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The nitrogen-interrupted Nazarov cyclization can be a powerful method for the stereocontrolled synthesis of sp 3 -rich N -heterocycles. However, due to the incompatibility between the basicity of nitrogen and the acidic reaction conditions, examples of this type of Nazarov cyclization are scarce. Herein, we report a one-pot nitrogen-interrupted halo -Prins/ halo -Nazarov coupling cascade that joins two simple building blocks, an enyne and a carbonyl partner, to furnish functionalized cyclopenta[ b ]indolines with up to four contiguous stereocenters. For the first time, we provide a general method for the alkynyl halo -Prins reaction of ketones, thus enabling the formation of quaternary stereocenters. Additionally, we describe the outcomes of secondary alcohol enyne couplings, which exhibit helical chirality transfer. Furthermore, we investigate the impact of aniline enyne substituents on the reaction and evaluate the tolerance of different functional groups. Finally, we discuss the reaction mechanism and demonstrate various transformations of the prepared indoline scaffolds, highlighting their applicability in drug discovery campaigns.
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Exploring Interrupted Nazarov Cyclizations Using Tethered Sulfonamide Nucleophiles: Insights into Capture Pathways
Abstract This manuscript describes a study of diverse reaction outcomes that stem from the ionization ofaza‐alkynyl‐Prins adducts. Experimental results have demonstrated unexpected behavior in the nitrogen‐containing systems compared to the analogous oxygen derivatives derived fromoxa‐Prins/halo‐Nazarov sequences. In‐depth experimental studies and computational analysis revealed an intricate mechanism involving competinghalo‐Nazarov andimino‐Nazarov pathways. These findings further elucidate the reaction chemistry of 3‐halo‐pentadienyl cation intermediates, and expand their utility in synthetic transformations.
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- PAR ID:
- 10643013
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- European Journal of Organic Chemistry
- Volume:
- 27
- Issue:
- 43
- ISSN:
- 1434-193X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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