Abstract
This account provides a summary of a chapter on Microwave Irradiation for Accelerating Organic Reactions in Advances in Heterocyclic Chemistry, volume 90, Part II: Six, Sevenmembered, Spiro and Fused Heterocycles by E. S. H. El Ashry, A. A. Kassem and E. Ramadan. Microwave irradiation (MWI) has been used extensively in organic synthesis. Application of MWI leads to many advantages, like the use of non-corrosive and inexpensive reagents, in addition to the eco-friendly green chemistry economical and environmental impacts.
Highlights
This part includes heterocycles with one oxygen, sulfur or nitrogen as heteroatoms
Hetero DielsAlder reactions of glyoxylates with pentadienes were accelerated under Microwave irradiation (MWI) to afford a mixture of cis and trans pyrans; degradation as well as polymerization were avoided[3]
Intramolecular Diels-Alder cycloadditions were used for the synthesis of 1-3
Summary
This part includes heterocycles with one oxygen, sulfur or nitrogen as heteroatoms. Hetero DielsAlder reactions of glyoxylates with pentadienes were accelerated under MWI to afford a mixture of cis and trans pyrans; degradation as well as polymerization were avoided[3]. Intramolecular Diels-Alder cycloadditions were used for the synthesis of 1-3. The corresponding chromanones 9 have been obtained by the reaction of 3-hydroxy phenolic derivatives with N-cinnamoylazoles[10]. Diels-Alder reaction of (E)- and (Z)-3-styrylchromones with N-methyl and N-phenyl maleimide afforded the respective exo- and endo-cycloadducts stereoselectivly. Reaction of arylidenemalononitriles with α-methylene ketones gave 2-amino-3-cyanopyridines[14 10]. Reaction of N,N-dimethylformamide dimethyl acetal with 2,6-diacetylpyridine gave 2,6bis(3-dimethylamino-1-oxoprop-2-enyl)pyridine[17]. Cycloaddition between electron rich 6-[(dimethylamino)methylene]amino-1,3-dimethyl uracil and various electron deficient substrates gave pyrido[2,3-d]pyrimidine derivatives in a high regiospecific manner. Pyrazolo[3,4-b]pyridines, the 7-chloro-6-fluoro-2,4-dimethylquinoline and its mercaptothiadiazolyl or oxadiazolyl quinolines 21 were prepared via Diels-Alder reaction conversion of methyl 2-(3-oxo-3-phenylpropenylamino)benzoate into 3-benzoyl-1H-quinolin-4-one 2226,27. Reaction of arylidenemalononitriles with cyclic ketones gave 2-amino-3-cyanopyridines[14 26]. Nucleophilic substitution of 4bromoisoquinoline gave the corresponding 4-substituted isoquinolines. o-Bromobenzaldehyde was reacted with allylamine and homophthalic anhydride to afford 3111
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
