Fused Pyrrole Ring Research Articles

Methyl 6-methyl-1-oxo-2,3,4,9-tetrahydrocarbazole-2-carboxylate

The carbazole unit of the title mol­ecule, C15H15NO3, is not planar. The dihedral angle between the benzene ring and the fused pyrrole ring is 0.53 (2)°. The cyclo­hexene ring is in half-chair form. The methyl ­acetate group at position 2 has a equatorial orientation. In the crystal structure, the mol­ecules are stabilized by inter­molecular N—H⋯O and C—H⋯O hydrogen bonds.

Efficient Synthesis of Trisubstituted [1]Benzopyrano[4,3‐b]pyrrol‐4(1H)‐one Derivatives from 4‐Hydroxycoumarin.

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Efficient synthesis of trisubstituted [1]benzopyrano[4,3- b]pyrrol-4(1 H)-one derivatives from 4-hydroxycoumarin

Various trisubstituted [1]benzopyrano[4,3- b]pyrrol-4(1 H)-one derivatives have been synthesized from 4-hydroxycoumarin with a 30–40% yield over six steps. The key step of the synthesis is a base-promoted intramolecular cyclization of enamines 5 , followed by dehydration to generate the fused pyrrole ring.

Confusion, Inversion, and Creation — A New Spring from Porphyrin Chemistry

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Synthesis and photochemistry of Ru(II) complexes containing phenanthroline-based ligands with fused pyrrole rings.

Hydrolysis of 1,10-phenanthrolinopyrrole ethyl ester leads to the acid derivative which is unstable at room-temperature releasing CO(2) and forming 1,10-phenanthrolinopyrrole (php). The ligand reacts with ruthenium(II) to form a series of complexes of the general formula [Ru(php)(n)(bpy)(3-n)](2+), where bpy = 2,2'-bipyridine and n = 1-3. The photochemical properties reveal that the complexes have longer-lived excited states than the standard complex, [Ru(bpy)(3)](2+). Their emission lifetimes range from 9.04 micros (n = 1) to 35.5 micros (n = 3) at 77 K compared to 7.57 micros for the standard. Similarly, at room-temperature, emission lifetimes range from 1.20 micros (n = 1) to 1.70 micros (n = 3) relative to the standard (0.56 micros). The emission quantum yields also have higher values than the standard [Ru(bpy)(3)](2+) under similar conditions. The temperature-dependent studies for the complexes establish the distribution among the radiative, nonradiative, and (3)MLCT to (3)d-d decay channels and are in agreement with the energy gap law.

Confusion, inversion, and creation--a new spring from porphyrin chemistry.

This article mainly deals with the recent serendipity of novel porphyrin analogs such as N-confused porphyrin. The unique property of this ligand allows the formation of a variety of metal complexes. The important aspect of dynamic flipping (inversion), induced either by confusion or expansion of the macrocyclic core, that leads to the generation of new porphyrinoids, is emphasized. This review concludes with the recent progress on expanded porphyrins bearing confused, inverted, and fused pyrrole rings.

A new and versatile synthesis of 5-substituted pyrrolo[2,3- d]pyrimidines

We have developed a new methodology for the construction of 5-substituted pyrrolo[2,3- d]pyrimidines that involves the reduction of a nitroalkane to an oxime using the reducing ability of the Sn(SR 3) − species, followed by mild, acid-catalysed deoximation of the resulting adduct using Dowex-H + resin to form an intermediate aldehyde that spontaneously cyclises to the fused pyrrole ring.

Exploitation of a new route to fused pyrroles: Synthesis of TNP-351, homo-MTA and 5-arylpyrrolo[2,3- [formula omitted]]pyrimidines

We have developed a new methodology for the construction of pyrrolo[2,3- d ]pyrimidines that involves Michael addition of 2,6-diamino-4(3 H )-pyrimidinone or 2,4,6-triaminopyrimidines to nitroolefins, followed by a Nef reaction of the resulting adduct to form an intermediate aldehyde that spontaneously cyclizes to the fused pyrrole ring. This methodology has been exploited in a new synthesis of TNP-351, and for the first reported preparation of homo-MTA and of a series of 5-arylpyrrolo[2,3- d ]pyrimidines.

Synthesis of a 1,3,4,5-tetrahydrobenz[ cd]indole via the Vicarious Nucleophilic substitution of hydrogen

Two approaches to synthesis of 6-methoxy-1,3,4,5-tetrahydrobenz[ cd]indol-4-amine 1 were developed Indolic precursor 21 of the tricyclic system was prepared via the VNS reaction, but attempts to execute the C ring closure failed. The other strategy, based on eleboration of the VNS product 30 to a tetrahydronaphtalene system followed with formation of the fused pyrrole ring, proved successful

ChemInform Abstract: A Novel Synthesis of Compounds Containing a Fused Pyrrole Ring from Cyclic Ketones and N‐BOC‐L‐Phenylalaninal.

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A novel synthesis of compounds containing a fused pyrrole ring from cyclic ketones and N-BOC-L-phenylalaninal

A synthesis of fused pyrrole-containing compounds from N-Boc-L-phenylalaninal and cyclic ketones is described.

Novel selective heterocyclization of the Michael adducts of ene-hydrazines with dimethyl acetylenedicarboxylate

Cyclization of the Michael adducts 1 and 6 formed from ene-hydrazines and dimethyl acetylenedicarboxylate (DMAD) in the presence of polyphosphoric acid (PPA) produced the fused 1,2-diazepine rings 2 and 7. However, the adducts when heated in 1,2,3,4-tetrahydronaphthalene (tetralin) preferentially provided the fused pyridone rings 4 and 10 and the fused pyrrole rings 5 and 11.