Electron-Deficient Benzo[de]isoquinolino[1,8-gh]quinoline Diamide π-Electron Systems

Synthetically versatile electron-deficient π-electron systems are urgently needed for organic electronics, yet their design and synthesis are challenging due to the low reactivity from large electron affinities. In this work, we report a benzo[de]isoquinolino[1,8-gh]quinoline diamide (BQQDA) π-electron system. The electron-rich condensed amide as opposed to the generally-employed imide provides a suitable electronic feature for chemical versatility to tailor the BQQDA π-electron system for various electronic applications. We demonstrate an effective synthetic method to furnish the target BQQDA parent structure, and highly selective functionalization can be performed on bay positions of the π-skeleton. In addition, thionation of BQQDA can be accomplished under mild conditions. Fine-tuning of fundamental properties and supramolecular packing motifs are achieved via chemical modifications, and the cyanated BQQDA organic semiconductor demonstrates a high air-stable electron-carrier mobility.     

Synthesis of Substituted Tricyclo[5.3.1.04,9]undecan‐2,6‐dione from 4,4‐Disubstituted Cyclohexanone Enamines and Methacryloyl Chloride

Morpholine enamines 4‐acetyl‐4‐methyl‐1‐morpholinocyclohexene 4a, 4‐acetyl‐4‐phenyl‐1‐morpholinocyclohexene 4b, and 4‐acetyl‐4‐isopropenyl‐1‐morpholinocyclohexene 4c react with methacryloyl chloride to give 1,7‐dimethyl‐4(N‐morpholino) tricyclo[5.3.1.0^4,9]undecan‐2,6‐dione 9a , 1‐phenyl‐7‐methyl‐4(N‐morpholino) tricyclo[5.3.1.0^4,9]undecan‐2,6‐dione 9b , and 1‐ispropenyl‐7‐methyl‐4(N‐morpholino) tricyclo[5.3.1.0^4,9]undecan‐2,6‐dione 9c respectively, along with the corresponding substituted adamandane‐2,4‐diones.     

Nickel‐Catalyzed Electrochemical Synthesis of Dihydro‐Benzo[b]thiophene Derivatives

Abstract

The intramolecular electrochemical reductive cyclization of ortho‐haloaryl allyl thioethers catalyzed by Ni(II) complexes associated to cyclam ligands affords dihydro‐benzo[b]thiophene derivatives in moderate to good yields.     

Synthesis of Some Novel 2,3,4,8,9‐Pentahydro‐7‐(4‐haloaryl)‐pyrazolo[5,1‐e]benzo[1,5]oxazocines and 2,3(erythro), 7,8‐Tetrahydro‐2‐aryl‐3‐(4‐fluoro‐3‐methylbenzoyl)‐6‐(4‐haloaryl)pyrazolo[5,1‐d] Benzo[1,4]oxazepines via Solid–Liquid PTC

In this communication, a simple and straightforward procedure for the heterocyclization of 1H‐4,5‐dihydro‐3‐(4‐haloaryl)‐5‐substituted phenylpyrazoles (4) with 1‐bromo‐3‐chloropropane and 2,3‐dibromo‐1‐(4‐fluoro‐3‐methylphenyl)‐3‐phe‐ nylpropanone affording 2,3,4,8,9‐pentahydro‐7‐(4‐haloaryl)pyrazolo[5,1‐e]benzo[1,5] oxazocines 5 and regioselective synthesis of 2,3(erythro),7,8‐tetrahydro‐2‐ aryl‐3‐(4‐fluoro‐3‐methylbenzoyl)‐6‐(4‐halophenyl)pyrazolo[5,1‐d]benzo[1,4]oxa‐ zepines 6, respectively, via solid–liquid PTC is reported. All the synthesized compounds have been characterized on the basis of their spectral studies (IR, PMR, and MS) and analytical data.     

Reduction of 3‐Acyl Derivatives of Oxindoles,Benzo[b]furan‐2‐ones,and Benzo[b]thiophen‐2‐ones to the Corresponding Alkyl Derivatives by Sodium Borohydride–Acetic Acid

It was found that 3‐acyl derivatives of oxindoles, benzo[b]furan‐2‐ones, and benzo[b]thiophen‐2‐ones could be efficiently and conveniently reduced to the corresponding alkyl derivatives by pelletized sodium borohydride in acetic acid. A typical procedure involves heating the acylated substrates for approximately 90 min in a slurry of glacial acetic acid and sodium borohydride to provide the 3‐alkyl product in yields ranging from 62% to 96%. This synthetic methodology represents a convenient approach to the synthesis of the alkyl derivatives.     

Synthesis of Benzo[b]benzo[2,3‐d]thiophen‐6,9‐diones via Palladium(II) Acetate–Mediated Cyclization of 5‐Arylthiocyclohexa‐2,5‐diene‐1,4‐diones

Palladium(II)‐mediated oxidative cyclization of 5‐arylthiocyclohexa‐2,5‐diene‐1,4‐diones 4 giving biologically important benzo[b]benzo[2,3‐d]thiophene‐6,9‐diones 2 has been performed with a stoichiometric amount of palladium(II) acetate in distillated acetic acid.     

Synthesis of [125I]‐, [2H]‐, and [3H]‐Labeled 3‐Iodothyronamine (T1AM)

3‐Iodothyronamine (T₁AM) is a novel metabolite of thyroid hormone. In HEK‐293 cells expressing an orphan G‐protein coupled receptor, the trace amine receptor, T₁AM, potently increased cAMP accumulation. In mice, T₁AM rapidly induced hypothermia and bradycardia within minutes of administration. These results suggest the existence of a new signaling pathway, the stimulation of which leads to rapid physiological and behavioral consequences. Isotope‐labeled T₁AM derivatives would be useful to study the biology and pharmacology of T₁AM. Herein we describe efficient syntheses of [¹²⁵I]‐, [²H]‐, and [³H]‐T₁AM.     

Microwave‐Assisted Facile Synthesis and Crystal Structure of cis‐9,10,11,15‐Tetrahydro‐9,10[3′,4′]‐furanoanthracene‐12,14‐dione

A facile synthesis and crystal structure of cis‐9,10,11,15‐tetrahydro‐9,10[3′,4′]‐furanoanthracene‐12,14‐dione from the reaction of anthracene and maleic anhydride in xylene in a short time and high yield using a modified commercial domestic microwave oven is reported.     

Synthesis of Fused Tetrazolo[1,5‐c] pyrrolo[3,2‐e]pyrimidines and Their Reductive Conversion to New 4‐Aminopyrrolo[2,3‐d]pyrimidines

Some new 7,9‐substituted 7H‐1,2,3,4‐tetrazolo[1,5‐c]pyrrolo[3,2‐e]pyrimidines 5 have been synthesized either by diazotization of 4‐hydrazino‐5,7‐disubstituted‐7H‐pyrrolo[2,3‐d]pyrimidines 4 obtained by hydrazinolysis of 4‐chloro‐5,7‐disubstituted 7H‐pyrrolo[2,3‐d]pyrimidines 3 or via a substitution reaction between 3 and sodium azide. 5,7‐Disubstituted‐7H‐pyrrolo[2,3‐d]pyrimidin‐4(3H)‐ones 2 were obtained by cyclocondensation of 1,4‐disubstituted 2‐amino‐3‐cyanopyrroles 1 with formic acid, which, on chlorination using phosphorus oxychloride, afforded 3. 2‐Amino‐3‐cyanopyrroles 1 were synthesized from the reaction between (2-bromo-1-(4-fluorophenyl) ethylidene) propanedinitrile and substituted aromatic amines under Gewald reaction conditions. A novel route for the synthesis of 4‐amino‐5,7‐disubstituted‐7H‐pyrrolo[2,3‐d]pyrimidines 6 by the reductive ring cleavage of 5 has been reported.     

Preparation and Stereochemistry of the Isopropylidene Derivatives of 1,2‐Dihydronaphtho[2,1‐b]Furan‐1,2‐Diol and 1,2,9,10‐Tetrahydronaphtho[2,1‐b:7,8‐b′] Difuran‐1,2,9,10‐Tetraol in Comparison with the Corresponding Acetyl Derivatives

Abstract

1,2‐Dihydronaphtho[2,1‐b]furan‐1,2‐diol and 1,2,9,10‐tetrahydronaphtho[2,1‐b:7,8‐b′]difuran‐1,2,9,10‐tetraol were transformed into the corresponding isopropylidene derivatives, which were studied mainly by ¹H NMR and chiral HPLC analyses in terms of a possible transformation mechanism and stereochemistry in comparison with their corresponding acetyl derivatives.     

Design and Syntheses of Novel Calix[4]crown: Calix[4]‐Dixanthates‐Crowns

Abstract

A series of novel calix[4]‐dixanthates‐crowns were designed and synthesized by the “1 + 1 condensation” of reacting calix[4]‐1,3‐dixanthate salts derivative (4) with polyethylene glycol ditosylates in 40–60% yields. It was found that the new calixcrowns showed outstanding complexation abilities towards soft cations. Calix[4]‐dixanthate‐crown‐4 (5b) exhibited high complexation selectivity towards Ni²⁺.     

Synthesis and Amphiphilic Behavior of N,N‐Bis‐glucosyl‐1,5‐benzodiazepin‐2,4‐dione

Abstract

Glucosyl‐1,5‐benzodiazepin‐2,4‐diones were synthesized in order to study the influence of the glucidic moiety on the amphiphilic behaviour. The glucosyl groups include 6‐deoxy‐D‐glucopyranos‐6‐yl and 6‐deoxy‐3‐O‐R‐D‐glucopyranos‐6‐yl (R = n ? C _n H _2n+1; n = 1, 8, 10 and 12). Variation in the length of the hydrocarbon chain allowed comparison of such amphiphilic data as water solubility (Sw) and surface tension (γ) values. At 25°C, the glucopyranosyl benzodiazepines with R = H and CH₃ show a higher water solubility than the starting 1,5‐benzodiazepin‐2,4‐diones. Some other glucidic benzodiazepine derivatives with an appropriate alkyl chain at C‐3 carbon of the D‐glucopyranose present a variable hydrosolubility and surface tension γ values close to 43 to 46 mN · m^?1 at the corresponding saturation. Moreover, according to preliminary tests, these compounds seem to show a better affinity for the blood brain barrier.     

SbCl3‐Al2O3–Catalyzed,Solvent‐Free,One‐Pot Synthesis of Benzo[b]1,4‐diazepines

This article explores the use of antimony(III) chloride adsorbed on neutral alumina as an efficient catalyst for the one‐pot synthesis of benzo[b]1,4‐diazepines (83–94%) under solvent‐free conditions. The process is easy, efficient, ecofriendly, and economical.     

Efficient Microwave‐Assisted Synthesis of 9,9‐Bis[4‐(2‐hydroxyethoxy)phenyl]fluorene from 9‐Fluorenone and 2‐Phenoxyethanol

9‐Fluorenone (1) smoothly reacts with phenoxyethanol (2) in the presence of Al³⁺‐montmorillonite catalyst and 3‐mercaptopropionic acid as a cocatalyst under microwave irradiation at 160°C for 10 min to give 9,9‐bis[4‐(2‐hydroxyethoxy)phenyl]fluorene (3) in 81% yield, which was much higher than the yield of 33% obtained by conventional heating using an oil bath. A similar acceleration effect of microwave irradiation was observed in other metal‐cation‐exchanged montmorillonite catalysts as well.     

Synthesis of Novel Classes of Pyrido[2,3‐d]‐pyrimidines,Pyrano[2,3‐d]pyrimidines,and Pteridines

6‐Amino‐5‐formyluracils 1 and 5‐formyl‐6‐hydroxyuracils 4 react with Meldrum's acid 2 in the presence of piperidine as catalyst under thermolytic conditions to afford 6‐carboxy‐2,4,7‐trioxopyrido[2,3‐d]pyrimidines 3 and 6‐carboxy‐2,4,7‐trioxopyrano[2,3‐d]pyrimidines 5 in good yield. Under identical conditions, 6‐amino‐5‐nitrosouracils 6 react with 2 to afford pteridine‐6‐carboxylic acids 7 in good yields.     

Rapid Synthesis of 3‐Aminoimidazo[1,2‐a]Pyridines and Pyrazines

p‐Toluenesulfonic acid catalyzed the one‐pot, three‐component synthesis of 3‐aminoimidazo[1,2‐a]pyridines and pyrazines through a condensation reaction of a 2‐aminoazine, an aldehyde, and an isocyanide at room temperature. This methodology affords a number of 3‐aminoimidazo[1,2‐a]pyridines in reasonable yields and short reaction times without any significant optimization of the reaction conditions.     

Studies in Thio‐Claisen Rearrangement: Regioselective Synthesis of Thiopyrano[2,3‐b]pyran‐2‐ones and Thieno[2,3‐b]pyran‐2‐ones

Abstract

4‐Mercapto‐6‐methyl‐2‐pyrone was alkylated with different allylic and propargylic halides under phase transfer catalyzed condition in the presence of TBAB or BTEAC catalyst in chloroform–aqueous NaOH (1%) at room temperature. The S‐alkylated thiopyran‐2‐ones were then refluxed in quinoline or in chlorobenzene to give 4‐chloromethylthiopyrano[2,3‐b]pyran‐2‐one and 4‐hydroxymethylthiopyrano[2,3‐b]pyran‐2‐one or several thieno[2,3‐b]pyran‐2‐ones.     

Synthesis and Antimicrobial Activity of 1‐[(Substituted Carbamoyl)Amino]‐1H,3H‐1λ5‐[1,3,2]oxazaphospholo[3,4‐a]benzimidazol‐1‐ones

1‐[(Substituted carbamoyl)amino]‐1H,3H‐1λ⁵‐[1,3,2]oxazaphospholo[3,4‐a]benzimidazol‐1‐ones were synthesized by reacting benzimidazole 2‐methanol (4) with different chlorides of carbamidophosphoric acids (3) in the presence of triethylamine at 40–45°C. Their ¹H, ¹³C, and ³¹P NMR spectral data were discussed. The title compounds were tested for their activity against the fungi Aspergillus niger and Fusarium solani and bacteria Staphylococcus aureus and Escherichia coli. These compounds showed moderate antibacterial activity when compared with antifungal activity.     

“Golden” Cascade Cyclization to Benzo[c]-Phenanthridines

Herein, we describe a gold-catalyzed cascade cyclization of Boc-protected benzylamines bearing two tethered alkyne moieties in a domino reaction initiated by a 6-endo-dig cyclization. The reaction was screened intensively, and the scope was explored, resulting in nine new Boc-protected dihydrobenzo[c]phenanthridines with yields of up to 98 %; even a π-extension and two bidirectional approaches were successful. Furthermore, thermal cleavage of the Boc group and subsequent oxidation gave substituted benzo[c]phenanthridines in up to quantitative yields. Two bidirectional approaches under the optimized conditions were successful, and the resulting π-extended molecules were tested as organic semiconductors in organic thin-film transistors.     

Convenient One‐Pot Protocol for an Exclusive Synthesis of 4‐Cyano/ethoxycarbonyl‐2,2‐dimethyl‐2H‐chromene and/or 3‐Cyano/ethoxycarbonyl‐2‐isopropyl‐benzo[b]furan from a Single Oxo‐ylide

[{2‐(Fluoroaryloxy)‐2‐methyl‐propanoyl}‐(cyano/ethoxycarbonyl) methylene]triphenylphosphoranes underwent microwave‐assisted tandem intramolecular Wittig and Claisen rearrangement and internal cyclization reactions to afford fluoro‐substituted 2,2‐dimethyl‐2H‐chromenes and/or 2‐isopropyl‐benzo[b]furans in good yield. Upon controlled microwave irradiation in the presence of Nafion H catalyst in xylene, the oxo‐ylides selectively formed 4‐cyano/ethoxycarbonyl‐2,2‐dimethyl‐2H‐chromenes. Microwave irradiation of the same oxo‐ylide in the presence of K₂CO₃ as catalyst or in a polar solvent–like sulfolane resulted in the exclusive formation of the corresponding fluoro‐substituted 3‐cyano/ethoxycarbonyl‐2‐isopropyl‐benzo[b]furans.