scholarly journals Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones

2016 ◽  
Vol 12 ◽  
pp. 301-308 ◽  
Author(s):  
Ping Qian ◽  
Bingnan Du ◽  
Wei Jiao ◽  
Haibo Mei ◽  
Jianlin Han ◽  
...  
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Good Yield ◽  
Oxidative Reaction ◽  
Reaction Proceeds

An oxidative reaction for the synthesis of 4-alkyl-substituted dihydroisoquinolin-1(2H)-ones with N-allylbenzamide derivatives as starting materials has been developed. The radical alkylarylation reaction proceeds through a sequence of alkylation and intramolecular cyclization. The substituent on the C–C double bond was found to play a key role for the progress of the reaction to give the expected products with good chemical yields. Additionally, N-methacryloylbenzamides were also suitable substrates for the current reaction and provided the alkyl-substituted isoquinoline-1,3(2H,4H)-diones in good yield.

Reactions of 4-Pyrones with Azomethine Ylides as a Chemo­selective Method for the Construction of Multisubstituted Pyrano[2,3-c]pyrrolidines

Synthesis ◽  
2021 ◽  
Author(s):  
Dmitrii L. Obydennov ◽  
Vyacheslav D. Steben’kov ◽  
Konstantin L. Obydennov ◽  
Sergey A. Usachev ◽  
Vladimir S. Moshkin ◽  
...  
Keyword(s):  
Double Bond ◽  
Ring Opening ◽  
Azomethine Ylides ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Computational Studies ◽  
Carbon Double Bond ◽  
Reactivity Indexes ◽  
Reaction Proceeds

Abstract4-Pyrones bearing electron-donating and electron-withdrawing groups react with nonstabilized azomethine ylides to form pyrano[2,3-c]pyrrolidines in moderate to good yields. The reaction proceeds chemoselectively as a 1,3-dipolar cycloaddition of the azomethine ylide at the carbon–carbon double bond of the pyrone activated by the electron-withdrawing substituent. The reactivity of 4-pyrones toward azomethine ylides was rationalized by computational studies with the use of reactivity indexes. The pyrano[2,3-c]pyrrolidine moiety could be modified, for example by a ring-opening transformation under the action of hydrazine to provide pyrazolyl-substituted pyrrolidines.

The reaction between 2,3-Diphenyl-2H-azirine and Phenyldiazomethane

1973 ◽  
Vol 26 (11) ◽  
pp. 2547 ◽  
Author(s):  
JH Bowie ◽  
B Nussey ◽  
AD Ward
Keyword(s):  
Double Bond ◽  
Good Yield ◽  
Alternative Synthesis

The reaction between 2,3-diphenyl-2H-azirine and phenyldiazomethane produces the stable 1-azido-1,2,3-triphenylprop-1-ene in good yield. The structure is confirmed by an alternative synthesis which indicates that the double bond has the E-configuration.

Reductions with Sulfurated Borohydrides. VII. Reactions with Epoxides

1971 ◽  
Vol 49 (24) ◽  
pp. 4047-4053 ◽  
Author(s):  
J. M. Lalancette ◽  
A. Frêche
Keyword(s):  
Good Yield ◽  
Basic Solution ◽  
Improved Method ◽  
Reaction Proceeds

The reaction of NaBH2S3 with epoxides gives symmetrical bis-(2-hydroxyethyl) disulfides. The stereochemistry of the reaction is similar to the attack of H2S on the epoxides in basic solution. Substituted epoxides are opened from the less hindered side. The reaction proceeds with good yield and is general. An improved method of preparation of the 1,2-mercaptols is presented.

Diversity-Oriented Synthesis via Catalyst-Free Addition of Ketones to [e]-Fused 1H-Pyrrole-2,3-diones

Synthesis ◽  
2018 ◽  
Vol 50 (24) ◽  
pp. 4897-4904 ◽  
Author(s):  
Ekaterina Stepanova ◽  
Andrey Maslivets ◽  
Svetlana Kasatkina ◽  
Maksim Dmitriev
Keyword(s):  
Intramolecular Cyclization ◽  
Aromatic Hydrocarbons ◽  
Michael Addition ◽  
Aldol Reaction ◽  
Synthetic Approach ◽  
Reaction Conditions ◽  
Diversity Oriented Synthesis ◽  
Catalyst Free ◽  
Solvent Free Conditions ◽  
Reaction Proceeds

A facile synthetic approach towards two distinct pyrrole-based heterocyclic scaffolds has been developed by the interaction of 1H-pyrrole-2,3-diones fused at the [e]-side to a 1,4-benzoxazin-2-one or quinoxalin-2(1H)-one moiety with ketones. The described interaction proceeds either as an aldol reaction or as a Michael addition/intramolecular cyclization depending on the reaction conditions. The disclosed aldol reaction proceeds with good diastereoselectivity under catalyst-free conditions when the reaction is carried out in aromatic hydrocarbons. Products of the cascade Michael addition/intramolecular cyclization reaction are predominantly formed under catalyst-free and solvent-free conditions. The proposed strategy provides facile access to pharmaceutically interesting pyrrole-based polyheterocycles.

Model Compounds Related to Saquayamycin. Attempts to Oxygenate the A/B Ring Junction

2002 ◽  
Vol 55 (5) ◽  
pp. 343 ◽  
Author(s):  
M. A. Apponyi ◽  
J. H. Bowie ◽  
B. W. Skelton ◽  
A. H. White
Keyword(s):  
Double Bond ◽  
Maleic Anhydride ◽  
Good Yield ◽  
Ring Opening ◽  
Diels Alder ◽  
Aromatic System ◽  
Model Compounds ◽  
Similar Treatment ◽  
Ring Junction

The aim of this project was to attempt to find a method for introducing the cis-dihydroxyl substitution at the A/B-ring junction of model compounds related to the saquayamycins. The Diels-Alder reactions of maleic anhydride and bromomaleic anhydride with 5,5-dimethyl-3-vinylcyclohexa-1,2-dienyl acetate gave the two required endo-adducts in good yield, namely (octahydrobenzo[e]isobenzofuran-9-yl acetate (6) and (octahydrobenzo[e]isobenzofuran-9-yl acetate (9). Each of these was converted into the B-ring mono-epoxide, namely (H-benzo[e]oxireno-2,3-furan-1-yl acetate (7) and a mixture of two racemic diastereoisomers of 9a-bromo-3,3-dimethyl-7,9-dioxoperhydrobenzo[e]oxi- reno[2,3-f]isobenzofuran-1-yl acetate (12), respectively. It was then hoped to deprotonate both (7) and (12) at the 9a position in order to effect migration of the 8,9 double bond to the 9,9a position. Reaction of (7) with a mild base (pyridine) did not effect any reaction. Similar treatment of (12) did remove the 9a proton, but it also effected ring opening of the epoxide, followed by dehydration and dehydrobromination to give an excellent (but unwanted) yield of the aromatized system (±)-7,7-dimethyl-1,3-dioxo-1,3,5,7-tetrahydrobenzo (e]isobenzofuran-9-yl acetate. Dehydrobromination of (9), and deprotonation of the 9a position, similarly formed the aromatic system (e]isobenzofuran-9-yl acetate (11) in good yield.

scholarly journals Intramolecular Cyclization of Ruthenium Vinylidene Complexes with a Tethering Vinyl Group:  Facile Cleavage and Reconstruction of the C−C Double Bond

2007 ◽  
Vol 129 (48) ◽  
pp. 14974-14980 ◽  
Author(s):  
Cheng ◽  
Yi-Chun Kuo ◽  
Shu-Hao Chang ◽  
Ying-Chih Lin ◽  
Yi-Hong Liu ◽  
...  
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Vinylidene Complexes ◽  
Vinyl Group

Expeditious Scalable Catalyst-Free One-Pot Synthesis of 4-Alkoxy-5-amino-3-methylthiophene-2-carbonitriles via Sequential Reactions­ of Lithiated Alkoxyallenes with Isothiocyanates and 2-Bromoacetonitrile

Synthesis ◽  
2018 ◽  
Vol 50 (09) ◽  
pp. 1891-1900 ◽  
Author(s):  
Nina Nedolya ◽  
Boris Trofimov ◽  
Olga Tarasova ◽  
Alexander Albanov
Keyword(s):  
Intramolecular Cyclization ◽  
Thiophene Ring ◽  
One Pot ◽  
One Pot Synthesis ◽  
Convenient Approach ◽  
Reaction Proceeds ◽  
Sequential Addition ◽  
In Situ Formation ◽  
Cyano Groups

A synthetically simple and convenient approach to tetrasubstituted thiophenes with rare combination of the alkoxy, amino, and cyano groups has been developed. The assembly of polyfunctionalized thiophene ring is implemented in one preparative step by sequential addition of isothiocyanate and 2-bromoacetonitrile to the lithiated (with n-BuLi) alkoxyallene. The reaction proceeds through in situ formation and intramolecular cyclization of cyanomethyl 2-alkoxy-N-buta-2,3-dienimidothioate (1-aza-1,3,4-triene).

Isomérisation thermique de vinyl-2 aziridines N-substituées

1976 ◽  
Vol 54 (10) ◽  
pp. 1590-1598 ◽  
Author(s):  
Daniel Borel ◽  
Yvonne Gelas-Mialhe ◽  
Roger Vessière
Keyword(s):  
Double Bond ◽  
Thermal Isomerization ◽  
Experimental Results ◽  
Phenyl Substituent ◽  
Ethylene Imine ◽  
Ring Carbon ◽  
Reaction Proceeds

The thermal isomerization of 2-vinylaziridines, variously substituted on the ring and the double bond, has been studied. The nature of the products formed depends on the nature of the substituents in positions 1 and 3. If the ring carbon-3 carries a phenyl substituent, the thermolysis yields, in most cases, a Δ-2-pyrroline. With unsubstituted or 3-alkylaziridines the reaction proceeds, depending on the nature of the substituent on the nitrogen, either to an ethylene imine or to a mixture of Δ-2- and Δ-3-pyrrolines. Mechanisms to interpret the experimental results are proposed. [Journal translation]

Synthesis of New Pyrazolenines and Cyclopropenyl Alcohols Directly from Propargyl Alcohols

2005 ◽  
Vol 2005 (5) ◽  
pp. 289-292 ◽  
Author(s):  
Naceur Hamdi ◽  
Pierre Henry Dixneuf ◽  
Youssef Arfaoui ◽  
Ezzeddine Haloui
Keyword(s):  
Double Bond ◽  
Good Yield ◽  
Dipolar Cycloaddition ◽  
Propargylic Alcohols ◽  
Propargyl Alcohols

The 1,3-dipolar cycloaddition of 2-diazopropane 1 to propargylic alcohols is regioselective and leads to 3H-pyrazoles 3 in good yield. The surprising formation of the tetrasubstitued pyrazolenine 4c from HC=CCH2OH and 1 can be explained via the 1,3-dipolar cycloadduct intermediate followed by a second cycloaddition of 1 to the C=C double bond and loss of dinitrogen. The photolysis of the antibacterial pyrazolenines 3 and 4 selectively gives α and β dimethylcyclopropenyl alcohols 5 and 6.

The photochemistry of aliphatic and alicyclic α,β-unsaturated nitro compounds. A study of double bond cleavage following intramolecular cyclization and nitro-nitrite rearrangement

1984 ◽  
Vol 37 (6) ◽  
pp. 1231 ◽  
Author(s):  
RD Grant ◽  
JT Pinhey
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Methyl Acrylate ◽  
Room Temperature ◽  
Bond Cleavage ◽  
Nitro Compounds ◽  
Significant Extent ◽  
Cleavage Reaction ◽  
Nitrile Oxides ◽  
Bond Cleavage Reaction

The light-induced intramolecular cyclization of α, β-unsaturated nitro compounds leading to double bond cleavage, which had previously been detected in a small number of β-nitrostyrenes and α-nitro-stilbenes, has been shown to occur in a range of aliphatic and alicyclic α, β -unsaturated nitro compounds. At room temperature the reaction competes to a significant extent with the well known nitro-nitrite rearrangement in the irradiation of 1-nitro-2-phenylcyclohexene (2), 1-methyl-2-nitro-cyclohexene (6), 1-methyl-2-nitrocycloheptene (11), 2-methyl-3-nitrobut-2-ene (23) and 2-nitro-3-phenylbut-2-ene (24), while it was the only reaction detected in the case of 1-methyl-2-nitrocyclo- octene (12) and 1-nitrocyclooctene (19). No evidence for the cleavage reaction was found with 1-methyl-2-nitrocyclopentene (10), 1-nitrocyclohexene (17), 1-nitrocycloheptene (18) and 3-nitropent-2-ene (25). The nitrile oxides produced in the double bond cleavage reaction were trapped in a cycloaddition with methyl acrylate, yielding 3-substituted methyl 4,5-dihydroisoxazole-5-carboxylates. Irradiations of 1-methyl-2-nitrocyclohexene (6) and 1-methyl-2-nitrocycloheptene (11) in refluxing benzene afforded only the bridged ring isoxazolines (30) and (31) respectively. Syntheses of a number of nitro-olefins are also reported.

Sign in / Sign up

Export Citation Format

Share Document