Although alkyl azides are known to typically form imines under direct irradiation, the product formation mechanism remains ambiguous as some alkyl azides also yield the corresponding triplet alkylnitrenes at cryogenic temperatures. The photoreactivity of 3‐azido‐3‐phenyl‐3
- Award ID(s):
- 2102248
- NSF-PAR ID:
- 10445874
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Photochemistry and Photobiology
- Volume:
- 97
- Issue:
- 6
- ISSN:
- 0031-8655
- Page Range / eLocation ID:
- p. 1397-1406
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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To enhance the versatility of organic azides in organic synthesis, a better understanding of their photochemistry is required. Herein, the photoreactivity of azidoisoxazole 1 was characterized in cryogenic matrices with IR and UV-Vis absorption spectroscopy. The irradiation (λ = 254 nm) of azidoisoxazole 1 in an argon matrix at 13 K and in glassy 2-methyltetrahydrofuran (mTHF) at 77 K yielded nitrosoalkene 3. Density functional theory (DFT) and complete active space self-consistent field (CASSCF) calculations were used to aid the characterization of nitrosoalkene 3 and to support the proposed mechanism for its formation. It is likely that nitrosoalkene 3 is formed from the singlet excited state of azidoisoxazole 1 via a concerted mechanism or from cleavage of an intermediate singlet nitrene that does not undergo efficient intersystem crossing to its triplet configuration.more » « less
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