Micelle-driven organic synthesis: an update on the synthesis of heterocycles and natural products in aqueous medium over the last decade

Abstract

Organic synthesis guided by micellar nanoreactors constitutes one of the fundamental fields of organic chemistry that is expected to furnish chemical synthesis in a sustainable fashion. Due to its promise, we were also attracted to using the micelles to enhance chemical reactivity and selectivity and to explore their newer applications in natural products and heterocyclic chemistry. As on date, there is no comprehensive review article that highlights the repertoire of chemical reactions developed in micelles furnishing a range heterocycles and natural products/scaffolds, barring the metal-catalyzed cross-coupling reactions. In this review, we document the last decade (2014-2024) progress of organic reactions developed in micelles to yield a range of heterocyclic and natural product-based scaffolds. Notably, we have excluded the content related to metal-catalyzed cross-coupling reactions and some other aspects of micelles due to the number of overlapping reviews written on such topics. In the current article, we briefly introduce micellar catalysis, regions of reaction sites in micelles, and various surfactants utilized in micelle chemistry. Our discussion also captures the importance of micellar catalysis compared to the conventional organic synthesis. More importantly, the focus of our review is largely on the collection of chemical transformations accomplished in the last decade in accessing heterocycles and natural products to showcase the advancement of organic synthesis through sustainable fashion. Wherever required, we have also captured the various interactions of surfactants with the substrates necessary for driving the reactions and discussed the importance of these heterocycles/natural products in intercepting the key biological pathways.

Fig. 1. Structure of normal spherical micelle and its various regions.

Fig. 2. Structure of various types of commercial, designer and bio-surfactants.

Fig. 3. Diagrammatic representation of reactions in aqueous micelles and in conventional organic solvents.

Scheme 1. Synthesis of benzo[a]phenazine and naphtho[2,3-d]imidazoles in aqueous SDS-micellar medium.

Scheme 2. Synthesis of mesoionic thiazolo[2,3-a]isoquinolinium compounds in CTAB-micellar medium.

Scheme 3. A three component synthesis of chromeno[2,3-b]quinolinediones in aqueous TBAB micellar medium.

Scheme 4. A three component synthesis of 7-aryl-benzopyrano[4,3-b]benzopyran-6,8-diones in SDS-micellar medium.

Scheme 5. A four component synthesis of 2-amino-6-(1H-indol-3-yl)-4-arylpyridine-3,5-dicarbonitriles in aqueous CTAB micellar medium.

Scheme 6. Ag-catalyzed synthesis of furans/pyroles in aqueous TPGS-750 micellar medium.

Scheme 7. Synthesis of [1,2,3]-triazolyl-thiazolidinones in aqueous CTAB micellar medium.

Scheme 8. Synthesis of [dihydropyrano[2,3-c]pyrazoles] in aqueous CAPB micellar medium.

Scheme 9. A three component synthesis of dihydropyrrolo[1,2-a]quinolines in aqueous CTAB micellar medium.

Scheme 10. A three component synthesis of 11-(chromen-3-yl)-8,8-dimethyl-8,9-dihydro-6H-chromeno[2,3-b]quinoline-10,12(7H,11H)-dione SDS micellar medium.

Scheme 11. A selective strain-promoted azide–alkyne cycloaddition in aqueous micellar medium.

Scheme 12. (a) A nano-ZnO catalyzed synthesis of 5-phenylbenzopyrimido[4,5-b]quinolones in aqueous CTAB micellar medium; (b) a multicomponent synthesis of 8-substituted pyrido[2,3-d]pyrimidine-6-carbonitriles using aqueous PEG-DBU.

Scheme 13. NaH-mediated synthesis of 4-phenylsulfonamido-6-aryl-2-phenylpyrimidine-5-carbonitriles in aqueous micellar medium.

Scheme 14. Cu-catalyzed synthesis of quinazolinones in aqueous TPGS-750-M micellar medium.

Scheme 15. Fe(iii)-catalyzed synthesis of, 5-dispirosubstituted piperidines in aqueous SDS-micellar medium.

Scheme 16. PTSA-mediated (E)-6-phenyl-7-styryl-5,6-dihydro-dibenzo[b,h][1,6]naphthyridines in aqueous SDS-micellar medium.

Scheme 17. 2-PP-mediated synthesis of 3-ethylcarboxylate- and 3-acety coumarin in aqueous SDS-micellar medium.

Scheme 18. A divergent synthesis of pyroles and indoles in aqueous CTAC-micellar medium and DCE respectively.

Scheme 19. Synthesis of quinolines in aqueous CTOH-micellar medium.

Scheme 20. Synthesis of spiro[dihydroquinoline-naphthofuranone] in aqueous SDS micellar medium.

Scheme 21. Synthesis of naphtha[1,3]oxazines in aqueous SDS micellar medium.

Scheme 22. Cu-catalyzed synthesis of imidazole[1,2-a]pyridine in aqueous SDS micellar medium.

Scheme 23. MGSFe-catalyzed synthesis of pyrroles in micelles.

Scheme 24. Reverse ZnO-nanomicelle catalyzed synthesis of 2,3-dihydroquinazolin-4(1H)-ones micellar medium.

Scheme 25. (a) Synthesis of 2-(indol-3-yl)benzothiazoles and (b) 4H-pyrimido [2,1-b]benzothiazoles in micellar medium.

Scheme 26. Synthesis of chromenoquinoline via the Povarov reaction C in aqueous PyNAG-micellar medium.

Scheme 27. Synthesis of quinoxaline, 1,4-benzoxazine and 1,4-benzothiazine scaffolds in CPB-micellar medium.

Scheme 28. Regioselective synthesis of cannabenoids in “on water” and “in water” chemistry using SDS micelles.

Scheme 29. Photo-Fries rearrangement of 2-acetyl and 2-benzoyl estrones in aqueous micellar medium.

Scheme 30. (a) Construction of 2,8-dioxabicyclo[3.3.1]nona-3,6-dienes and (b) oxabicyclo[n.3.1]alkene frameworks in aqueous micellar medium.