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A highly enantio- and diastereoselective method for the synthesis of functionalized chroman-2-ones and chromanes was achieved by using an organocatalytic domino Michael/hemiacetalization reaction of aliphatic aldehydes and ( E )-2-(2-nitrovinyl)phenols followed by a PCC oxidation and dehydroxylation, respectively. Using the modularly designed organocatalysts (MDOs) self-assembled from cinchona alkaloid derivatives and amino acids in the reaction media, the title products were obtained in good to high yields (up to 97%) and excellent diastereoselectivities (up to 99 : 1 dr) and enantioselectivities (up to 99% ee).
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Synthesis of Dihydropyrazoles via Palladium‐Catalyzed Cascade Heterocyclization/Carbonylation/Arylation of β,γ‐Unsaturated N ‐Tosyl Hydrazones
Abstract A Pd‐catalyzed heterocyclization/carbonylation/arylation cascade reaction between β,γ‐unsaturated N−Ts hydrazones and commercially available arylboronic acids as coupling partners is described, producing 2‐pyrazoline‐ketone derivatives in 11–78% yield. A detailed statistical analysis of reactivity patterns of boronic acids provided key information about the limitations of the method, highlighting the challenges of degradation pathways. Our methodology offers a tool for synthesizing diverse 2‐pyrazoline‐ketone derivatives, expanding the toolbox of accessible N−N‐heterocycles.
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- Award ID(s):
- 2154502
- PAR ID:
- 10482246
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Synthesis & Catalysis
- Volume:
- 366
- Issue:
- 5
- ISSN:
- 1615-4150
- Format(s):
- Medium: X Size: p. 1120-1127
- Size(s):
- p. 1120-1127
- Sponsoring Org:
- National Science Foundation
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