Synthesis of 5‐Acyl‐2‐Amino‐3‐Cyanothiophenes: Chemistry and Fluorescent Properties

Abstract

Independent of the substrate structure and reaction conditions, 3-amino-2-cyanothioacrylamides, which contain two active electrophilic centers, were shown to interact with various active halo methylene compounds under mild conditions to afford 5-acyl-2-amino-3-cyanothiophenes as the only products. A series of new polyfunctional thiophene derivatives with a rare combination of functionalities were synthesized, and their photophysical properties were experimentally and computationally investigated. The calculated electronic characteristics of the ground and excited states were compared to the experimental results, which provided a good understanding of the relationship between the optoelectronic properties and the molecular structures. After absorption of light quanta, the systems populate an intramolecular charge-transfer (ICT) Franck-Condon state, and emission occurs from a twisted ICT minimum.

Cyanothioacetamides as a synthetic platform for the synthesis of aminopyrazole derivatives

“…Considering that the construction of the pyrazole cycle can be carried out by the interaction of hydrazine with 1,3-bielectrophilic reagents, we paid attention to the structure of 2-cyanothioacetamides 1 and 3-amino-2-cyanoprop-2-enethioamides 2 [ 22 ] which combine in one molecule cyano- and thioamide groups, as well as a fragment of enamine, each in principle being capable of interaction with hydrazine ( 3a ) ( Figure 2 ).…”

Fluorescent Assembles of 2‐Amino‐3‐cyanothiophenes with Azoles. Design and Peculiar Properties of Absorption and Emission

“…Recently, we published a series of articles, on the new method for synthesis of the functionalized thiophenes with unique combination of the substituents [4] . Efficient, two‐step procedure allowed to obtained thiophenes possessing remarkable photophysical properties (λ em =443–475 nm, quantum yield (QY)=0.2–6.6%, SS=59–109 nm) and showing aggregation‐induced emission (AIE) and aggregation‐induced emission enhancement effect (AIEE) [4a–d] . It is known that with regard to photoactivity or biological activity, fused thiophenes heteroaromatic systems or their assemblies are more attractive than monocyclic compounds, because of the wider potential for varying their biological and physicochemical characteristics owing to the opportunities provided by the presence of two (or more) rings possessing specific electronic and spatial structure.…”

A química do ranelato: aspectos fundamentais da estrutura eletrônica e reatividade

“…As representações dos orbitais HOMO, H-1, H-2, LUMO, L+1 e L+2 podem ser visualizadas na Figura 34. Diversos estudos usando cálculos DFT [113][114][115][116][117][118] (com diferentes funcionais e bases) para espécies derivadas do tiofeno mostram orbitais de fronteira muito semelhantes aos calculados Borin e colaboradores [119] usando métodos multiconfiguracionais de cálculo.…”