Microwave assisted organic synthesis-a review

In 1893, P. Biginelli reported the synthesis of functionalized 3, 4-dihydropyrimidin-2(1H)-ones (DHPMs) via three-component condensation reaction of an aromatic aldehyde, urea, and ethyl acetoacetate. In the past decade, this long-neglected multicomponent reaction has experienced a remarkable revival, mainly due to the interesting pharmacological properties associated with this dihydropyrimidine scaffold. In this Account, we highlight recent developments in the Biginelli reaction in areas such as solid-phase synthesis, combinatorial chemistry, and natural product synthesis.

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Recent advances in the Biginelli dihydropyrimidine synthesis. New tricks from an old dog.

New types of Lewis acids as water-compatible catalysts have been developed. Various metal salts were found to work as Lewis acid catalysts in aqueous media, and catalytic asymmetric aldol reactions in such media have been attained. Furthermore, Lewis acid-surfactant combined catalysts, which can be used for reactions in water without using any organic cosolvents, have been also developed. These investigations will contribute to reducing the use of harmful organic solvents and to develop efficient catalytic systems which cannot be realized in conventional organic solvents.

Development of novel Lewis acid catalysts for selective organic reactions in aqueous media.

6.1. Oxadiazoles 4154 6.2. Diazaphospholes 4154 7. Six-Membered Heterocycles with One Heteroatom 4155 7.1. Pyridines 4155 7.2. Pyridinones 4155 7.3. Quinolines 4156 7.4. Quinolinones 4157 7.5. Isoquinolines 4157 7.6. Acridines 4158 7.7. Pyranones 4158 7.8. Flavones 4159 8. Six-Membered Heterocycles with Two Heteroatoms 4159 8.1. Pyridazinones 4159 8.2. Pyrimidines 4159 8.3. Pyrimidinones 4160 8.4. Quinazolines 4162 8.5. Quinazolinones 4162 8.6. Quinoxalines 4164 8.7. Quinoxalinediones 4165 8.8. Oxazines 4165 8.9. Oxazinones 4166 8.10. Thiazines 4166 9. Six-Membered Heterocycles with Three Heteroatoms 4166

Solvent-free heterocyclic synthesis.

Recent Advances in the Friedländer Reaction

Indium(III) chloride-catalyzed one-pot synthesis of dihydropyrimidinones by a three-component coupling of 1,3-dicarbonyl compounds, aldehydes, and urea: an improved procedure for the Biginelli reaction.

General Procedure for the Synthesis of α-Amino Phosphonates from Aldehydes and Ketones Using Indium(III) Chloride as a Catalyst

A simple and efficient procedure for the rearrangement of substituted epoxides catalyzed by InCl3 has been developed. Aryl-substituted epoxides isomerize with complete regioselectivity to form a single carbonyl compound via cleavage of the benzylic C−O bond. The reactions are simple, fast, and high yielding. This procedure is very mild compared to those catalyzed with BF3 and other Lewis acids and compatible with several acid-sensitive functionalities. This protocol provides a highly selective synthesis of substituted benzylic aldehydes and ketones. However, rearrangement of alkyl-substituted epoxides is not very selective.

https://chemistry.mdma.ch/hiveboard/rhodium/pdf/indium.epoxide-rearr.pdf

Indium(III) Chloride-Promoted Rearrangement of Epoxides: A Selective Synthesis of Substituted Benzylic Aldehydes and Ketones

Microwave-assisted simple synthesis of quinolines from anilines and alkyl vinyl ketones on the surface of silica gel in the presence of indium(III) chloride

Umasish Jana

Papers

Indium(III) chloride-catalyzed one-pot synthesis of dihydropyrimidinones by a three-component coupling of 1,3-dicarbonyl compounds, aldehydes, and urea: an improved procedure for the Biginelli reaction.

General Procedure for the Synthesis of α-Amino Phosphonates from Aldehydes and Ketones Using Indium(III) Chloride as a Catalyst

Indium(III) Chloride-Promoted Rearrangement of Epoxides: A Selective Synthesis of Substituted Benzylic Aldehydes and Ketones

Microwave-assisted simple synthesis of quinolines from anilines and alkyl vinyl ketones on the surface of silica gel in the presence of indium(III) chloride

Efficient microwave-assisted synthesis of quinolines and dihydroquinolines under solvent-free conditions