Results 101 to 110 of about 55,156 (263)

A New and Efficient Method for the Synthesis of 3,4-Disubstituted Pyrrolidine-2,5-diones

open access: yesMolecules, 2012
A newly found reaction for the synthesis of 3,4-disubstituted 1-hydroxy-pyrrolidine-2,5-diones from 3-substituted coumarins and nitromethane has been elaborated. The reaction involved a simple and convenient experimental procedure.
Rositca D. Nikolova   +2 more
doaj   +1 more source

Synthesis and use of a stable aminal derived from TsDPEN in asymmetric organocatalysis [PDF]

open access: yes, 2010
A stable aminal formed stereoselectively from (R,R)-N-tosyl-1,2-diphenyl-1,2-ethylenediamine (TsDPEN) is capable of asymmetric organocatalysis of Diels-Alder and alpha-amination reactions of ...
Clarkson, Guy J.   +3 more
core   +1 more source

Investigation of the In Vitro and In Vivo Metabolism and μ‐Opioid Receptor Affinity of the Nitazene N‐Pyrrolidino Fluetonitazene

open access: yesDrug Testing and Analysis, EarlyView.
Eight metabolites for N‐pyrrolidino fluetonitazene were identified in vitro, three of which (M2, M6 and M8) were present in an authentic urine sample. M2 was the most abundant in vivo metabolite and is a common marker metabolite of nitazepyne‐type substances.
Severin Zemp   +6 more
wiley   +1 more source

Crystal structure of ethyl (2S,2′R)-1′-benzyl-3-oxo-3H-dispiro[1-benzothiophene-2,3′-pyrrolidine-2′,11′′-indeno[1,2-b]quinoxaline]-4′-carboxylate

open access: yesActa Crystallographica Section E: Crystallographic Communications, 2015
In the title compound, C35H27N3O3S, the spiro-linked five-membered rings both adopt twisted conformations. The pyrrolidine ring makes dihedral angles of 80.5 (1) and 77.4 (9)° with the benzothiophene ring system and the quinoxaline ring system ...
J. Govindaraj   +4 more
doaj   +1 more source

Silver and platinum-catalysed addition of O–H and N–H bonds to allenes [PDF]

open access: yes, 2014
Transition-metal catalysed nucleophile addition to allenes is a very powerful tool for the synthesis of functionalised molecules containing heteroatoms, heterocycles in the intramolecular version, or allyl derivatives in the intermolecular version.
Munoz-Herranz, Maria
core   +1 more source

On the Planarity of Heterocyclic Bay‐Substituted Perylenediimides: Insight into the Fluorescent Photoinduced Electron Transfer Sensing Framework

open access: yesEuropean Journal of Organic Chemistry, EarlyView.
Near‐infrared fluorescent pH indicators based on perylenediimide were constructed in a modular receptor–spacer–fluorophore–spacer–receptor format with heterocyclic amino moieties at the bay positions. Counterintuitively, the dibrominated intermediate with two heavy atoms is more emissive than the heterocyclic compounds.
Luke Camenzuli   +4 more
wiley   +1 more source

The crystal structures of 6′-(4-chlorophenyl)- and 6′-(4-methoxyphenyl)-6a′-nitro-6a′,6b′,7′,9′,10′,12a′-hexahydro-2H,6′H,8′H-spiro[acenaphthylene-1,12′-chromeno[3,4-a]indolizin]-2-one

open access: yesActa Crystallographica Section E: Crystallographic Communications, 2019
In the title compounds, C32H25ClN2O4 (I) and C33H28N2O5 (II), the six-membered pyran and piperidine rings adopt envelope and chair conformations, respectively. The five-membered pyrrolidine rings adopt twist conformations. Compound (II) crystallizes with
S. Syed Abuthahir   +4 more
doaj   +1 more source

Sequencing around 5-hydroxyconiferyl alcohol-derived units in caffeic acid O-methyltransferase-deficient poplar lignins [PDF]

open access: yes, 2010
Caffeic acid O-methyltransferase (COMT) is a bifunctional enzyme that methylates the 5- and 3-hydroxyl positions on the aromatic ring of monolignol precursors, with a preference for 5-hydroxyconiferaldehyde, on the way to producing sinapyl alcohol ...
Adler   +35 more
core   +6 more sources

1,1‐Disubstituted Vinylbromides: Versatile Building Blocks for the Synthesis of Nitrogen‐Containing Heterocycles

open access: yesEuropean Journal of Organic Chemistry, EarlyView.
1,1‐Disubstituted vinylbromides are key intermediates for constructing nitrogen‐containing heterocycles. This review provides an overview of the synthetic applications of 1,1‐disubstituted vinylbromides and summarizes recent developments in reaction methodologies, mechanistic insights, and the structural diversity of N‐heterocyclic compounds accessible
Anne Westermeyer   +6 more
wiley   +1 more source

Crystal structure of ethyl 2′′,3-dioxo-7′,7a'-dihydro-1′H,3H,3′H-dispiro[benzo[b]thiophene-2,6′-pyrrolo[1,2-c]thiazole-5′,3′′-indoline]-7′-carboxylate

open access: yesActa Crystallographica Section E: Crystallographic Communications, 2015
In the title compound, C23H20N2O4S2, the central pyrrolidine ring adopts an envelope conformation with the spiro C atom, shared with the benzothiophene ring system, as the flap.
M. P. Savithri   +4 more
doaj   +1 more source

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