Solid Phase Synthesis of β-Carbolines

Much attention has been paid to carbolines in recent years, owing to the wide range of their biological activity 1. Many papers have reported the synthesis and reactivity of carbolines2,3. Generally there are two ways to synthesize carbolines. One is through the Bischler-Napieralski reaction, and the other through Pictet-Spengler reaction. In the former method, the reaction of carboxylic acids with tryptophan using PPE or POCl3 as the condensing agent give dihydro-?-carbolines, which are c…     

Facile and Efficient One-Pot Synthesis of β-Carbolines

Initial formation of tetrahydrocarboline 3 from tryptophan methyl ester 1 and aldehyde 2 by Pictet–Spengler reaction, followed by treatment with trichlorocyanuric acid, provides a facile and efficient route for a one-pot synthesis of β-carbolines with excellent yields.     

Synthesis of Some C‐4 Hydroxybenzo[c]pyrans: A New Approach

A new synthetic approach to the synthesis of some epimeric C‐4‐hydroxy‐benzo[c]pyrans is described. A key step in their formation is stereoisomerisation of a nonconjugated ortho alkenylphenylketone and ‐ester using palladium bisacetonitrile [bisacetonitriledichloropalladium(II)] to give the corresponding conjugated E stereoisomers which cyclize on treatment with meta‐chloroperbenzoic acid (m‐CPBA) to afford the target compounds.     

Effective Synthesis of β-Ketophosphonate Derivatives of Calix[4]resorcinolarenes

An effective method for introduction of -phosphonate fragments to a calix[4]resorcinolarene matrix is presented octa(ketophosphonate)calix[4]resorcinolarenes are prepared. The effectiveness of 2,8,14,20-tetramethyl-4,6,10,12,16,18,22,24-octa[3-(dimethoxyphosphoryl)-2-oxopropyl]calix[4]-resorcinolarene for extraction of lanthanum ions from water to chloroform in the presence of picrate ions, accompanied by formation of a complex is demonstrated.     

Synthesis of Some Novel Fluorinated Pyrazolo[3,4‐b]Pyridines

Abstract

Reaction of 5‐amino‐3‐substituted pyrazoles (1a–c) and 5‐amino‐1,3‐disubstituted pyrazoles (1d–i) with fluorinated‐β‐diketones (2) results in the formation of the single isomer of pyrazolo[3,4‐b]pyridines (4a–h). A one‐pot procedure for the synthesis of title compounds starting from α‐cyanoacetophenones along with a possible mechanistic pathway for the formation of the title compounds is described.     

Novel Method for the Synthesis of [1,2,4]Triazino[4,3‐c]quinazoline System

4‐Hydrazinoquinazoline was found to form new 2‐(3,4‐dihydro‐3oxo‐2H‐[1,2,4]triazino[4,3‐c]quinazolin‐4‐yl)acetic acid with maleic anhydride in on‐step sequence. Proposed heterocyclization includes, probably, acylation reaction followed by intramolecular uncleophilic addition.     

Efficient Synthesis of Some Unsaturated [1,2,3]‐Triazole‐Linked Glycoconjugates

Thermal 1,3‐dipolar cycloaddition of ethyl 4‐azido‐2,3,4‐trideoxy‐α‐D‐erythro‐hex‐2‐enopyranosides with diethyl acetylenedicarboxylate or copper‐catalyzed reaction with various functionalized alkynes gave the corresponding 1‐(ethyl 2,3,4‐trideoxy‐α‐D‐erythro‐hex‐2‐enopyranosid‐4‐yl)‐1H‐1,2,3‐triazole derivatives in quite good yields. These unsaturated compounds could be transformed into 1‐(ethyl 2,3‐di‐O‐acetyl‐4‐deoxy‐α‐D‐mannopyranosid‐4‐yl)‐1H‐1,2,3‐triazoles by a simple dihydroxylation reaction. Copper‐catalyzed condensation of ethyl 6‐O‐acetyl‐4‐azido‐2,3,4‐trideoxy‐α‐D‐erythro‐hex‐2‐enopyranoside with 1,3,5‐triethynylbenzene or 1,3,5‐tris(prop‐2‐ynyloxy)benzene afforded the corresponding trivalent glycoconjugate clusters.     

Heterocyclic Synthesis with Nitriles: Synthesis of Some New Thiophene,Pyridazine, Oxazine,Thiopyran, Pyrrole,and Pyrrolo[1,2‐b]pyridazine Derivatives

2‐Phenyl‐1,1,3‐tricyanopropene[α‐(cyanomethyl)benzylidene‐malononitrile] undergoes bromination with N‐bromosuccinimide (NBS) to afford 2‐phenyl‐1,1,3‐tricyano‐3‐bromopropene: [α(bromocyanomethyl)benzylidene malononitrile]. This bromo derivative undergoes reactions with sodium hydrogen sulfide, hydrazine hydrate, phenyl hydrazine, hydroxylamine hydrochloride, ethyl thioglycollate, urea derivatives, and cyanacetohydrazide to afford thiophene, 4H‐pyridazines, 4H‐oxazine and 4H‐thiopyran, N‐substituted pyrrole, and pyrrolo[1,2‐b]pyridazine derivatives respectively.     

Synthesis of [60] Fullerene-Podophyllotoxin Derivative

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Synthesis of 2,3,4,7-tetrahydro[1,4]thiazepines from thiazolidines and β-enaminonitriles

A wide library of 2,3,4,7-tetrahydro[1,4]thiazepines have been prepared by simple heating of thiazolidine and β-enaminonitrile derivatives in acetonitrile. The procedure, whose yields depend on the nature and position of the substituents, gave good results if the substituents were not very bulky but it is less effective when starting from 2-substituted thiazolidines.     

Synthesis and Some Transformations of Derivatives of Pyrido[3,2-b]indole (δ-Carboline)

The reactions of 2-dimethyliminomethyl-3-(p-nitrophenyl)aminoindole chloride with compounds with an active methylene center have been studied. A series of derivatives of -carboline have been synthesized. By the reaction of 3-ethoxycarbonyl-2-methyl-1-p-nitrophenylpyrido[3,2-b]indolinium chloride with the diethyl acetal of DMF the corresponding 2-dimethylaminovinyl derivative was synthesized which was converted into 5-p-nitrophenyl-1-oxo-1,10-dihydropyrano[3',4':5,6]pyrido[3,2-b]indol-5-ium chloride in the presence of acid.     

Synthesis of β-Cyclodextrin-[60]fullerene Conjugate and Its DNA Cleavage Performance

A water soluble β-cyclodextrin (β-CD) functionalized [60]fullerene (C60-CD) was synthesized.The C60-CD-induced generation of reactive oxygen species (ROS),and DNA-cleavage ability and cytotoxicity of C60-CD were studied upon visible light irradiation,demonstrating that the compound is very promising in the applications of photodynamic therapy.The histological analyses demonstrate that C60-CD has no acute or subacute toxicity to living body.     

Synthesis of 3,4-Bis (4′-Methylphenyl) Thieno [2,3-b]Thiophene: First Example of Peri-Diaryl Thienothiophene

3,4-bis(4′-methylphenyl) thienothiophene, the first example of peri-(3,4) diaryl thienothiophene has been synthesized by a sequence involving preparation of ketene dithioacetal, Dieckmann type cyclization, ester hydrolysis and decarboxylation.     

Heterocyclizations of Di- and Tricarbonyl Indole Derivatives. Synthesis of β-Carbolines, 3H-[1,2,5]Triazepino-[5,4-a]indol-4(5H)-one,and 5,10-Dihydro[1,2]diazepino-[4,5-b]indol-4(3H)-one

Russian Journal of Organic Chemistry - A synthetic approach to β-carbolines has been proposed on the basis of heterocyclization of ethyl 2-(2-benzoyl-1H-indol-3-yl)acetate with...     

Unexpected Recyclization of 1H-δ-Carbolines to Pyrrolo[1,2-a]indoles

When 1H-2-methyl-1-p-nitrophenyl-3-ethoxycarbonylpyrido[3,2-b]indole (1) is heated in alcoholic solutions of ammonia, we observe a previously unknown recyclization leading to formation of 2-alkoxycarbonyl-3-methyl-9-p-nitrophenylimino-9H-pyrrolo[1,2-a]indoles (3,6).     

Cyclopenta[b]thienyl Ligand in Organometallic Chemistry. Synthesis of Cyclopenta[b]thiophene η5-Complexes with Metal Coordination at the Thiophene Ring

Unlike isoelectronic ⁶-indenyl ruthenium, manganese, and chromium complexes, heating of Mn(CO)₅OTf, [Ru(Cp^*)Cl₄], and Cr(C₁₀H₈)(CO)₃ with isomeric 2-ethyl-5-methylcyclopenta[b]thiophenes leads to the corresponding ⁵-complexes where the metal is coordinated at the C₅-carbocycle. The structure of the complex Mn(Th)(CO)₃ (Th = 2-ethyl-5-methylcyclopenta[b]thienyl) was proved by X-ray analysis.     

Synthesis of selenium-containing biindolyls and their Diels–Alder reaction toward the synthesis of heteroannulated [a]- and [c]-carbazoles

We reported the first syntheses of 2- and 3-(2-(benzo[b]selenophen-2-yl)-indoles and their Diels–Alder reactions to furnish six unique annulated benzoselenphene carbazoles. This facile route can be used to synthesize selenium-containing biindolyl derivatives that possessed potential pharmaceutical activities.     

New Approach to Synthesis of Tetrahydroisoquino[2,1-c] [1,3]benzodiazepine

A concise and efficient synthesis of the new compounds tetrahydroisoquino [2,1-c] [1,3]benzodiazepine 5 and 7 is reported.     

Gold(I)-Catalyzed Benzylic C(sp3)−H Functionalizations: Divergent Synthesis of Indole[a]- and [b]-Fused Polycycles**

Phenyl azides substituted by an (alkylphenyl)ethynyl group facilitate benzylic sp³(C−H) functionalization in the presence of a JohnPhosAu catalyst, resulting in indole-fused tetra- and pentacycles via divergent N- or C-cyclization. The chemoselectivity is influenced depending on the counter-anion, the electron density of the α-imino gold(I) carbene, and the alkyl groups stabilizing the benzylic carbocation originating from a 1,5-hydride shift. An isotopic labeling experiment demonstrates the involvement of an indolylgold(I) species resulting from a tautomerization that is much faster than the deauration. The formation of a benzylic sp³(C−H) functionalization leading to an indole-fused seven-membered ring is also demonstrated.