Search results

Search for "α,β-unsaturated carbonyl" in Full Text gives 65 result(s) in Beilstein Journal of Organic Chemistry.

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

  • Thilo Focken and
  • Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

Graphical Abstract
PDF
Album
Review
Published 13 Aug 2014

Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilyl)methyl)aniline with cyclic α,β-unsaturated carbonyl compounds

  • Dominik Lenhart and
  • Thorsten Bach

Beilstein J. Org. Chem. 2014, 10, 890–896, doi:10.3762/bjoc.10.86

Graphical Abstract
  • -induced, iridium-catalyzed addition reactions to cyclic α,β-unsaturated carbonyl compounds. Typical reaction conditions included the use of one equivalent of the reaction substrate, 1.5 equivalents of the aniline and 2.5 mol % (in MeOH) or 1.0 mol % (in CH2Cl2) [Ir(ppy)2(dtbbpy)]BF4 as the catalyst. Two
  • reactions to other cyclic α,β-unsaturated carbonyl compounds. In particular, we were interested to see whether cyclization reactions as for product 4 would be observed when using α,β-unsaturated lactones and lactams in combination with a silylated amine and an iridium catalyst. In this article, we provide
  • 7 operates [54][55][56][57][58]. Oxidation of the aniline and loss of the trimethylsilyl group leads to an α-aminomethyl radical, which adds to the cyclic α,β-unsaturated carbonyl compound (Scheme 8). The intermediate radical A can undergo immediate reduction presumably by concomitant oxidation of
PDF
Album
Supp Info
Full Research Paper
Published 17 Apr 2014

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

  • Marcus Baumann and
  • Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

Graphical Abstract
  • derivatives are treated with α,β-unsaturated carbonyl compounds in the presence of ammonia to initially form dihydropyridines 1.38, which can ultimately be converted into the corresponding aromatic pyridine upon oxidation with a variety of oxidants such as MnO2, HNO2, HNO3 or cerium ammonium nitrate (CAN
PDF
Album
Review
Published 30 Oct 2013

Elucidation of the regio- and chemoselectivity of enzymatic allylic oxidations with Pleurotus sapidus – conversion of selected spirocyclic terpenoids and computational analysis

  • Verena Weidmann,
  • Mathias Schaffrath,
  • Holger Zorn,
  • Julia Rehbein and
  • Wolfgang Maison

Beilstein J. Org. Chem. 2013, 9, 2233–2241, doi:10.3762/bjoc.9.262

Graphical Abstract
  • ] or α,β-unsaturated carbonyl compounds are attractive synthetic targets of high economic and scientific interest [11][12][13][14][15][16][17]. Allylic oxidations of olefins to enones have classically been performed with strong oxidants such as chromium or other metal-based reagents [18][19]. In
PDF
Album
Supp Info
Full Research Paper
Published 29 Oct 2013

AgOTf-catalyzed one-pot reactions of 2-alkynylbenzaldoximes with α,β-unsaturated carbonyl compounds

  • Qiuping Ding,
  • Dan Wang,
  • Puying Luo,
  • Meiling Liu,
  • Shouzhi Pu and
  • Liyun Zhou

Beilstein J. Org. Chem. 2013, 9, 1949–1956, doi:10.3762/bjoc.9.231

Graphical Abstract
  • various α,β-unsaturated carbonyl compounds under mild conditions are described, which provides a facile and efficient pathway for the synthesis of 1-alkylated isoquinoline derivatives. The method tolerates a wide range of substrates and allows for the preparation of the products of interest in moderate to
  • excellent yields. Keywords: 2-alkynylbenzaldoxime; cyclization; 2-(isoquinolin-1-yl)ethanol; rearrangement; α,β-unsaturated carbonyl compound; Introduction One-pot combinations of multi-catalysis and multi-component cascade reactions [1][2][3][4][5][6], in which several bond-forming steps take place in a
  • progress in this aspect. Wu and co-workers described an efficient three-component reaction of a 2-alkynylbenzaldoxime and an α,β-unsaturated carbonyl compound with bromine or iodine monochloride under mild conditions, which generates the 1-alkylated isoquinolines in good to excellent yields [36]. Wu and co
PDF
Album
Supp Info
Full Research Paper
Published 27 Sep 2013

Raman spectroscopy as a tool for monitoring mesoscale continuous-flow organic synthesis: Equipment interface and assessment in four medicinally-relevant reactions

  • Trevor A. Hamlin and
  • Nicholas E. Leadbeater

Beilstein J. Org. Chem. 2013, 9, 1843–1852, doi:10.3762/bjoc.9.215

Graphical Abstract
  • is assessed by studying four reactions, all involving formation of products bearing α,β-unsaturated carbonyl moieties; synthesis of 3-acetylcoumarin, Knoevenagel and Claisen–Schmidt condensations, and a Biginelli reaction. In each case it is possible to monitor the reactions and also in one case, by
  • means of a calibration curve, determine product conversion from Raman spectral data as corroborated by data obtained using NMR spectroscopy. Keywords: flow processing; Raman spectroscopy; reaction monitoring; α,β-unsaturated carbonyl; Introduction Continuous-flow processing is used in the chemical
PDF
Album
Supp Info
Full Research Paper
Published 11 Sep 2013

Dipolar addition to cyclic vinyl sulfones leading to dual conformation tricycles

  • Steven S. Y. Wong,
  • Michael G. Brant,
  • Christopher Barr,
  • Allen G. Oliver and
  • Jeremy E. Wulff

Beilstein J. Org. Chem. 2013, 9, 1419–1425, doi:10.3762/bjoc.9.159

Graphical Abstract
  • expedient regio- and stereospecific synthesis of five-membered ring N-, O- or S-containing heterocycles [4][5]. Various 1,3-dipoles can be used, including nitrones [6], azomethine ylides [7], diazoalkanes [8][9] and many others [10][11][12]. α,β-Unsaturated carbonyl compounds are often found to be good
PDF
Album
Supp Info
Full Research Paper
Published 15 Jul 2013

New simple synthesis of ring-fused 4-alkyl-4H-3,1-benzothiazine-2-thiones: Direct formation from carbon disulfide and (E)-3-(2-aminoaryl)acrylates or (E)-3-(2-aminoaryl)acrylonitriles

  • Qiuping Ding,
  • Yuqing Lin,
  • Guangni Ding,
  • Fumin Liao,
  • Xiaoyan Sang and
  • Yi-Yuan Peng

Beilstein J. Org. Chem. 2013, 9, 460–466, doi:10.3762/bjoc.9.49

Graphical Abstract
  • or isothiocyanates bearing one o-substituted α,β-unsaturated carbonyl fragment promoted by the CS2/TBAF system [17]. However, both the low yields (30–60%) of the products and the substrate limitations outweigh their advantages. As part of a continuing effort in our laboratory toward the development
PDF
Album
Supp Info
Full Research Paper
Published 01 Mar 2013

Reactions of salicylaldehyde and enolates or their equivalents: versatile synthetic routes to chromane derivatives

  • Ishmael B. Masesane and
  • Zelalem Yibralign Desta

Beilstein J. Org. Chem. 2012, 8, 2166–2175, doi:10.3762/bjoc.8.244

Graphical Abstract
  • (5), followed by an intramolecular aldol reaction and final dehydration to give the desired chromene derivative. Related work involving asymmetric reaction of salicylaldehyde derivatives and α,β-unsaturated carbonyl compounds in the synthesis of 2-phenylchromenes was reported by Li and co-workers
PDF
Album
Review
Published 12 Dec 2012

Synthesis and ring openings of cinnamate-derived N-unfunctionalised aziridines

  • Alan Armstrong and
  • Alexandra Ferguson

Beilstein J. Org. Chem. 2012, 8, 1747–1752, doi:10.3762/bjoc.8.199

Graphical Abstract
  • carbonyl compounds. Our method produces trans-NH-aziridines from α,β-unsaturated carbonyl compounds in good to excellent yield with high diastereoselectivity (Figure 1) [21]. An N–N ylide (aminimine) is the presumed active intermediate, formed from the reaction of a tertiary amine promoter and an aminating
  • dihydroxylation, conversion to a cyclic sulfate, ring opening with azide, and finally ring closure to afford the NH-aziridine [18]. We recently reported [21][22] a nucleophilic aziridination methodology [23][24][25][26][27][28][29][30] that allows access to NH-aziridines in a single step from α,β-unsaturated
PDF
Album
Supp Info
Full Research Paper
Published 12 Oct 2012

Construction of cyclic enones via gold-catalyzed oxygen transfer reactions

  • Leping Liu,
  • Bo Xu and
  • Gerald B. Hammond

Beilstein J. Org. Chem. 2011, 7, 606–614, doi:10.3762/bjoc.7.71

Graphical Abstract
  • - or Lewis acid-catalyzed oxygen transfer from carbonyl to carbon–carbon triple bond, the so-called alkyne–carbonyl metathesis, has attracted much attention because this atom economical transformation generates α,β-unsaturated carbonyl derivatives which are of great interest in synthetic organic
  • ; gold-catalyzed; oxonium; oxygen transfer; Review α,β-Unsaturated carbonyl derivatives are not only important building blocks in synthetic organic chemistry, but are also a significant motif in natural products and biologically active compounds [1][2][3][4][5][6][7][8]. The construction of the
PDF
Album
Review
Published 13 May 2011

Michael-type addition of azoles of broad-scale acidity to methyl acrylate

  • Sławomir Boncel,
  • Kinga Saletra,
  • Barbara Hefczyc and
  • Krzysztof Z. Walczak

Beilstein J. Org. Chem. 2011, 7, 173–178, doi:10.3762/bjoc.7.24

Graphical Abstract
  • of various azoles to α,β-unsaturated carbonyl and nitro derivatives has been frequently exploited in the synthesis of precursors of biologically active compounds [3][7][8][9][10][11][12][13][14][15]. This reaction, although structurally restricted to α,β-unsaturated carbonyl compounds and their
PDF
Album
Supp Info
Letter
Published 08 Feb 2011

Aroylketene dithioacetal chemistry: facile synthesis of 4-aroyl- 3-methylsulfanyl- 2-tosylpyrroles from aroylketene dithioacetals and TosMIC

  • H. Surya Prakash Rao and
  • S. Sivakumar

Beilstein J. Org. Chem. 2007, 3, No. 31, doi:10.1186/1860-5397-3-31

Graphical Abstract
  • to general α,β-unsaturated carbonyl compounds. Background The α-aroylketene dithioacetals (AKDTAs) 1 are useful three-carbon synthones extensively employed for the synthesis of a wide variety of heterocyclic compounds and also in several aromatic ring annulation reactions. [1][2] The AKDTAs are α,β
  • -unsaturated carbonyl compounds with two electron-donating alkylsulafanyl groups on one end and an electron-withdrawing aroyl group at the other end of the double bond, i.e., they are "push-pull" alkenes. Depending on the nucleophile and the reaction conditions either 1,2- or 1,4-necleophilc additions on 1 are
PDF
Album
Supp Info
Full Research Paper
Published 28 Sep 2007

Variations in product in reactions of naphthoquinone with primary amines

  • Marjit W. Singh,
  • Anirban Karmakar,
  • Nilotpal Barooah and
  • Jubaraj B. Baruah

Beilstein J. Org. Chem. 2007, 3, No. 10, doi:10.1186/1860-5397-3-10

Graphical Abstract
  • based on the established fact that the presence of a carbonyl group favors γ-attack on a α-β unsaturated carbonyl over an imine; we would like to put forward the first path. But it is still not clear about the aromatization process, whether it is a unimolecular, or a bimolecular process. Work is in
PDF
Album
Supp Info
Preliminary Communication
Published 01 Mar 2007

One-pot synthesis of novel 1H-pyrimido[4,5-c][1,2]diazepines and pyrazolo[3,4-d]pyrimidines

  • Dipak Prajapati,
  • Partha P. Baruah,
  • Baikuntha J. Gogoi and
  • Jagir S. Sandhu

Beilstein J. Org. Chem. 2006, 2, No. 5, doi:10.1186/1860-5397-2-5

Graphical Abstract
  • discussions The synthesis of pyrimido [4,5-c][1,2]diazepine-6,8-dione 3a was accomplished by reacting equimolar quantities of 1,3-dimethyl-6-hydrazino uracil 1 and α,β-unsaturated carbonyl compound 2a in ethanol under reflux for 3 h (monitored by TLC). The suspension of 6-hydrazino uracil 1 first disappeared
  • through involvement of an azine (obtained from oxidation of hydrazine group). Similarly other α,β-unsaturated carbonyl compounds 2b-e were reacted and the corresponding pyrimido[1,2]diazepines 3b-e were obtained in 78–90% yields and were characterized fully by spectroscopic and elemental analyses. The IR
PDF
Album
Supp Info
Full Research Paper
Published 23 Mar 2006
Other Beilstein-Institut Open Science Activities