A Modular Synthesis of Unsymmetrical Tetraarylazadipyrromethenes
摘要:
A stepwise route to unsymmetrical tetraarylazadipyrromethenes by a condensation of 2,4-diaryl-5-nitroso-pyrroles with 2,4-diarylpyrroles is described. This modular building-block approach allows for the introduction of up to four different aryl substituents on the azadipyrromethene and is tolerant of a varied substituent set. An efficient synthesis of the 2,4-diarylpyrroles building blocks from 1,3-diaryl-4-nitro-butan-1-ones by nitro hydrolysis to a keto-aldehyde and subsequent ammonia condensation reaction has been achieved. The facile conversion of 2,4-diarylpyrroles into their alpha-nitroso analogues by their reaction with sodium nitrite generated the second building block required for the synthesis.
Reaction between 4-Nitro-1,3-diarylbutan-1-ones and Ammonium Acetate in the Presence of Morpholine and Sulfur: An Efficient Synthesis of 2,4-Diarylpyrroles
An efficient synthesis of 2,4-diarylpyrroles is described. Heating a mixture of a 4-nitro-1,3-diarylbutan-1-one and ammoniumacetate in the presence of morpholine and sulfur afforded the corresponding 2,4-diarylpyrroles in excellent yields.
The present invention relates to novel photopolymer formulation comprising a polyol component, a polyisocyanate component, a writing monomer and a photoinitiator comprising a dye of formula (I).
The present invention further relates to a holographic medium which contains a photopolymer formulation of the present invention or is obtainable by using same, to the use of a photopolymer formulation of the present invention for producing holographic media and also to a process for producing a holographic medium by using a photopolymer formulation of the present invention.
The present invention relates to novel photopolymer formulation comprising a polyol component, a polyisocyanate component, a writing monomer and a photoinitiator comprising a dye of formula (I).
The present invention further relates to a holographic medium which contains a photopolymer formulation of the present invention or is obtainable by using same, to the use of a photopolymer formulation of the present invention for producing holographic media and also to a process for producing a holographic medium by using a photopolymer formulation of the present invention.
Synthesis of 3,4‐Dihydro‐2
<i>H</i>
‐Pyrroles from Ketones, Aldehydes, and Nitro Alkanes via Hydrogenative Cyclization
作者:Barbara Klausfelder、Patricia Blach、Niels de Jonge、Rhett Kempe
DOI:10.1002/chem.202201307
日期:2022.8.22
developed and employed for the synthesis of 3,4-dihydro-2H-pyrroles via hydrogenation and subsequent cyclization of nitro ketones. The catalyst was identified from a library of 24 heterogeneous catalysts. The key to our hydrogenation/cyclization reaction is the tolerance of aldehydes and ketones as functional groups and the ability to hydrogenate aliphaticnitrocompounds efficiently.
Enantiomerically pure carbamate-monoprotected trans-cyclohexane-1,2-diamines are used as chiral organocatalysts for the addition of aryl ketones and acetone to nitroalkenes to give enantioenriched beta-substituted gamma-nitroketones. The reaction was performed in the presence of 3,4-dimethoxybenzoic acid as an additive, in chloroform as the solvent at room temperature, achieving enantioselectivities up to 96%. Theoretical calculations are used to justify the observed sense of the stereoinduction. (C) 2015 Elsevier Ltd. All rights reserved.