Results 21 to 30 of about 3,457 (280)

Triazolopyridines 21.1 The stereochemistry of 1-[1,2,3]triazolo[1,5-a] pyridin-7-yl-4-(2H-[1,2,3]triazol-4-yl)-1,3-butadienes and triazolo ring opening derivatives

open access: yesARKIVOC, 2002
The synthesis and NMR study of the geometry of 1-[1,2,3]triazolo[1,5-a]pyridin-7-yl-4-(2H- [1,2,3]triazol-4-yl)-1,3-butadienes 1a, 1b, 5 and of new 1-(6-substituted-2-pyridyl)-4-(2H- [1,2,3]triazol-4-yl)-1,3-butadienes 8-10 is reported.
Belén Abarca   +2 more
doaj   +2 more sources

NHeterocyclic Carbene Stabilized 1Bora-1,3-butadienes

open access: yes, 2021
Deprotonation of [(NHC)­(Fmes)­B-allyl]+ borenium cations (NHC, IMes (a) or IMe2 (b); Fmes, 2,4,6-(CF3)3C6H2) provides an easy entry to the NHC-stabilized 1-bora-1,3-butadienes. They feature a planar s-trans-conformation just like 1,3-butadiene.
Gerhard Erker   +7 more
core   +1 more source

In vitro and in vivo mutagenicity of the butadiene metabolites butadiene diolepoxide, butadiene monoepoxide and diepoxybutane [PDF]

open access: yesMutagenesis, 1997
Three metabolites of 1,3-butadiene, namely butadiene diolepoxide, butadiene monoepoxide and diepoxybutane, were tested in the bacterial mutation assay using Salmonella typhimurium strain TA100 with and without metabolic activation (S9 mix). All three compounds showed a mutagenic response. The bifunctional epoxide was more effective than the diolepoxide
I D, Adler   +3 more
openaire   +2 more sources

Rotational Barrier and Conjugation: Theoretical Study of Resonance Stabilization of Various Substituents for the Donors NH2 and OCH3 in Substituted 1,3-Butadienes

open access: yesIndonesian Journal of Chemistry, 2019
The barrier to internal rotation around the central C2–C3 single bond of a series of (1E)-monosubstituted 1,3-butadienes and (1E,3E)-1-Y-4-X-disubstituted butadienes, with Y=NH2 or OCH3 and X=NO2, CHO, COOH, CN, CF3, Cl or F, were studied at the density ...
Ali Hussain Yateem
doaj   +1 more source

Sequential Transformations of 1,3-Dibora Butadienes to Enones or Tetrasubstituted 1,3-Butadienes

open access: yes, 2016
Sequential Transformations of 1,3-Dibora Butadienes to Enones or Tetrasubstituted 1,3 ...
Guillaume Desurmont (3038538)   +3 more
core   +1 more source

Racemic and Asymmetric Diels−Alder Reactions of 1-(2-Oxazolidinon-3-yl)-3-siloxy-1,3-butadienes

open access: yes, 2016
Achiral and chiral 1-(2-oxazolidinon-3-yl)-3-siloxy-1,3-butadienes were prepared from readily available starting materials. Although more stable than the parent 1-amino-3-siloxy dienes, the 1-(2-oxazolidinon-3-yl)-3-siloxy-1,3-butadienes are still very ...
Jacob M. Janey (1831201)   +3 more
core   +1 more source

New Heterocyclic Precursors for Thermal Generation of Reactive, Electron-Rich 1,2-Diaza-1,3-butadienes

open access: yes, 2016
The preparation and thermolysis of new stable heterocyclic precursors of 1,2-diaza-1,3-butadienes is described. The resulting reactive diazadienes are trapped in situ with N-phenyldiazamaleimide.
Jessica E. Reed (2723554)   +2 more
core   +1 more source

Intermolecular Diels–Alder Cycloaddition/Cross-Coupling Sequences of 2‑Bromo-1,3-butadienes

open access: yes, 2020
2-Bromo-1,3-butadienes are demonstrated to be effective substrates for tandem Diels–Alder/transition metal cross-coupling reaction sequences. Intermolecular cycloaddition of a 2-bromo-1,3-diene with activated dienophiles proceeded under Lewis acid ...
Hans Choi (8366853)   +7 more
core   +1 more source

Optimization of the Production of Rubber Compounds Using Mathematical Models

open access: yesAdvanced Engineering Materials, EarlyView.
Rubber compounds were mixed in a batch internal mixer, and symbolic regression was used to derive mathematical models linking recipe and process parameters to ram path, torque, and mixing quality (incorporation, dispersion, distribution). Subsequent optimization with evolutionary algorithms identified operating conditions that reduce specific energy ...
Anke Bardehle   +7 more
wiley   +1 more source

Broadly Effective Enantioselective Diels−Alder Reactions of 1-Amino-substituted-1,3-butadienes

open access: yes, 2016
A broad range of substituted 1-amino-1,3-butadienes undergo enantioselective Diels−Alder reactions with methacrolein in the presence of 5 mol % of Cr(III)-salen complex 1.
Tetsuo Iwama (2145706)   +2 more
core   +1 more source

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