Photochemical reactions of a dimethacrylate compound containing a chalcone moiety in the main chain

We synthesized the new photosensitive oligomer containing a chalcone moiety in the main chain by end-capping reaction of diepoxide compound with methacrylic acid. The chalcone-epoxy oligomeric compound was synthesized with 4,4^′-dihydroxychalcone and epichlorohydrin. Investigation of the photosensitivity of the newly synthesized chalcone oligomer was carried out by using UV-Vis absorption and infrared spectroscopies under UV exposure. We observed the photodimerization behavior under UV irradiation. At the same time, we could also observe the photopolymerization of the compound with a trace amount of dimethoxyphenyl acetophenone. Thermal properties of UV-cured dimethacrylate compounds were also studied.     

含氧膦结构的可溶性感光聚酰亚胺合成与表征

聚酰亚胺(PI)是一类综合性能优异的功能性材料,广泛应用于航天、航空及电子工业等领域[1].感光聚酰亚胺可以采用光刻工艺,大大简化了其应用加工程序[2,3],因而备受人们所青睐.含查尔酮结构的聚合物对UV辐射敏感度高和化学稳定性好,最近被广泛的研究和应用[4～7].主链含查尔酮结     

Hydrqalumination of Diphenylacetylene

It was found that diphenylacetylene reacts at 55[ddot]C with i-Bu₂AlH to form cis-vinylalane. On the other hand, i-Bu₂AlH adds mostly in anti-manner to diphenylacetylene at 110[ddot] C.     

Synthesis and characterization of new 4,5-dihydropyrazol-1-yl derivatives

In this study, first, a series of chalcone compounds S1–S6 were synthesized from various acetophenone derivatives (acetophenone, p-methyl acetophenone, and p-methoxy acetophenone) and aromatic aldehyde derivatives (benzaldehyde, p-methyl benzaldehyde, and p-methoxy benzaldehyde) by the Claisen–Schmidt condensation reaction. These S1–S6 compounds were then used in the preparation of 4,5-dihydropyrazol-1-yl derivatives S7–S15. Finally, four new compounds S16–S19 were synthesized from compound (S7, S8, S9, and S12) and 2,4-dinitrophenylhydrazine. Therefore, three known and ten new heterocyclic compounds were synthesized and completely characterized using ¹H NMR, ¹³C NMR, IR, and elemental analysis.     

Synthesis and Characterization of a New Series of Hydroxy Pyrazolines

3-Phenyl-1-(thiophen-2-yl)prop-2-en-1-one obtained by Claisen–Schmidt condensation of 2-acetyl thiophene with benzaldehyde was converted into 2,3-dibromo-3-phenyl-1-(thiophen-2-yl)propan-1-one, which on treatment with various thiosemicarbazides in the presence of triethylamine in absolute ethanol, yielded the corresponding hydroxy pyrazolines 3a–h. All the compounds were characterized by IR, ¹H NMR, and ¹³C NMR spectra.     

Microwave-Assisted Michael Addition of Diethyl Malonate with Ferrocenyl Substituted Chalcones Under Solvent-Free Conditions

The article describes an efficient, economical, and environmentally friendly approach for Michael addition of diethyl malonate to ferrocenyl substituted chalcones in the presence of microwave irradiation under solvent-free conditions, affording the corresponding Michael adducts in moderate to good yields of 53–94%.

Efficient and Environmentally Friendly Approach to the Synthesis of Ferrocenyl‐Substituted 1,5‐Diketone Compounds Under Solvent‐Free Conditions

Abstract

This article describes a fast, efficient, economical, and environmentally friendly method for the preparation of a series of ferrocenyl‐substituted 1,5‐diketone compounds via Michael addition of ferrocenyl‐substituted chalcones with deoxybenzoin or dibenzyl ketone under solvent‐free conditions, and affords the corresponding Michael adducts with excellent yields of 77–93%.     

A facile synthesis of isoindoline and Δ-pyrrolines from chalcone and glycine by a cascade of process involving addition,in situ decarboxylation,and cyclization

In this Letter, we report a rapid one-step entry into isoindoline and Δ¹-pyrrolines from chalcone. The key step in the synthesis is the addition of glycine to chalcone. In acidic medium the reaction presumably goes through aza-Michael addition, whereas in basic medium the reaction proceeds through condensation followed by cyclization.     

An Easy Access to Oxime Ethers by Pd‐Catalyzed C—O Cross‐Coupling of Activated Aryl Bromides with Ketoximes and Chalcone Oximes

An efficient Pd‐catalyzed method for C—O cross‐coupling of ketoximes and chalcone oximes with activated aryl bromides and bromo‐chalcones has been developed. All oxime ethers were obtained in good to excellent yields by [(π‐allyl)PdCl]₂/tBuXPhos ( L7 ) catalyst system. TrixiePhos ( L11 ) was also found to be effective for the oxime coupling. This method offers an easy and smooth coupling of chalcone oximes with activated aryl bromides and bromo‐chalcones, which has not been previously explored.