide derivatives 71 (Scheme 35). The reaction proceeds in the presence of amino acid-based
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Published 26 Feb 2014

Boron-substituted 1,3-dienes and heterodienes as key elements in multicomponent processes

  • Ludovic Eberlin,
  • Fabien Tripoteau,
  • François Carreaux,
  • Andrew Whiting and
  • Bertrand Carboni

Beilstein J. Org. Chem. 2014, 10, 237–250, doi:10.3762/bjoc.10.19

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  • and (E)-styrylboronic acid [12]. This was the first report of this type of transformation, which is now referred as the Petasis borono–Mannich reaction, and was later extended to a wide variety of other aldehydes, such as glyoxylic acid (for example), boronic acids, esters or trifluoroborates and
  • sequence. A two-step reaction sequence for the synthesis of tetrahydronaphthalenes 12. Tandem sequence based on the Petasis borono–Mannich reaction as first key step. One-pot tandem dimerization/allylboration reaction of 1,3-diene-2-boronate. Tandem Diels–Alder/cross-coupling reactions of trifluoroborates
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Published 22 Jan 2014

Total synthesis of (−)-epimyrtine by a gold-catalyzed hydroamination approach

  • Thi Thanh Huyen Trinh,
  • Khanh Hung Nguyen,
  • Patricia de Aguiar Amaral and
  • Nicolas Gouault

Beilstein J. Org. Chem. 2013, 9, 2042–2047, doi:10.3762/bjoc.9.242

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  • of (−)-epimyrtine have been described to date including the intramolecular allylsilane N-acyliminium ion cyclization [6], the organocatalytic aza-Michael reaction [7], the intramolecular Mannich reaction [8], and the iminium ion cascade reaction [9][10]. More efficient, convenient and highly
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Published 09 Oct 2013

The chemistry of amine radical cations produced by visible light photoredox catalysis

  • Jie Hu,
  • Jiang Wang,
  • Theresa H. Nguyen and
  • Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

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  • nucleophile 28 in situ, which is then added to photogenically formed iminium ion 27 to yield the Mannich product 23. The Mannich reaction was sluggish without the Lewis base, and a side reaction, formation of the oxidized isoquinoline, became significant. The choice of Lewis base was found to be also crucial
  • work much better using the former catalyst. Other types of pronucleophiles such as malonates are also effective in the Mannich reaction. The Rueping group extended the concept of dual catalysis by merging visible light photocatalysis with a metal-catalyzed process (Scheme 10) [77]. To make this
  • reaction. Merging Au-based photoredox catalysis and Lewis base catalysis for the Mannich reaction. Merging Ru-based photoredox catalysis and Cu-catalyzed alkynylation reaction. Merging Ru-based photoredox catalysis and NHC catalysis. 1,3-Dipolar cycloaddition of photogenically formed azomethine ylides
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Published 01 Oct 2013

Asymmetric allylic alkylation of Morita–Baylis–Hillman carbonates with α-fluoro-β-keto esters

  • Lin Yan,
  • Zhiqiang Han,
  • Bo Zhu,
  • Caiyun Yang,
  • Choon-Hong Tan and
  • Zhiyong Jiang

Beilstein J. Org. Chem. 2013, 9, 1853–1857, doi:10.3762/bjoc.9.216

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  • conjugate addition and Mannich reaction of α-fluoro-β-ketoesters with excellent results [38][39][40]. Herein, we wish to report the first allylic alkylation of MBH carbonates with α-fluoro-β-ketoesters in excellent enantioselectivities and moderate diastereoselectivities, furnishing enantiopure fluorinated
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Published 11 Sep 2013

Synthesis of the reported structure of piperazirum using a nitro-Mannich reaction as the key stereochemical determining step

  • James C. Anderson,
  • Andreas S. Kalogirou,
  • Michael J. Porter and
  • Graham J. Tizzard

Beilstein J. Org. Chem. 2013, 9, 1737–1744, doi:10.3762/bjoc.9.200

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  • Abstract Piperazirum, isolated from Arum palaestinum Boiss, was originally assigned as r-3,c-5-diisobutyl-c-6-isopropylpiperazin-2-one. The reported structure was synthesised diastereoselectively using a key nitro-Mannich reaction to set up the C5/C6 relative stereochemistry. The structure was
  • ; Introduction The nitro-Mannich reaction (or aza-Henry reaction) has been developed to a standard where the product β-nitroamines 1 are now privileged building blocks. In part this is due to the complementary synthetic flexibility available from the two different nitrogen atom oxidation states (Scheme 1) [1
  • ][37][38][39]. A large part of our own work in developing the nitro-Mannich reaction was to demonstrate the preparation of stereodefined 1,2-diamines [40][41][42][43][44][45]. As part of a programme aimed at using these 1,2-diamines as building blocks in target synthesis we focused on the synthesis of
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Published 23 Aug 2013

An organocatalytic route to 2-heteroarylmethylene decorated N-arylpyrroles

  • Alexandre Jean,
  • Jérôme Blanchet,
  • Jacques Rouden,
  • Jacques Maddaluno and
  • Michaël De Paolis

Beilstein J. Org. Chem. 2013, 9, 1480–1486, doi:10.3762/bjoc.9.168

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  • limitation being the formation of the corresponding imines. Similarly, imine 2d prepared from para-bromoaniline was found to be unstable and only degradation was observed during the Mannich reaction. When imine 2e, derived from the para-iodoaniline, was engaged in the process, the hydroamination step turned
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Published 24 Jul 2013

Study on the total synthesis of velbanamine: Chemoselective dioxygenation of alkenes with PIFA via a stop-and-flow strategy

  • Huili Liu,
  • Kuan Zheng,
  • Xiang Lu,
  • Xiaoxia Wang and
  • Ran Hong

Beilstein J. Org. Chem. 2013, 9, 983–990, doi:10.3762/bjoc.9.113

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  • efforts on method development toward the efficient construction of velbanamine-type indole alkaloids. As shown in Scheme 2, an intramolecular Heck reaction (via 9-exo manner) would finalize the 9-membered ring, which was biogenetically derived from a retro-Mannich reaction from catharanthine (Scheme 1
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Published 23 May 2013

Some aspects of radical chemistry in the assembly of complex molecular architectures

  • Béatrice Quiclet-Sire and
  • Samir Z. Zard

Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61

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  • afford a benzothiepinone (Scheme 13) [32]. In the particular case of 65a, oxidation to the corresponding sulfone 66 followed by a Mannich reaction with various aldehydes leads to a plethora of complex polycyclic structures 67a–e, which may be viewed as analogues of eptazocine 68 [32]. Oxidation to the
  • sulfone is necessary: when the Mannich reaction of benzothiepinone 65b with formaldehyde was attempted, the reaction resulted in the formation of novel tricyclic sulfonium 69 in modest yield [32]. It is also possible to profit from the ability of xanthates to mediate additions to olefins containing
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Published 18 Mar 2013

Efficient synthesis of β’-amino-α,β-unsaturated ketones

  • Isabelle Abrunhosa-Thomas,
  • Aurélie Plas,
  • Nishanth Kandepedu,
  • Pierre Chalard and
  • Yves Troin

Beilstein J. Org. Chem. 2013, 9, 486–495, doi:10.3762/bjoc.9.52

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  • nitrogen-containing molecules often found in medicinal chemistry [6][7][8][9][10]. Thus, the development of efficient and stereoselective reactions for a useful approach to chiral β-amino ketones is still of importance. One of the most powerful approaches is the Mannich reaction, which can be conducted
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Published 06 Mar 2013

The chemistry of bisallenes

  • Henning Hopf and
  • Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

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Published 15 Nov 2012

Asymmetric organocatalytic decarboxylative Mannich reaction using β-keto acids: A new protocol for the synthesis of chiral β-amino ketones

  • Chunhui Jiang,
  • Fangrui Zhong and
  • Yixin Lu

Beilstein J. Org. Chem. 2012, 8, 1279–1283, doi:10.3762/bjoc.8.144

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  • Chunhui Jiang Fangrui Zhong Yixin Lu Department of Chemistry & Medicinal Chemistry Program, Life Sciences Institute, National University of Singapore, 3 Science Drive 3, Republic of Singapore, 117543 10.3762/bjoc.8.144 Abstract The first decarboxylative Mannich reaction employing β-keto acids
  • , catalyzed by cinchonine-derived bifunctional thiourea catalyst has been described. The desired β-amino ketones were obtained in excellent yields and with moderate to good enantioselectivities. Keywords: decarboxylative addition; β-keto acid; Mannich reaction; organocatalysis; Introduction Chiral β-amino
  • few decades [7]. Among them, the Mukaiyama–Mannich reaction performed with silyl enol ethers and sulfonyl aldimines, catalyzed by a chiral Lewis acid complex, is one of the most important synthetic methods [8][9][10][11][12][13]. Apparently, direct use of inactivated ketones as a donor would be of
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Published 13 Aug 2012

Stereoselective, nitro-Mannich/lactamisation cascades for the direct synthesis of heavily decorated 5-nitropiperidin-2-ones and related heterocycles

  • Pavol Jakubec,
  • Dane M. Cockfield,
  • Madeleine Helliwell,
  • James Raftery and
  • Darren J. Dixon

Beilstein J. Org. Chem. 2012, 8, 567–578, doi:10.3762/bjoc.8.64

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  • -99,994 [68][69], inhibitors of farnesyltransferase [70][71], selective dipeptidyl peptidase IV inhibitors [72][73], and functionalised bispidines [74]. Very recently, a related cascade inspired by the original work of Jain incorporating C–C bond formation was accomplished through a nitro-Mannich reaction
  • stereochemical outcome of the cascade. - The second is that the nitro-Mannich reaction [78][79][80] is fast and reversible (but not necessarily stereoselective), and only one of the diastereomeric nitro-Mannich products preferentially cyclises in the irreversible lactamisation step to the (likely) most
  • ’). A further scrutiny of each hypothesis was, unfortunately, hampered by our failure to isolate or identify in situ the direct nitro-Mannich products from the reaction mixtures or to prepare them separately using standard procedures for a nitro-Mannich reaction with imines [109]. The first hypothesis
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Published 16 Apr 2012

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

  • Marcus Baumann,
  • Ian R. Baxendale,
  • Steven V. Ley and
  • Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

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Published 18 Apr 2011
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  • alkene functionalization such as aminohydroxylation [3] and dihydroxylation [4] reactions, or by methods that forge the carbon–carbon bond such as the glycolate Mannich reaction [5]. Recently, we developed a Brønsted acid-promoted azide–olefin reaction as an alternative to metal catalyzed
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Published 20 Dec 2010

Total synthesis of (±)-coerulescine and (±)-horsfiline

  • Mukund G. Kulkarni,
  • Attrimuni P. Dhondge,
  • Sanjay W. Chavhan,
  • Ajit S. Borhade,
  • Yunnus B. Shaikh,
  • Deekshaputra R. Birhade,
  • Mayur P. Desai and
  • Nagorao R. Dhatrak

Beilstein J. Org. Chem. 2010, 6, 876–879, doi:10.3762/bjoc.6.103

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  • include the following oxidative rearrangements: lead tetraacetate [3], sodium tungstate [11], tert-butyl hypochlorite [12] and N-bromosuccinimide [13]. Other approaches involve the Mannich reaction [14], ring expansion reactions [15][16], 1,3-dipolar [3 + 2] cycloadditions [17][18][19], intramolecular
  • [31], dimethyldioxirane (DMDO) mediated oxidation [32], and by tandem intramolecular photocycloaddition–retro-Mannich reaction [33]. The Wittig olefination–Claisen rearrangement protocol [35] provides a ready access to 4-pentenals, which have served as versatile intermediates for the synthesis of a
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Published 27 Sep 2010

Asymmetric reactions in continuous flow

  • Xiao Yin Mak,
  • Paola Laurino and
  • Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

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  • as donor, and subsequently to a Mannich reaction with α-iminoglyoxylate. Supported and heterogeneous catalysis Chiral catalysts and ligands are often expensive and the complete separation of these components from reaction products can frequently be quite challenging. Degradation products and leaching
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Published 29 Apr 2009
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