Org Lett
August 2024
The regio-/stereoselective synthesis of vinyl cyclobutanols from alkynyl cyclobutanols is demonstrated. Here, selective C-C bond activation of the cyclopropyl alcohol ring has been achieved in the presence of the cyclobutanol ring. The KIE experiments indicated the noninvolvement of the O-H oxidative addition step in the rate-determining step.
View Article and Find Full Text PDFSelective functionalization of the indole-C3-C bond with aromatic/heteroaromatic 1,2-diketones has been uncovered for the first time. Cobalt catalyst was found to be an effective catalyst for this unusual transformation. This -C-C bond functionalization occurred in the presence of easily available weakly coordinating groups such as ketone and ester.
View Article and Find Full Text PDFHerein, we have demonstrated a rhodium-catalyzed carboamination of olefin with the double bond intact. For the first time, deacylative carboamination of the maleimide has been achieved wherein phenoxyacetamide has behaved as the aminating source. In addition to carboamination, we have also disclosed the C-H olefination protocol where the maleimide group has been installed successfully in the -position of phenoxyacetamide.
View Article and Find Full Text PDFHerein, we report the annulation of indole-2-carboxamides with bicycloalkenes, to synthesize β-carboline-1-one derivatives under mild conditions. The commercially available ruthenium catalyst was used for the reaction. This reaction tolerates a wide range of functional groups and affords a good yield of β-carboline-1-one derivatives.
View Article and Find Full Text PDFWe report here a Rh(III) catalyzed regio- and stereoselective synthesis of alkynylated and bis-isocoumarin from 1,3-dialkyne. Exclusive one-pot formation of 3,3-bis-isocoumarin isomers has been achieved by eliminating several other possibilities. This is the first example of transition metal catalyzed synthesis of alkynylated and bis-isocoumarin scaffolds.
View Article and Find Full Text PDFWe report herein a cobalt-catalyzed 8-aminoquinoline-directed highly regio- and stereoselective C-H/N-H activation annulation of indole-2-carboxamides with 1,2-dihydronaphthalene for the synthesis of β-carboline-1-one derivatives at room temperature. A cheaper and commercially available cobalt catalyst has been used for this transformation. The protocol tolerates a wide range of functionalities, affording β-carboline-1-one derivatives in good yields.
View Article and Find Full Text PDFThe ruthenium(II)-catalyzed regioselective annulation of -(7-azaindole)amides with 1,3-diynes has been demonstrated. Bioactive -amino-7-azaindole has been used as a new bidentate directing group to furnish an array of 3-alkynylated isoquinolones. Furthermore, the developed protocol works efficiently for both aryl- and heteroaryl-substituted amides producing a range of pharmacologically useful 7-azaindole-based isoquinolones with a wide range of functionality.
View Article and Find Full Text PDFA redox neutral Co(III)-catalyzed annulation of α,β-unsaturated oxime ether with alkyne has been reported. Multisubstituted pyridines were synthesized in good yields without the use of any heavy metal oxidants. The developed methodology tolerates a variety of functional groups.
View Article and Find Full Text PDFA highly stereo- and regioselective synthesis of the core skeleton of hexahydrobenzo[]phenanthridine-type alkaloids is reported herein for the first time. A wide range of substrate scope, excellent functional group tolerance, and good to excellent yields were observed. This protocol gives very concise and efficient access to the core skeleton of chelidonine alkaloids as compared to the earlier approaches.
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