Unprecedented access to functionalized pyrrolo[2,1-a]isoquinolines from the domino reaction of isoquinolinium ylides and electrophilic benzannulated heterocycles

2021 ◽  
Author(s):  
Sheba Ann Babu ◽  
Rajalekshmi A. R. ◽  
Nitha P. R. ◽  
Vishnu K. Omanakuttan ◽  
Rahul P. ◽  
...  
Keyword(s):  
Ring Opening ◽  
Domino Reaction ◽  
Dipolar Cycloaddition

The reaction between electrophilic benzannulated heterocycles and isoquinolinium methylides results in a domino dipolar cycloaddition-ring opening transformation, generating functionalized pyrrolo[2,1-a]isoquinolines and S–S-bridged bis-pyrrolo[2,1-a]isoquinolines.

scholarly journals Microwave-assisted three-component domino reaction: Synthesis of indolodiazepinotriazoles

2013 ◽  
Vol 9 ◽  
pp. 401-405 ◽  
Author(s):  
Rajesh K Arigela ◽  
Sudhir K Sharma ◽  
Brijesh Kumar ◽  
Bijoy Kundu
Keyword(s):  
Sodium Azide ◽  
Ring Opening ◽  
Domino Reaction ◽  
Dipolar Cycloaddition ◽  
Reaction Synthesis ◽  
Microwave Assisted ◽  
Internal Alkyne

A microwave-assisted three-component protocol involving N-1 alkylation of 2-alkynylindoles with epichlorohydrin, ring opening of the epoxide with sodium azide, and an intramolecular Huisgen azide–internal alkyne 1,3-dipolar cycloaddition domino sequence has been described. The efficacy of the methodology has been demonstrated by treating various 2-alkynylindoles (aromatic/aliphatic) with epichlorohydrin and sodium azide furnishing annulated tetracyclic indolodiazepinotriazoles in satisfactory yields.

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.

scholarly journals Intramolecular N–Me and N–H aminoetherification for the synthesis of N-unprotected 3-amino-O-heterocycles

2021 ◽  
Author(s):  
Mahesh P. Paudyal ◽  
Mingliang Wang ◽  
Juha H. Siitonen ◽  
Yimin Hu ◽  
Muhammed Yousufuddin ◽  
...  
Keyword(s):  
Ring Opening ◽  
Domino Reaction ◽  
Aziridine Ring

A mild Rh-catalyzed method for synthesis of cyclic unprotected N–Me and N–H 2,3-aminoethers using an olefin aziridination–aziridine ring-opening domino reaction has been developed.

Benzonaphthyridine N-Oxides as 1,3-Dipoles

1996 ◽  
Vol 49 (4) ◽  
pp. 523 ◽  
Author(s):  
T Zujewska ◽  
B Bachowska
Keyword(s):  
Ring Opening ◽  
Room Temperature ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate ◽  
Ring Contraction

Benzonaphthyridine N-oxides give N-ylides with dimethyl acetylenedicarboxylate at room temperature, most probably by 1,3-dipolar cycloaddition followed by ring contraction to form an aziridine derivative, and ring opening.

scholarly journals Synthesis of Octahydropyrano[2,3-d]Pyrimidine Derivatives via Tetrahydropyrano[3,2-e][1,3]Thiazolo[3,2-a]Pyrimidine and 2,6-Dichlorobenzonitrile Oxide

2018 ◽  
Vol 42 (6) ◽  
pp. 317-319
Author(s):  
Qing Zeng ◽  
Demin Ren ◽  
Aiting Zheng ◽  
Xiaofang Li
Keyword(s):  
Ring Opening ◽  
Crystallographic Analysis ◽  
Dipolar Cycloaddition ◽  
Pyrimidine Derivatives ◽  
X Ray ◽  
Moderate Yield

N1-substituted octahydro-1 H-pyrano[2,3- d]pyrimidines derivatives were prepared in moderate yield by the reaction of methyl [(4a RS,5 SR,10a RS)-5-aryl-2-oxo-3,4,4 a,10 a-tetrahydro-2 H,5 H-pyrano[3,2- e][1,3]thiazolo[3,2- a]pyrimidin-8(9 H)-ylidene]acetate and 2,6-dichorobenzonitrile oxide via a domino 1,3-dipolar cycloaddition/ring-opening/dethionation process. The structures of the products were characterised by spectroscopic and X-ray crystallographic analysis.

Recent Advances in the Chemistry of Doubly Activated Cyclopropanes: Synthesis and Reactivity

2019 ◽  
Vol 23 (3) ◽  
pp. 276-312 ◽  
Author(s):  
Purushothaman Gopinath ◽  
Srinivasan Chandrasekaran
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Electron Donor ◽  
Ring Opening ◽  
Dipolar Cycloaddition ◽  
Recent Advances ◽  
Donor Acceptor ◽  
Synthesis Reactions ◽  
Donor Substituent ◽  
Electron Donor Substituent

Diactivated cyclopropanes containing two geminal electron withdrawing groups, commonly called as ‘Doubly Activated Cyclopropanes’ are useful synthons for the synthesis of many interesting natural products and functionalized molecules. These geminal electron withdrawing groups (EWG’s) facilitate the regioselective ring opening of cyclopropanes by polarizing the C-C bond adjacent to it. This polarization also allows them to undergo 1,3 dipolar cycloaddition reactions when substituted with a suitable electron donor substituent at the adjacent carbon (donor-acceptor cyclopropanes) in the presence of suitable dipolarophiles. In this review, we discuss the recent advances in the chemistry of doubly activated cyclopropanes: their synthesis, reactions and applications in total synthesis.

Darstellung enantiomerenreiner 3-Oxa-2,7-diazabicyclo[3.3.0]octane und ihre Umwandlung in andere bicyclische Ringsysteme/Preparation of Pure Enantiomeric 3-Oxa-2,7-diazabicyclo[3.3.0]octanes and their Conversion to Other Bicyclic Ring-Systems

1999 ◽  
Vol 54 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Hans Günter Aurich ◽  
Michael Soeberdt
Keyword(s):  
Sodium Hydroxide ◽  
Ring Opening ◽  
Dipolar Cycloaddition ◽  
Ring Systems ◽  
Swern Oxidation

Pure Enantiomeric (S)-N-benzylalaninol (R1 = Me) and (S)-N-benzylvalinol (R1 = i-Pr) were allylated with Br-CH2-CH=CR2R3 (R2 = R3 = H; R2 = Ph, R3 = H; R2 = R3 = Ph). Swern oxidation followed by treatment with methylhydroxylamine afforded nitrones 6 (Me- N(O)=CH-CHR1-N(CH2Ph)CH2-CH=CR2R3) which underwent an intramolecular 1,3-dipolar cycloaddition providing 3-oxa-2,7-diazabicyclo[3.3.0]octanes, e.g. (1R,5R,8S)-7-benzyl-2,8- dimethyl-3-oxa-2,7-diazabicyclo[3.3.0]octane 7a (R1 = Me, R2 = R3 = H) and (1R,4R,5R,8S)- 7-benzyl-2,8-dimethyl-4-phenyl-3-oxa-2,7-diazabicyclo[3.3.0]-octane 7b (R1 = Me, R2 = Ph, R3 = H).Reductive ring opening of 7a and 7b afforded the corresponding a-hydroxyalkylated pyrrolidines (9a: R2 = H or 9b: R2 = Ph. resp.). Condensation of these compounds with benzaldehyde yielded a mixture of diastereomeric 4-oxa-2,8-diazabicyclo[4.3.0]- nonanes: 10a/11a (1R,3S,6R,9S)/(1R,3R,6R,9S) R1 = Me, R2 = R3 = H and 10b /lib (1R,3S,5R,6R,9S)/(1R,3R,5R,6R,9S) R1 = Me, R2 = Ph, R3 = H. Pyrrolidine 9b was converted to the mesylate which formed (1R,4S,5R,7S)-3-benzyl-4,6-dimethyl-7-phenyl-3,6-diazabicyclo[3.2.0]heptane 13 along with (4R,5S)-1-benzyl-3,5-dimethyl-4-styryl-imidazolidine 15 upon treatment with sodium hydroxide.

scholarly journals Synthesis of highly functionalized β-aminocyclopentanecarboxylate stereoisomers by reductive ring opening reaction of isoxazolines

2012 ◽  
Vol 8 ◽  
pp. 100-106 ◽  
Author(s):  
Melinda Nonn ◽  
Loránd Kiss ◽  
Reijo Sillanpää ◽  
Ferenc Fülöp
Keyword(s):  
Ring Opening ◽  
Simple Procedure ◽  
Amino Alcohols ◽  
Dipolar Cycloaddition ◽  
Nitrile Oxides ◽  
Amino Esters ◽  
Ring Opening Reaction

A rapid and simple procedure was devised for the synthesis of multifunctionalized cyclic β-amino esters and γ-amino alcohols via the 1,3-dipolar cycloaddition of nitrile oxides to β-aminocyclopentenecarboxylates. The opening of the isoxazoline reductive ring to the corresponding highly functionalized 2-aminocyclopentanecarboxylates occurred stereoselectively with good yields.

ChemInform Abstract: Synthesis of Pyrrolo[1,3]diazepines by a Dipolar Cycloaddition-retro-Mannich Domino Reaction.

ChemInform ◽  
2010 ◽  
Vol 41 (12) ◽  
Author(s):  
Mary Liang ◽  
Cecilia Saiz ◽  
Chiara Pizzo ◽  
Peter Wipf
Keyword(s):  
Domino Reaction ◽  
Dipolar Cycloaddition
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