Palladium-catalyzed approach to the synthesis of five-membered O-heterocycles

Palladium-Catalyzed Highly Stereoselective Dearomative [3 + 2] Cycloaddition of Nitrobenzofurans

“…Notably, 1i with an ester group and 1j with a nitro group were tolerated, indicating a broad scope of this reaction. Furthermore, benzofurans with substituent at the 6 or 7 position bearing groups with varied electronic properties (6-MeO, 6-Br, 6-Ph, 6-phenylethynyl, 7-MeO, 7-Me, 7-allyl) were converted successfully in good to excellent yields and selectivity ( Table 2, entries [11][12][13][14][15][16][17]. Alkene and alkyne were also integrated under these reaction conditions ( Table 2, entries 14 and 17).…”

“…Palladium-catalyzed formal [3 + 2] cycloaddition reaction [10][11][12] between electrondeficient alkenes and epoxybutenes 13 is a powerful and atom-economic tool for the synthesis of substituted tetrahydrofurans. [14][15][16][17][18][19][20][21] Unfortunately, control of the enantioselectivity and diastereoselectivity of this kind of reaction remains challenging because of the long distance between the reactive site and the chiral catalyst in the stereoselectivity-determining transition state. 22 Limited successful examples using specific substrates have been reported.…”

Rhodium Catalyzed Carbonylative Approaches for Heterocycles Synthesis

“…Considering the widespread applications of heterocyclic compounds, the development in the synthetic approach for nitrogen bearing heterocyclic compounds are most emerging area in the modern drug development (Figure 2) and discovery. [2][3][4][5][6][7][8][9][10] Meanwhile from numerous years, heterocycles having nitrogen are employed in medicinal compounds, and are the main scaffolds in various drugs like Captopril (hypertension), Vincristine (cancer chemotherapy) and Morphine (analgesic). [11][12][13][14][15][16][17][18] Past few decades, carbonylation reaction have emerged an important synthetic route for the synthesis of carbonyl compounds in organic chemistry.…”