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

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.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:25

Enthalten in:

Molecules (Basel, Switzerland) - 25(2020), 19 vom: 25. Sept.

Sprache:

Englisch

Beteiligte Personen:

Antoci, Vasilichia [VerfasserIn]
Moldoveanu, Costel [VerfasserIn]
Danac, Ramona [VerfasserIn]
Mangalagiu, Violeta [VerfasserIn]
Zbancioc, Gheorghita [VerfasserIn]

Links:

Volltext

Themen:

7HZA2PL15F
Acetylenedicarboxylic acid dimethyl ester
Alkynes
Environmentally friendly
Huisgen [3 + 2] dipolar cycloaddition
Journal Article
Microwave
Phthalazines
Pyrrolophthalazine
Regiochemistry
Selectivity
Ultrasound
Ylides

Anmerkungen:

Date Completed 18.03.2021

Date Revised 18.03.2021

published: Electronic

Citation Status MEDLINE

doi:

10.3390/molecules25194416

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM315635398