scholarly journals Huisgen [3 + 2] Dipolar Cycloadditions of Phthalazinium Ylides to Activated Symmetric and Non-Symmetric Alkynes

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4416
Author(s):  
Vasilichia Antoci ◽  
Costel Moldoveanu ◽  
Ramona Danac ◽  
Violeta Mangalagiu ◽  
Gheorghita Zbancioc
Keyword(s):  
Reaction Time ◽  
Comparative Study ◽  
Cycloaddition Reaction ◽  
Environmentally Friendly ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Dimethyl Acetylenedicarboxylate ◽  
Thermal Heating ◽  
Dipolar Cycloadditions ◽  
Methyl Propiolate

We present herein a straightforward and efficient pathway for the synthesis of pyrrolophthalazine cycloadducts via Huisgen [3 + 2] dipolar cycloaddition reactions of phthalazinium ylides to methyl propiolate or dimethyl acetylenedicarboxylate (DMAD). A thoroughly comparative study concerning the efficiency of synthesis, conventional thermal heating (TH) versus microwave (MW) and ultrasound (US) irradiation, has been performed. The cycloaddition reactions of phthalazinium ylides to methyl propiolate occur regiospecific, with a single regioisomer being obtained. Under conventional TH, the cycloaddition reaction of phthalazinium ylides with DMAD occurs to a mixture of inseparable partial and fully aromatized pyrrolophthalazine cycloadducts, while MW or US irradiation are leading only to fully aromatized compounds, with the reactions becoming selective. A feasible mechanism for formation of fully aromatized compounds is presented. Besides selectivity, it has to be noticed that the reaction setup under MW or US irradiation offer a number of other certain advantages: higher yields, decreasing of the amount of used solvent comparative with TH, decreasing of the reaction time from hours to minutes and decreasing of the consumed energy; consequently, these reactions could be considered environmentally friendly.

1,3-Dipolar Cycloadditions Involving Allenes: Synthesis of Five-Membered Rings

2020 ◽  
Vol 23 (27) ◽  
pp. 3064-3134 ◽  
Author(s):  
Ana L. Cardoso ◽  
Maria I.L. Soares
Keyword(s):  
Transition Metal ◽  
Cycloaddition Reaction ◽  
Building Blocks ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Relevant Research ◽  
Dipolar Cycloadditions ◽  
Recent Developments ◽  
Synthetic Equivalent ◽  
Metal Catalyzed

The 1,3-dipolar cycloaddition reaction is a powerful and versatile strategy for the synthesis of carbocyclic and heterocyclic five-membered rings. Herein, the most recent developments on the [3+2] cycloaddition reactions using allenes acting either as dipolarophiles or 1,3-dipole precursors, are highlighted. The recent contributions on the phosphine- and transition metal-catalyzed [3+2] annulations involving allenes as substrates are also covered, with the exception of those in which the formation of a 1,3-dipole (or synthetic equivalent) is not invoked. This review summarizes the most relevant research in which allenes are used as building blocks for the construction of structurally diverse five-membered rings via [3+2] annulation reactions.

1,3-Dipolar cycloadditions of ylide of 5-nitro-2-furfurylpyridinium bromide in indolizine synthesis

1982 ◽  
Vol 47 (6) ◽  
pp. 1738-1745 ◽  
Author(s):  
Jarmila Štetinová ◽  
Miloslava Dandárová ◽  
Jaroslav Kováč ◽  
Darina Mesárošová ◽  
Ján Leško
Keyword(s):  
Mass Spectra ◽  
Cycloaddition Reaction ◽  
Ethyl Acrylate ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate ◽  
Diethyl Maleate ◽  
Dipolar Cycloadditions ◽  
H Nmr

Substituted 3-(5-nitro-2-furyl)indolizines III-X were synthesized by 1,3-dipolar cycloaddition reaction of the ylide II, generated from 5-nitro-2-furfurylpyridinium bromide (I), with acrylonitrile, ethyl acrylate, diethyl maleate, benzalacetophenone, ethyl 3-(5-nitro-2-furyl)acrylate, (5-nitro-2-furfurylidene)acetophenone, β-nitrostyrene and dimethyl acetylenedicarboxylate. The structure of these products is discussed on the basis of their 1H NMR and mass spectra.

Syntheses of Anomeric Pairs of New C-Nucleosides via 1,3-Dipolar Cycloaddition Reaction, Part I

1997 ◽  
Vol 52 (11) ◽  
pp. 1383-1392 ◽  
Author(s):  
Zahida Maqbool ◽  
Mashooda Hasan ◽  
Kevin T. Pott ◽  
Abdul Malik ◽  
Tanveer Ahmad Nizami ◽  
...  
Keyword(s):  
Comparative Study ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Reasonable Degree

Abstract A convenient pathway to a variety of β-and α-C-nucleosides has been developed by utilizing 1,3-dipolar cycloaddition reactions of various exocyclic and endocyclic heterocyclic ylides with β (5a) and α (5b) anomers of ethyl 3-(2′,3′-O-isopropylidene-5′-O-trityl-D-ribofurano-syl) propiolate, respectively. Assignment of configuration at exposition of the C-nucleosides could be made by a comparative study of the properties of corresponding α and β anomers with a reasonable degree of certainity.

scholarly journals Utilization of 1-phenylimidazo[1,5-a]quinoline as partner in 1,4-dipolar cycloaddition reactions

2020 ◽  
Vol 75 (3) ◽  
pp. 259-267
Author(s):  
Areej M. Jaber ◽  
Jalal A. Zahra ◽  
Mustafa M. El-Abadelah ◽  
Salim S. Sabri ◽  
Monther A. Khanfar ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spectral Data ◽  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Dimethyl Acetylenedicarboxylate ◽  
X Ray ◽  
X Ray Crystallography

AbstractA Selected set of 2-(quinolin-2-yl)-1,3-oxazepino[7,6-b]indoles 4a–d and dihydroacenaphtho[1,2-f][1,3]oxazepine 5 have been prepared via 1,4-dipolar cycloaddition reaction involving 1-phenylimidazo[1,5-a]quinoline, dimethyl acetylenedicarboxylate, and N-(substituted)isatins or acenaphthoquinone. Structures of the new heterocycles 4a–d and 5 are supported by NMR and HRMS spectral data, and confirmed by single-crystal X-ray crystallography for 4c and 5.

Spiroheterocycles via Regioselective Cycloaddition Reactions of Nitrile Oxides with 5-Methylene-1H-pyrrol-2(5H)-ones

2010 ◽  
Vol 63 (3) ◽  
pp. 445 ◽  
Author(s):  
Nicola J. Beattie ◽  
Craig L. Francis ◽  
Andris J. Liepa ◽  
G. Paul Savage
Keyword(s):  
Cycloaddition Reaction ◽  
Biphasic System ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Nitrile Oxides ◽  
Facial Selectivity

Substituted 5-methylene-1H-pyrrol-2(5H)-ones underwent a 1,3-dipolar cycloaddition reaction with nitrile oxides to give the corresponding spiro heterocycles. Critical to this reaction was the development of a biphasic system for base-induced dehydrohalogenation of hydroximoyl chlorides, to give nitrile oxides, in the presence of a base-sensitive dipolarophile. A substituted N-tolyl 5-methylene-1H-pyrrol-2(5H)-one exhibited atropisomerism, which in turn led to a 4:1 facial selectivity during cycloaddition.

1,3-Dipolar Cycloaddition Reaction of Dimethyl Acetylenedicarboxylate with Hydrazones

Heterocycles ◽  
1974 ◽  
Vol 2 (2) ◽  
pp. 280 ◽  
Author(s):  
Haruo Ogura ◽  
Hiroshi Takahashi ◽  
Kazuo Kubo ◽  
Kozo Ogawa ◽  
Hitomi Sakai
Keyword(s):  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Dimethyl Acetylenedicarboxylate

scholarly journals Enantioselective 1,3-Dipolar Cycloaddition Reaction of Nitrones with α-(Acyloxy)acroleins Catalyzed by Dipeptide-Derived Chiral Tri- or Diammonium Salts

Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1835-1839 ◽  
Author(s):  
Chihiro Kidou ◽  
Haruki Mizoguchi ◽  
Tatsuo Nehira ◽  
Akira Sakakura
Keyword(s):  
Cycloaddition Reaction ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Reaction Conditions

Organoammonium salts of dipeptide-derived chiral triamines or diamines with TfOH catalyzed the enantioselective 1,3-dipolar cycloaddition reactions of α-acyloxyacroleins with nitrones to give the corresponding adducts in good yields (up to 96%) and with high diastereo- and enantioselectivities (up to 89% ee). Although α-(p-methoxybenzoyloxy)acrolein is rather unstable under the reaction conditions, α-(3-pyrroline-1-carbonyloxy)acrolein is stable enough to be smoothly converted into the corresponding adducts with the aid of the chiral organoammonium salt catalysts.

1,3-Dipolar Cycloadditions of a Chiral Oxazolidinone With Nitrones and Nitrile Oxides

1995 ◽  
Vol 48 (9) ◽  
pp. 1511 ◽  
Author(s):  
SG Pyne ◽  
J Safaei-G ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Hydrogen Atmosphere ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
The Novel ◽  
X Ray ◽  
Dipolar Cycloadditions ◽  
Nitrile Oxides ◽  
Exocyclic Methylene

The 1,3-dipolar cycloaddition reactions of the chiral oxazolidinone (1) and nitrones are highly regioselective and only 5,5-disubstituted isoxazolidine adducts are formed. These reactions occur under equilibrating conditions to give the more stable adducts that result from addition to the exocyclic methylene of (1) from the sterically more hindered π-face. The endo adducts are generally thermodynamically favoured. In one case the novel azetidine (21) was formed from the treatment of the adduct (4a) with palladium hydroxide on carbon under a hydrogen atmosphere. The major adducts from the reaction of (1) and nitrile oxides (16a,b) had the expected stereochemistry, addition of the 1,3-dipole having occurred from the less hindered π-face of the exocyclic methylene of (1). The stereochemistry of many of these products has been elucidated by single-crystal X-ray structural determinations.

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