Abstract
Abstract: The reaction of racemic 2-amino-4H-pyrans, such as 3-amino-1-aryl-1H-benzo[f]chromene-2-carbonitriles, with N-bromosuccinimide (NBS), in CH2 Cl2, at room temperature, is a very quick, regio, stereoselective, and high yielding process, affording major racemic (1S,2S)-2-bromo-3-imino-benzo[f]chromene or racemic (1S,2S)-2-bromo-3-(bromoimino)-benzo[f]chromene derivatives, when using 1.0 or 2.2 equivalents of NBS, respectively. This reaction, extended to isomeric 2-amino-4-aryl-4H-benzo[h]chromene-3-carbonitriles, showed an unexpected reactivity, affording racemic (3S,4S)-3-bromo-2-(bromoimino)-benzo[h]chromene-3-carbonitriles or 2-oxo-2H-benzo[h]chromene-3-carbonitriles, when using 2.2 or 1.0 equivalents of NBS, respectively. The reaction of alkyl 6-amino-5-cyano-2-methyl-4H-pyran-3-carboxylates has yielded unstable racemic (3S,4S)-alkyl 3-bromo-2-(bromoimino)-3-cyano-6-methyl-3,4-dihydro-2H-pyran-5-carboxylates. The mechanism of these reactions has been investigated by computational methods.
Original language | English |
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Pages (from-to) | 103-122 |
Number of pages | 20 |
Journal | Molecular Diversity |
Volume | 19 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 23 2015 |
Externally published | Yes |
Keywords
- 2-Amino-4H-pyrans
- DFT
- N-Bromosuccinimide
- NBS
- Reaction mechanism
ASJC Scopus subject areas
- Catalysis
- Information Systems
- Molecular Biology
- Drug Discovery
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry