Photoracemization at a chiral pyramidal nitrogen centre

Bjørgo, Johannes; Boyd, Derek R.; Campbell, Rose M.; Neill, David C.

doi:10.1039/c39760000162

Cited by 15 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nitrones are known to transform to oxaziridines when irradiated [25,37,41,46,47,48]. Therefore, isolated aldonitrone 1 was exposed to light in H 2 O in an ice bath, with a glass filter (λ cut-off 300 nm).…”

Section: Resultsmentioning

confidence: 99%

“…In addition to the direct oxidation products of mnm 5 U mentioned above, other possible oxidation-derived products might form in vivo, such as the oxaziridine derivatives (for instance 3 and 4) (Scheme 3) observed upon light irradiation of aldonitrone 1 (Figure 5). Irradiation of 2 was not studied but should also lead to the corresponding oxaziridines since the light-dependent isomerization of aldonitrones is rather classic [37,41,46,47,48]. As cyclic constrained compounds oxaziridines are less stable than aldonitrones.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Oxidation of 5-methylaminomethyl uridine (mnm5U) by Oxone Leads to Aldonitrone Derivatives

et al. 2018

View full text Add to dashboard Cite

Oxidative RNA damage is linked to cell dysfunction and diseases. The present work focuses on the in vitro oxidation of 5-methylaminomethyl uridine (mnm5U), which belongs to the numerous post-transcriptional modifications that are found in tRNA. The reaction of oxone with mnm5U in water at pH 7.5 leads to two aldonitrone derivatives. They form by two oxidation steps and one dehydration step. Therefore, the potential oxidation products of mnm5U in vivo may not be only aldonitrones, but also hydroxylamine and imine derivatives (which may be chemically more reactive). Irradiation of aldonitrone leads to unstable oxaziridine derivatives that are susceptible to isomerization to amide or to hydrolysis to aldehyde derivative.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Oxidation of 5-methylaminomethyl uridine (mnm5U) by Oxone Leads to Aldonitrone Derivatives

et al. 2018

View full text Add to dashboard Cite

show abstract

“…A change from N-methyl to N-tertbutyl in 28, for example, results in an 8 x 10 3 increase in rate (29). Photoracemization of oxaziridines involves C-O bond cleavage to form the nitrone RN(0)=CR 2 , which rearranges back to the oxaziridine (51). Photoracemization of oxaziridines involves C-O bond cleavage to form the nitrone RN(0)=CR 2 , which rearranges back to the oxaziridine (51).…”

Section: E Reactions and Properties Ofchiral Oxaziridinesmentioning

confidence: 99%

Synthesis and Utilization of Compounds with Chiral Nitrogen Centers

Davis

1984

Asymmetric Synthesis

View full text Add to dashboard Cite

“…Photo‐irradiation studies on the open chain N ‐alkyl‐α‐phenylnitrones were first extensively studied by Emmons 16 which was followed by the work of Splitter 17–19 and Boyd groups 20–26 . These include the above‐mentioned PBN system along with its derivatives.…”

Section: Introductionmentioning

confidence: 99%

“…Photo-irradiation studies on the open chain N-alkyl-α-phenylnitrones were first extensively studied by Emmons 16 which was followed by the work of Splitter [17][18][19] and Boyd groups. [20][21][22][23][24][25][26] These include the above-mentioned PBN system along with its derivatives. All these studies revealed that oxaziridines are the photo-products of these nitrones.…”

mentioning

confidence: 99%

A computational investigation on the photochemistry of the popular spin‐trap agent N‐tert‐butyl‐α‐phenylnitrone (PBN) and thermal isomerization pathways of its photoproduct oxaziridine

Nikam,

Chattopadhyay

2024

Int J of Quantum Chemistry

View full text Add to dashboard Cite

Computational investigation on the low‐lying photo‐excited states of N‐tert‐butyl‐α‐phenylnitrone (PBN), a well‐known spin‐trap agent, has revealed its photo‐product (oxaziridine) formation channel. The S0‐S2 vertical excitation in PBN is subsequently followed by a non‐radiative decay pathway through S2/S1 and S0/S1 conical intersections (CIs) with CNO‐kinked structures, situated around 23 kcal/mol and 45 kcal/mol below the vertically excited S2 state, respectively. The reverse photo‐process of PBN formation involves photo‐excitation of oxaziridine to its S2 and S3 photo‐excited states. The forward photo‐isomerization leads to the trans‐oxaziridine with a backside CNO kink (trans‐OXB) while the reverse path studied by us, connects its front‐side CNO‐kinked analogue (trans‐OXF) with the PBN. Our search for the reverse thermal reaction paths from these two oxazirdines has led to their corresponding transition states, one at 35 kcal/mol and the other at 27 kcal/mol above trans‐OXF and trans‐OXB geometries, respectively. They lead to two different isomers (E and Z) of PBN which supports the reported nature of products from the trans‐oxaziridine in this thermal reaction. The inversion path of the chiral nitrogen atom of this N‐tert‐butyl‐oxaziridine (barrier 21 kcal/mol) has also been tracked. This reaction path has been compared with that of the N‐methyl (barrier 30 kcal/mol) and N‐acyl (barrier 10.5 kcal/mol) oxaziridine analogues.

show abstract

Photoracemization at a chiral pyramidal nitrogen centre

Cited by 15 publications

References 0 publications

Oxidation of 5-methylaminomethyl uridine (mnm5U) by Oxone Leads to Aldonitrone Derivatives

Oxidation of 5-methylaminomethyl uridine (mnm5U) by Oxone Leads to Aldonitrone Derivatives

Synthesis and Utilization of Compounds with Chiral Nitrogen Centers

A computational investigation on the photochemistry of the popular spin‐trap agent N‐tert‐butyl‐α‐phenylnitrone (PBN) and thermal isomerization pathways of its photoproduct oxaziridine

Contact Info

Product

Resources

About