| Title: |
Ethyl 2‐Cyano‐2‐(2‐nitrobenzenesulfonyloxyimino) Acetate (ortho‐NosylOXY)‐Mediated Double Beckmann Rearrangement of Ketoximes under Microwave Irradiation: A Mechanistic Perception |
| Authors: |
Dev, Dharm; Kalita, Tapasi; Mondal, Tanmay; Mandal, Bhubaneswar |
| Source: |
Advanced Synthesis & Catalysis ; volume 363, issue 5, page 1427-1435 ; ISSN 1615-4150 1615-4169 |
| Publisher Information: |
Wiley |
| Publication Year: |
2020 |
| Collection: |
Wiley Online Library (Open Access Articles via Crossref) |
| Description: |
A method for Beckmann rearrangement using ethyl 2‐cyano‐2‐(2‐nitrobenzenesulfonyloxyimino) acetate ( o ‐NosylOXY) under microwave irradiation is reported. Ketoximes (19 examples) are converted to the corresponding amides/lactams with 69–97% yields in ∼10 minutes without any Lewis acid or co‐catalyst. This is an example of halogen‐free organocatalytic Beckmann rearrangement. Nuclear magnetic resonance (NMR)‐ and high‐resolution mass spectrometry (HRMS)‐based detailed mechanistic investigation suggest that o ‐NosylOXY acts as an initiator. Such initiators are reported before based on density functional theory (DFT) calculations. However, we report here the HRMS signatures of two transient intermediates, the nitrilium ion and the nitrilium ion's dimeric species. Rigorous NMR‐based investigation of the reaction mechanism is performed. Our results indicate that the reported Beckmann rearrangement proceeds via two consecutive rearrangements. magnified image |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1002/adsc.202001416 |
| Availability: |
https://doi.org/10.1002/adsc.202001416; https://onlinelibrary.wiley.com/doi/pdf/10.1002/adsc.202001416; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/adsc.202001416 |
| Rights: |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
| Accession Number: |
edsbas.52711415 |
| Database: |
BASE |