Silver- and gold-mediated domino transformation: a strategy for synthesizing benzo[e]indolo[1,2-a]pyrrolo/pyrido[2,1-c][1,4]diazepine-3,9-diones

We reported a strategy for the synthesis of fused heterocyclic compounds benzo[e]indolo[1,2-a]pyrrolo/pyrido[2,1-c][1,4]diazepine-3,9-diones via an AgSbF(6)/gold-complex catalyzed one-pot cascade transformation. The strategy is tolerant of a broad range of substrates and affords a series of intriguing fused diazepinedione heterocycles.     

Annulation reaction of methyl 2-(benzo[b][1,4]thiazin-3-ylidene)acetate with β-nitrostyrenes and 3-nitrochromenes

The acid catalyzed domino reaction of β-nitrostyrenes with methyl 2-(benzo[b][1,4]thiazin-3-ylidene)acetate, which were previously prepared from the cyclization of 2-aminobenzenethiol and methyl 4-chloroacetoacetate, resulted in 2-arylbenzo[b]pyrrolo[1,2-d][1,4]thiazine-3-carboxylates in high yields. Under same reaction conditions, the similar reaction with 3-nitrochromenes afforded corresponding benzo[b]chromeno[4′,3':4,5]pyrrolo[1,2-d][1,4]thiazine derivatives in good yields.     

Intramolecular N-arylation in heterocyclization: synthesis of new pyrido-fused pyrrolo[1,2-a][1,4]diazepinones

Alkylation of l-prolinamide with 3-(chloromethyl)-2-halopyridines, followed by cyclization through an intramolecular Pd-catalysed amidation, provided an entry to the pyrido[2,3-e]pyrrolo[1,2-a][1,4]diazepin-10-one scaffold. Furthermore, a synthetic route towards diverse new pyrido[f]pyrrolo[1,2-a][1,4]diazepin-7-ones has been developed by acylation of contiguously substituted (aminomethyl)halopyridines with Boc-l-proline followed by intramolecular amination.     

One-step assembly of novel carbamoyl substituted 6-oxo-4,5,6,11-tetrahydropyrrolo[1,2-b][2,5]benzodiazocine

In this work we have synthesized novel pharmaceutically relevant pyrrolo[1,2-b][2,5]benzodiazocines based entirely on the use of MCR between heterocyclic aldehyde-acid, amines, and isonitriles. The developed synthetic strategy provides an efficient one-step route to rare heterocyclic scaffold of paramount interest.     

Facile synthesis of 6,12b-diaza-dibenzo[a,h]azulen-7-ones and benzo[f]pyrrolo[1,2-a][1,4]diazepin-4-ones via CuI/l-proline catalyzed intramolecular N-arylation

Facile intramolecular N-arylation catalyzed by CuI/l-proline has been developed to prepare 6,12b-diaza-dibenzo[a,h]azulen-7-ones and benzo[f]pyrrolo[1,2-a][1,4]diazepin-4-ones in good to excellent yields.     

New four-component Ugi-type reaction. Synthesis of heterocyclic structures containing a pyrrolo[1,2-a][1,4]diazepine fragment

[reaction: see text] We present a convenient synthesis of novel heterocyclic structures containing pyrrolo[1,2-a][1,4]diazepine fragment using a novel modification of four-component Ugi condensation. We demonstrate the usefulness and versatility of the developed approach for the synthesis of variously substituted compounds and discuss the scope and limitations of the chemistry involved.     

A novel practical synthesis of pyrrolo[1,2-a]thieno[2,3-e][1,4]diazepines

In an investigation of new heterocyclic systems, a novel way to obtain pyrrolo[1,2-a]thieno[2,3-e][1,4]diazepine 8 was effected by ring closure to the appropriate nitroaldehyde compound which was synthesized in five steps from 3-bromomethyl-2-nitrothiophene 1 .     

Furo[3,2-e]pyrrolo[1,2-α][1,4]diazepine and derivatives

The 5,10-dihydro-4H-furo[3,2-e]pyrrolo[1,2-α][1,4]diazepin-5-one ( 7 ) and furo[3,2-e]pyrrolo[1,2-α][1,4]diaze-pine ( 10 ) are synthesized from suitable isocyanates 3a,b in acetic acid. The reactivity of 10 (C- and N-alkyla-tion) is investigated.     

Ring-contraction from benzo[b][1,4]thiazines to benzo[d]thiazolines induced by oxygen

An unexpected ring-contraction from benzo[b]pyrazino[1,2-d][1,4]thiazine-1,4-diones (6) to benzo[4,5]thiazolo[3,2-a]pyrazine-1,4-diones (7) has been developed. The preliminary mechanistic studies showed the transformation contained two independent steps: the first step is the formation of a Michael adduct upon the addition of the protic solvent, in the presence of base, to the C-2-C-3 double bond of compound 6, and the second step is a ring-contraction induced by oxygen via the migration of sulfur atom from C-2 to C-3 position. And its scope is also studied.     

Synthesis of 5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepine and 10,11-dihydro-5H,12H-pyrrolo[2,1-c][1,4]benzodiazocine derivatives via cyclization of 2-aminomethylpyrroles

We have synthesized pyrrolo[1,2-α][1,4]benzodiazepine 6 and pyrrolo[2,1-c][1,4]benzodiazocines 12 and 13 from the corresponding 1-arylpyrrole 1d and 1-benzylpyrroles 7a and 7b by routes involving four and five steps, respectively.     

New synthetic approaches to polycyclic aromatic hydrocarbons and their carcinogenic oxidized metabolites: derivatives of benzo[s]picene, benzo[rst]pentaphene, and dibenzo[b,def]chrysene

A new synthetic approach to polycyclic aromatic compounds is described that entails in the key steps double Suzuki coupling of PAH bisboronic acid derivatives with o-bromoaryl aldehydes to furnish aryl dialdehydes that are converted to larger polycyclic aromatic ring systems by either (a) conversion to diolefins by Wittig reaction followed by photocyclization or (b) reductive cyclization with triflic acid and 1,3-propanediol. This synthetic method provides convenient access to as many as three different polycyclic aromatic ring systems from a single Suzuki coupled intermediate. It was utilized to synthesize substituted derivatives of benzo[s]picene, benzo[rst]pentaphene, dibenzo[b,def]chrysene, and 13,14-dihydro-benz[g]indeno[2,1-a]fluorene, as well as the putative carcinogenic bisdihydrodiol metabolites of benzo[s]picene, benzo[rst]pentaphene, and dibenzo[b,def]chrysene.     

Polycondensed nitrogen heterocycles. VII. 5,6-Dihydro-7-h-pyrrolo[1,2-D]-[1,4] benzodiazepin-6-ones. A novel series of annelatcd 1,4-benzodiazepines

The synthesis of a novel class of annelated 1,4-benzodiazepinen, the 2-R-3 methyl-5,6-dihydro-7H-pyrrolo[1,2-d][1,4]benzodiazepin-6-ones (Ve-e), is described. The reaction of 2-(o-aminophenyl)-3-R-5-methylpyrroles(IIIa,b) with bromoacetyl bromide in the presence of triethylamine produced the title compounds. An alternative synthetic route was achieved by means of the reactions of 1a,b with the appropriated α-aminoacids. The catalytic reduction of IVe-e over 10% palladium on charcoal led in good to excellent yields directly to the formation of pyrrolo[1,2-d]-[1,4]benzodiazepines (Ve-e).     

Synthesis of novel imidazo[1,2-a]pyrrolo[2,1-c][1,4]benzodiazepines and pyrimido[1,2-a]pyrrolo[2,1-c][1,4]benzodiazepines

Several 1 1-amino-5H-pyrrolo[2,1-c][1,4]benzodiazepines have been used as starting material to prepare a number of derivatives of 9H-imidazo[1,2-a]pyrrolo[2,1-c][1,4]benzodiazepines and 10H-pyrimido[1,2-a]pyrrolo[2,1-c][1,4]benzodiazepines. The imidazole nucleus was built by reaction of amidines with ethyl bromopyruvate or aminoacetaldehyde dimethylacetal. Several derivatives of imidazo[1,2-a]pyrrolo[2,1-c][1,4]benzodiazepine have been prepared by formylation of the pyrrole ring followed by formation of thioamides. Condensation of 11-amino-5H-pyrrolo[2,1-c][1,4]benzodiazepines with diethyl ethoxymethylenemalonate afforded intermediate diesters which were transformed into the corresponding 10H-pyrimido[1,2-a]pyrrolo[2,1-c]-benzodiazepines.     

New derivatives and ring systems of annulated pyrrolobenzo[1,4]diazepines

(S)-11-Thioxo-2,3,11,11a-tetrahydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-5(10H)-one was subsequently reacted with amino acid esters and base to give new 6:7:5:5, 6:7:5:6, and 6:5:7:7 ring systems. The 6:7:5:5 ring system, (S)-11,12,13,13a-tetrahydro-2H-benzo[e]imidazo[2,1-c]pyrrolo[1,2-a][1,4]diazepine-3,9-dione, exhibits a considerable CH-acidity at position 2, which was exploited in Knoevenagel reactions, a Wittig reaction, enol ester formations, and methylations.     

Synthesis,Physical Properties and Memory Device Application of a Twelve‐Ring Fused Twistheteroacene

Developing new organic conjugated materials for high density memory devices is highly desirable. In this research, a novel donor–acceptor‐type twelve‐ring fused twistheteroacene, 2,7,19,24‐tetra‐tert ‐butyl‐13,30‐didodecyl‐9,17,26,34‐tetraphenyl benzo[8′,9′]triphenyleno[2′,3′:7,8]dibenzo[b,e][1,4]dioxino[1,2,3,4‐lmn]dibenzo[6′,7′:10′,11′]tetraceno[2′,3′:5,6][1,4]dioxino[2,3‐f][3,8]phenanthroline‐12,14,29,31(13H ,30H )‐tetraone ( DPyN ) has been synthesized and characterized. It displays high thermal stability, possesses a broad absorption band centered at 510 and 538 nm, and emits red fluorescence in organic solvents. A solution‐processed memory device with DPyN as an active element shows an excellent memory performance with an ON/OFF current ratio of 10^3.46:1 and a threshold voltage of −2.44 V.     

Condensed isoquinolines. 37.* Heterocyclization using 3-(arylamino)- and 3-(hetarylamino)isoquinolin-1(2H)-ones

The reaction of 3-NHR-isoquinolin-1(2H)-ones (R = Ar) with aromatic aldehydes in the presence of Me3SiCl or in acetic acid leads to the formation of derivatives of dibenzo[b,f][1, 8]naphthyridin-5(6H)- one and benzo[f]isoquino[3,4-b][1, 8]naphthyridine-5,9(6H,7H)-dione. The reaction for R = Het in the presence of Me3SiCl gives derivatives of 5H-pyrido[1',2':1,2]pyrimido[4,5-c]isoquinolin-5-one, benzo[f]isoquinoline[3,4-b][1,8]naphthyridine-5,9[6H,7H]-dione, and derivatives of new heterocyclic systems, 5H-pyrazino[1',2':1,2]pyrimido[4,5-c]isoquinolin-5-one, 5H-[1,3]thiazolo[3',2':1,2]pyrimido- [4,5-c]isoquinolin-5-one, 5-H-benzo[f]pyrazolo[3,4-b][1,8]naphthyridin-5-one, and isoquino[3,4-b]- [1,5]naphthyridin-5(6H)-one. The effect of the structure of substituent R and nature of the substituent in the benzaldehydes on the structure of the reaction products was studied.     

An efficient approach to azirino and pyrrolo-fused dibenzazepines. Conformations of substituted dibenzo[c,f]pyrrolo[1,2-a]azepines

An effective approach to azepino-fused heterocycles is described. trans-1-Aryl-7,11b-dihydro-1H-azirino[1,2-a]dibenzo[c,f]azepines were synthesised via a domino sequence: isomerization of gem-dichloroaziridine-intramolecular Friedel-Crafts acylation of the tethered benzene ring catalysed by SnCl(4) and subsequent hydride induced intramolecular cyclization. Cycloaddition of dibenzazepinium ylides, generated by heating these aziridines, to activated C[double bond]C, C[triple bond]C dipolarophiles and fullerene C(60), leads to derivatives of dibenzo[c,f]pyrrolo[1,2-a]azepine. The reaction proceeds with complete stereoselectivity via cycloaddition of only W-ylide, which due to the high barrier does not undergo E,Z-isomerization under the reaction conditions. It was found that 2,3,9,13b-tetrahydro-1H-dibenzo[c,f]pyrrolo[1,2-a]azepine systems can exist in conformations of two types depending on the substituents at the pyrrolidine carbons in β-position with respect to nitrogen. Details of cycloaddition reactions and the conformational behavior of cycloadducts were studied by DFT calculations at the B3LYP/6-31G(d) level.     

Hydrazonoyl Halides Precursors to Synthesis of New Thiazole,Thiadiazole, and Benzothiazepine Derivatives

New series of substituted thiazole and thiadiazoles were prepared starting from N ′‐(3,4‐dihydronaphthalen‐1(2H )‐ylidene)hydrazinecarbothiohydrazide by reacting with different types of hydrazonoyl chlorides. In addition, 7‐(4‐chlorophenyl)‐5,6,6a,7‐tetrahydrobenzo [b ]naphtha‐[1,2‐e ][1,4]thiazepine reacted with hydrazonoyl halides to afford a new derivatives of 7‐(4‐chlorophenyl)‐14‐phenyl‐5,6,6a,7‐tetrahydro‐16H‐benzo[b]naphtho[1,2‐e][1,2,4]triazolo[4,3‐d ][1,4]thiazepine. Structures of the newly synthesized compounds were elucidated on the basis of elemental analyses and spectral data.     

Chichibabin-type condensation of cyclic ketones with 3-R-1,2,4-triazin-5(4H)-ones

Reactions between substituted 1,2,4-triazines and ketones were investigated. General procedures for one-pot synthesis of hydrogenated derivatives of such polycyclic systems as benzo[c][1,2,4]triazino[1,6-a][2]azecine, [1,2,4]triazino[1,6-f]phenantridine, and dicyclopenta[b,d]pyrido[1,2-f][1,2,4]triazine are described.     

Synthesis of isoindolo[2,1-a]quinoline derivatives and their effects on N2-induced hypoxia

A variety of isoindolo[2,1-a]quinoline derivatives as well as the following related heterocycles have been prepared: 11b,12-dihydro-5H-isoindolo[2,1-b][2]benzazepine-7,13-dione (8a), 7,8,14,14a-tetrahydroisoindolo[2,1-c][3]benzazocine-5, 13-dione (8b), 6a,7-dihydroisoquinolino[2,3-a]quinoline-5,12-dione (12), 2,3,3a-4-tetrahydropyrrolo[1,2-a]quinoline-1,5-dione (14), and pyrido[2',3':3,4]pyrrolo[1,2-a]quinoline-5,11(5H)-dione (17). The key synthetic step involves an intramolecular Friedel-Crafts reaction of acid chlorides such as isoindole-1-acetyl chlorides (4), the acids (3) of which were prepared starting with 2-arylisoindole-1,3(2H)-diones (2-arylphthalimides) (1). The protective effects of isoindolo[2,1-a]quinoline derivatives (19 and 20) against N2-induced hypoxia were examined. Among them, 6-(diethylaminomethyl)isoindolo[2,1-a]quinoline-5,11(5H)-dio ne (19b) showed the most potency.