An experimental and theoretical study on the regioselective synthesis of a new class of spiropyrrolothiazoles with quinoxaline motifs via a 1,3-dipolar cycloaddition reaction. An evaluation of DFT methods

RSC Advances ◽  
2015 ◽  
Vol 5 (93) ◽  
pp. 76368-76376 ◽  
Author(s):  
Mahshid Hamzehloueian ◽  
Yaghoub Sarrafi ◽  
Zahra Aghaei
Keyword(s):  
Theoretical Study ◽  
Cycloaddition Reaction ◽  
Regioselective Synthesis ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Dft Methods ◽  
Π Interactions ◽  
New Class

Evaluation of B3LYP/6-31G(d,p), wB97xD/6-31G(d,p) and M06-2X/6-31G(d,p) methods revealed the importance of π/π interactions in regio- and stereoselectivity of cycloaddition reactions.

Regioselective Synthesis of Novel 4,4′-and 5,5′-bi-(1,2,4-triazole) Derivatives

2007 ◽  
Vol 2007 (8) ◽  
pp. 472-474 ◽  
Author(s):  
Ahmad M. Farag ◽  
Kamal M. Dawood ◽  
Nabila A. Khedr
Keyword(s):  
Regioselective Synthesis ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Triazole Derivatives

A regioselective synthesis is reported of a series of polysubstituted 1,2,4-triazoles and 4,4′- and 5,5′-bi-(1,2,4-triazoles) via 1,3-dipolar cycloaddition reactions of nitrilimines with some aza- and diaza-butadiene derivatives.

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.

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.

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.

Facile Regioselective Synthesis of 1,2,6,8-Tetraazaspiro[4.4]nona-2,6-dien-9-ones

2000 ◽  
Vol 55 (2) ◽  
pp. 222-226 ◽  
Author(s):  
Adel S. Girgis
Keyword(s):  
Cycloaddition Reaction ◽  
Regioselective Synthesis ◽  
Dipolar Cycloaddition

1,3-Dipolar cycloaddition reaction of nitrilimines to a variety of 3-aryl-5-arylmethylidene- 3,5-dihydro-2-phenyl-4H-imidazol-4-ones (3) afforded the corresponding 1,3,4,7,8-pentaaryl -1,2,6,8-tetraazaspiro[4.4]-nona-2,6-dien-9-ones (4) and not the regio-isomers 2,3,6,8,9-pentaaryl- 1,3,7,8-tetraazaspiro[4.4]nona-1,6-dien-4-ones (5) in high regioselectivity.

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