6512-57-8

Upstream product

• 2216-94-6 phenylpropynoic acid ethyl ester 
• 3406-03-9 2-(phenylsulfonyl)acetophenone 
• 141-05-9 Diethyl maleate 
• 31378-03-7 1-phenyl-2-tosylethanone 
• 100-52-7 benzaldehyde 
• 99-87-6 4-methylisopropylbenzene 

Relevant academic research and scientific papers

APEX Strategy Represented by Diels–Alder Cycloadditions—New Opportunities for the Syntheses of Functionalised PAHs

Diels–Alder cycloaddition of various dienophiles to the bay region of polycyclic aromatic hydrocarbons (PAHs) is a particularly effective and useful tool for the modification of the structure of PAHs and thereby their final properties. The Diels–Alder cycloaddition belongs to the single-step annulative π-extension (APEX) reactions and represents the maximum in synthetic efficiency for the constructions of π-extended PAHs including functionalised ones, nanographenes, and π-extended fused heteroarenes. Herein we report new applications of the APEX strategy for the synthesis of derivatives of 1,2-diarylbenzo[ghi]perylene, 1,2-diarylbenzo[ghi]perylenebisimide and 1,2-disubstituted-benzo[j]coronene. Namely, the so far unknown cycloaddition of 1,2-diarylacetylenes into the perylene and perylenebisimide bay regions was used. 1,2-Disubstituted-benzo[j]coronenes were obtained via cycloaddition of benzyne into 1,2-diarylbenzo[ghi]perylenes by using a new highly effective system for benzyne generation and/or high pressure conditions. Moreover, we report an unprecedented Diels–Alder cycloaddition–cycloaromatisation domino-type reaction between 1,4-(9,9-dialkylfluoren-3-yl)-1,3-butadiynes and perylene. The obtained diaryl-substituted core-extended PAHs were characterised by DFT calculation as well as electrochemical and spectroscopic measurements.

Rhenium-catalyzed synthesis of indenones by novel dehydrative trimerization of aryl aldehydes via C-H bond activation

By heating aryl aldehydes with catalytic amounts of a rhenium complex, ReBr(CO)5, and N-phenylacetamide in toluene, indenone derivatives are obtained in good to excellent yields. This reaction proceeds via (1) the formation of an isobenzofuran derivative by the insertion of an aldehyde into the C-H bond of another aldehyde (C-H bond activation) and successive intramolecular nucleophilic cyclization, (2) nucleophilic addition of the formed isobenzofuran derivative to the third aldehyde, (3) isomerization, and (4) intramolecular aldol condensation.

A novel multicomponent reaction of arynes, β-keto sulfones, and Michael-type acceptors: A direct synthesis of polysubstituted naphthols and naphthalenes

(Chemical Equation Presented) A novel multicomponent reaction of arynes, β-keto sulfones, and Michael-type acceptors is presented, providing an efficient method for the synthesis of polysubstituted naphthols and polysubstituted naphthalenes. Further investigation suggests that the tandem reaction may proceed via a sequential nucleophilic attack to arynes, intramolecular nucleophilic substitution followed by a Michael addition, and a ring closure - elimination process.

Reactions of some anellated 2-aminothiophenes with electron poor acetylenes

The reactivity of 2-aminothiophenes in two different anellations: (a) [b]-anellation to a saturated carbocycle and (b) [3,4-c]-anellation to benzopyrans, towards typical acetylenic dienophiles has been investigated. Because of the absence of conjugation, the thiophenes of type (a) do not undergo [4+2]-cycloaddition with acetylenic dienophiles. Instead, the N-vinylated products 2 and 3 were obtained with dimethyl acetylene dicarboxylate (DMAD). Electron poor alkynes react with the thiophenes of type (b) in three main ways: DMAD reacts in a [4+2]-mode in dioxane to give the products 7, 8 and 14; a Michael addition type reaction also takes place at the doubly vinylene homologous carbon atoms (C-1 in the starting materials 4, 9 and 10) in dioxane, methanol or ethanol. Methyl propiolate reacts in a similar way. The doubly N-vinylated product 26 was obtained from 10 in toluene and the C-1 vinylated products 24B and 27 were obtained from 9 in dioxane and 10 in methanol. The reaction of 10 with phenyl ethyl propiolate in dimethylformamide gave no addition product, instead a dimer of the acetylenic reagent was the isolated product. The accuracy of the assigned structures 5, 12 and 13a could be achieved on the basis of a single-crystal X-ray structure analysis of compound 13a. The reaction mechanism and the nature of the isolated products are dependent on the nature of the solvent. No addition reaction was observed between 17 and DMAD. The influence of the N-substitution on the nature of the addition (Michael or Diels-Alder) could be settled through the reactions of 18 and 21 with DMAD, which gave 19 and 14 (via 22), respectively as the only isolable products.