ChemInform Abstract: Catalytic Hydrogenation Causes C-Benzyl Bond Cleavage in 6-Amino-7,7-dibenzyl-2,4-dimethoxy-7H-pyrrolo[3,2-d]pyrimidine: An Example Indicating Novel Route to 6-Amino-7-benzyl-5H-pyrrolo[3,2-d]pyrimidines and Related Compounds.

ChemInform ◽  
2010 ◽  
Vol 29 (27) ◽  
pp. no-no
Author(s):  
M. OTMAR ◽  
M. MASOJIDKOVA ◽  
M. BUDESINSKY ◽  
A. HOLY
Keyword(s):  
Catalytic Hydrogenation ◽  
Bond Cleavage ◽  
Related Compounds

Synthesis and Ring Cyclization - Expansion - Contraction Reactions of Some New 2,2-Disubstituted Indan-1,3-diones and Related Compounds

2006 ◽  
Vol 59 (1) ◽  
pp. 59 ◽  
Author(s):  
Craig J. Roxburgh ◽  
Lee Banting
Keyword(s):  
Catalytic Hydrogenation ◽  
Pyridine Ring ◽  
Functional Group ◽  
Chemical Properties ◽  
Ring Expansion ◽  
Ring Structure ◽  
Side Reactions ◽  
The Third ◽  
Ring Expansion Reaction ◽  
Related Compounds

We have found that the hydrochloride of 2-phenyl-2-[2-(2-piperidyl)ethyl]-4,5,6,7-tetrahydroindan-1,3-dione 1 possesses marked analgesic activity (100% inhibition referenced to codeine) and report, as part of an extensive synthetic program, the synthesis of 38 new and structurally related compounds. Selective catalytic hydrogenation of the pyridine ring of 2-phenyl-2-[2-(2-pyridyl)ethyl]-indan-1,3-dione 2 yields the nine-membered nitrogen-containing heterocycle 6 by a novel ring cyclization–expansion reaction. The structural and functional group parameters required for this novel ring-expansion reaction have been extensively and thoroughly investigated through the synthesis of a series of structurally related compounds; principally by modification, substitution, and replacement of the various functionality contained within 2. In addition, we report the synthesis of a series of new 2-methyl-2-(ω-N-phthalimidoalkyl)-indan-1,3-diones 41, 45, and 53, two of which, like the parent 2-phenyl substituted indan-1,3-dione 2, also undergo a novel ring cyclization–expansion reaction to yield eight- and nine-membered nitrogen-containing rings. However, in these cases, further transannular reactions occur to produce the new 5,5- and 5,6-ring-fused nitrogen-containing heterocycles 44, 48 and 51, 52. Hydrazinolysis of the third, 2-methyl-2-(4-N-phthalimidobutyl)-indan-1,3-dione yields the new azepine-containing ring structure 56 by direct cyclization. Furthermore, some interesting and unexpected chemical properties of the final compounds, which include selective and non-selective pyridine-ring hydrogenations and a few unexpected side reactions, are described.

Synthesis of 5'-O-phosphonomethyl derivatives of pyrimidine 2'-deoxynucleosides

1990 ◽  
Vol 55 (10) ◽  
pp. 2521-2536 ◽  
Author(s):  
Marcela Krečmerová ◽  
Hubert Hřebabecký ◽  
Antonín Holý
Keyword(s):  
Sodium Salt ◽  
Catalytic Hydrogenation ◽  
Bond Cleavage ◽  
Diethyl Ester ◽  
Derivatives Of

Reaction of sodium salt of 3-N,3'-O-bis(benzyloxymethyl)-2'-deoxyuridine (X) and 3-N,3'-O-bis(benzyloxymethyl)-2'-deoxythymidine (XI) with diethyl p-toluenesulfonyloxymethanephosphonate in dimethylformamide afforded diesters of the respective 5'-O-phosphonomethyl derivatives XII and XVII. Diethyl esters of 5'-O-phosphonomethyl-2'-deoxynucleosides XV and XIX, obtained after hydrogenolytic removal of the benzyloxymethyl groups, were converted into free 2'-deoxy-5'-O-phosphonomethyluridine (XVI) and a mixture of anomeric 1-(2-deoxy-5-O-phosphonomethyl-β-D-erythro-pentofuranosyl)thymines (XXIIIa, XXIIIb), respectively. Analogously, 2'-deoxy-5'-O-phosphonomethylcytidine (XXXIV) was prepared from 4-N-benzoyl-2'-deoxy-3'-O-(tetrahydro-2H-pyran-2-yl) cytidine (XXX) via diethyl ester of 2'-deoxy-5'-O-phosphonomethylcytidine (XXXIII). This compound reacted with bromotrimethylsilane to give compound XXXIV without anomerization and nucleoside bond cleavage. Condensation of the protected nucleosides X and XI with dibenzyl p-toluenesulfonyloxymethanephosphonate afforded dibenzyl esters of the corresponding 5'-O-phosphonomethyl derivatives XIII and XVIII. The free 5'-O-phosphonomethyl derivatives XVI and XXIIIa were obtained from XIII and XVIII by catalytic hydrogenation.

Rhodium-Catalyzed Mono- and Divinylation of 1-Phenylpyrazoles and Related Compounds via Regioselective C−H Bond Cleavage

2009 ◽  
Vol 74 (18) ◽  
pp. 7094-7099 ◽  
Author(s):  
Nobuyoshi Umeda ◽  
Koji Hirano ◽  
Tetsuya Satoh ◽  
Masahiro Miura
Keyword(s):  
Bond Cleavage ◽  
Related Compounds

Nucleic acid related compounds. 78. Stereocontrolled syntheses of 6′(E and Z)-halovinyl analogues from uridine-derived vinylsulfones via vinyltin intermediates

1993 ◽  
Vol 71 (2) ◽  
pp. 192-198 ◽  
Author(s):  
Stanislaw F. Wnuk ◽  
Morris J. Robins
Keyword(s):  
Nucleic Acid ◽  
Trifluoroacetic Acid ◽  
Bond Cleavage ◽  
Lead Tetraacetate ◽  
Acetylenic Derivative ◽  
Vinyl Derivative ◽  
High Yields ◽  
Related Compounds

Treatment of the 6′(E)-tosylvinyl homonucleoside 1a with Bu3SnH/AIBN/toluene/Δ gave separable mixtures of 6′-vinylstannanes 2a(E/Z) in high yields. Stereospecific halodestannylations with N-iodosuccinimide, bromine, and N-bromosuccinimide proceeded smoothly to give the 6′(E or Z)-iodo(and bromo) vinyl compounds with retention of configuration. Chlorine or iodobenzene dichloride effected moderately stereoselective chlorodestannylation. Treatment of 2a with NH4F/MeOH/Δ resulted in carbon–tin bond cleavage to give the free vinyl derivative 4a. Aqueous trifluoroacetic acid effected concomitant protiodestannylation and deprotection of 2a to give 4b. Treatment of 2a(E) with lead tetraacetate/acetonitrile and deprotection afforded acetylenic derivative 3b.

Synthesis of several 4-hydroxy-3,5-dimethoxybenzamides, their O-substituted derivatives and some related compounds as potential neurotropic agents

1985 ◽  
Vol 50 (2) ◽  
pp. 510-518 ◽  
Author(s):  
Vladimír Valenta ◽  
Miroslav Protiva
Keyword(s):  
Blood Pressure ◽  
Catalytic Hydrogenation ◽  
Anticonvulsant Activity ◽  
Sodium Hydride ◽  
Antiemetic Agent ◽  
Related Compounds ◽  
Neurotropic Agents ◽  
Amino Ether

Reactions of 4-benzyloxy-3,5-dimethoxybenzoyl chloride with pyrrolidine, piperidine, morpholine and 1-methylpiperazine gave the amides IIIa-IIId which were debenzylated by catalytic hydrogenation on palladium. The 4-hydroxy-3,5-dimethoxybenzamides IVa-IVc were then treated with sodium hydride and 2-dimethylaminoethyl chloride to give the O-(2-dimethylaminoethyl)amides Va-Vc. The 3,4,5-trimethoxybenzamide IX was prepared as a homologue of the antiemetic agent "trimethobenzamide" (II) and reduced to the benzylaniline derivative X. The substituted nicotinamide XI was obtained from nicotinoyl chloride and 4-(2-diethylaminoethoxy)aniline. Out of the compounds prepared the amides IIId and Vc had some anticonvulsant activity, the piperazide IVd revealed a significant α-adrenolytic effect and the amino ether X reduced the blood pressure of normotensive rats.

Rhodium-catalyzed regioselective arylation of phenylazoles and related compounds with arylboron reagents via C–H bond cleavage

2008 ◽  
Vol 693 (14) ◽  
pp. 2438-2442 ◽  
Author(s):  
Sawako Miyamura ◽  
Hayato Tsurugi ◽  
Tetsuya Satoh ◽  
Masahiro Miura
Keyword(s):  
Bond Cleavage ◽  
Related Compounds

scholarly journals Exploring the effects of quantum decoherence on the excited-state dynamics of molecular systems

2021 ◽  
Vol 140 (4) ◽  
Author(s):  
Eric R. Heller ◽  
Jan-Ole Joswig ◽  
Gotthard Seifert
Keyword(s):  
Excited State ◽  
Potential Energy ◽  
Density Functional ◽  
Bond Cleavage ◽  
Minimum Energy ◽  
Quantum Decoherence ◽  
Ensemble Averaging ◽  
Excited State Dynamics ◽  
Complete Active Space ◽  
Related Compounds

AbstractFewest-switches surface hopping (FSSH) is employed in order to investigate the nonadiabatic excited-state dynamics of thiophene and related compounds and hence to establish a connection between the electronic system, the critical points in configuration space and the deactivation dynamics. The potential-energy surfaces of the studied molecules were calculated with complete active space self-consistent field and time-dependent density-functional theory. They are analyzed thoroughly to locate and optimize minimum-energy conical intersections, which are essential to the dynamics of the system. The influence of decoherence on the dynamics is examined by employing different decoherence schemes. We find that irrespective of the employed decoherence algorithm, the population dynamics of thiophene give results which are sound with the expectations grounded on the analysis of the potential-energy surface. A more detailed look at single trajectories as well as on the excited-state lifetimes, however, reveals a substantial dependence on how decoherence is accounted for. In order to connect these findings, we describe how ensemble averaging cures some of the overcoherence problems of uncorrected FSSH. Eventually, we identify carbon–sulfur bond cleavage as a common feature accompanying electronic transitions between different states in the simulations of all thiophene-related compounds studied in this work, which is of interest due to their relevance in organic photovoltaics.

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