Results 21 to 30 of about 51,454 (296)

Rate Dependence on Inductive and Resonance Effects for the Organocatalyzed Enantioselective Conjugate Addition of Alkenyl and Alkynyl Boronic Acids to β-Indolyl Enones and β-Pyrrolyl Enones

open access: yesMolecules, 2021
Two key factors bear on reaction rates for the conjugate addition of alkenyl boronic acids to heteroaryl-appended enones: the proximity of inductively electron-withdrawing heteroatoms to the site of bond formation and the resonance contribution of ...
Amy Boylan   +6 more
doaj   +1 more source

4,5,6,7-Tetrahydroindol-4-Ones as a Valuable Starting Point for the Synthesis of Polyheterocyclic Structures

open access: yesMolecules, 2021
This review focuses on the synthesis of polyheterocyclic structures with a variety of medicinal and optoelectronic applications, starting from readily available 4,5,6,7-tetrahydroindol-4-one analogs. First, routes toward the 4,5,6,7-tetrahydroindol-4-one
Tomas Horsten, Wim Dehaen
doaj   +1 more source

Pyrrole-Based Ti(III) and Ti(IV) PNP Pincer Complexes: Insertion of Ketones into the Ti(IV)-Phosphorus Bond

open access: yes, 2023
The synthesis, characterization, and reactivity of pyrrole-based Ti(III) and Ti(IV) PNP pincer complexes are described. [P(NH)P-iPr] (1) reacts with [TiCl4(THF)2] at room temperature in the presence of NEt3 to afford the Ti(IV) complex [Ti(PNPiPr)(Cl)3].
Gerald Tomsu (2861627)   +2 more
core   +2 more sources

{2,2′-[3-Azapentane-1,5-diylbis(nitrilomethylidyne)]dipyrrol-1-yl}(4-methylpyridine)cobalt(III) tetraphenylborate

open access: yesActa Crystallographica Section E, 2010
The title compound, [Co(C14H17N5)(C6H7N)](C24H20B) or [Co{(pyrrole)2dien}(4-Mepy)]BPh4 where (pyrrole)2dien is 2,2′-[(3-azapentane-1,5-diylbis(nitrilomethylidyne)]dipyrrole and 4-Mepy is 4-methylpyridine, contains a pentadentate (pyrrole)2dien ...
Mahmood Karimi Abdolmaleki   +3 more
doaj   +1 more source

Scientific Opinion on Flavouring Group Evaluation 77, Revision 1 (FGE.77Rev1): Consideration of Pyridine, Pyrrole and Quinoline Derivatives evaluated by JECFA (63rd meeting) structurally related to Pyridine, Pyrrole, Indole and Quinoline Derivatives evaluated by EFSA in FGE.24Rev2 (2013) [PDF]

open access: yesEFSA Journal, 2014
The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives
EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF)
doaj   +1 more source

Electrorheological properties of polypyrrole prepared by the action of mineral acids on pyrrole [PDF]

open access: yes, 1996
Polypyrrole was prepared in high yield by the polymerisation of pyrrole in strongly acidic conditions using hydrofluoric, hydrochloric (at 20°C and 100°C), hydrobromic, nitric and orthophosphoric acids.
Ratcliffe, Norman M.   +2 more
core   +1 more source

Pyrrole-Containing ABA Triblock Brush Polymers as Dual Functional Molecules to Facilely Access Diverse Mesostructured Materials

open access: yes, 2022
We report a new type of ABA-type brush-like triblock copolymer (PEGMA-b-PPHMA-b-PEGMA), which is characterized by two hydrophilic end segments (A) and a hydrophobic midblock (B) bearing polymerizable pyrrole moieties.
Hongwei Zhao (62620)   +8 more
core   +1 more source

Postdiagenetic Bacterial Transformation of Nickel and Vanadyl Sedimentary Porphyrins of Organic-Rich Shale Rock (Fore-Sudetic Monocline, Poland)

open access: yesFrontiers in Microbiology, 2021
Nickel and vanadyl porphyrins belong to the so-called fossil geo- or sedimentary porphyrins. They occur in different types of organic matter-rich sediments but mostly occur in crude oils and their source rocks, oil shales, coals, and oil sands.
Robert Stasiuk, Renata Matlakowska
doaj   +1 more source

UV Photodissociation of Pyrroles: Symmetry and Substituent Effects [PDF]

open access: yes, 2013
H (Rydberg) atom photofragment translational spectroscopy and ab initio electronic structure calculations are used to explore ways in which ring substituents affect the photofragmentation dynamics of gas phase pyrroles. S1
Marchetti, Barbara   +3 more
core   +1 more source

Dibromopyrrole Alkaloids from the Marine Sponge sp

open access: yesNatural Product Communications, 2009
Fourteen dibromopyrrole alkaloids were isolated from the marine sponge Acanthostylotella sp. collected in Indonesia. In addition to the known compounds 4,5-dibromo-N-(methoxy-methyl)-1 H -pyrrole-2-carboxamide ( 7 ), 4,5-dibromo-1 H -pyrrole-2 ...
Sherif Saeed Ebada   +4 more
doaj   +1 more source

Home - About - Disclaimer - Privacy