Medium and Substituent Effects on the Photochemistry of Phenanthridine N-Oxides. Is an Intermediate of Diradical Character involved in the Photorearrangement of Heterocyclic N-Oxides?

DOI: 10.1039/P29880000235

Source and publish data:

Journal of the Chemical Society. Perkin transactions II p. 235 - 240 (1988)

Update date:2022-07-29

Topics:

Authors:

Albini, Angelo

Fasani, Elisa

Frattini, Valeria

Read Full Text PDF DownLoad Join now for total 90,000,000 free articles

Article abstract of DOI:10.1039/P29880000235

The photochemistry of several 6-substituted phenanthridine N-oxides has been investigated, or reinvestigated, in benzene and ethanol.The main processes observed are: (a) 1,2-oxygen and substituent shift to yield N-substituted phenanthridones (2) and (b) ring enlargements to dibenzo-1,3-oxazepines (7).With 6-diphenylmethylphenanthridine N-oxide (1b) rearrangement (a) predominates and occurs with 45percent substituent loss in benzene (but only 2percent in ethanol).With the 6-phenylderivative (1c) process (a) predominates in ethanol and process (b) in benzene and with the 6-p-nitrophenyl derivative (1d) the latter process predominates in both solvents.With 6-cyanophenanthridine N-oxide (1e) rearrangement (b) predominates in benzene; in the presence of 2,3-dimethylbutene (but not of cyclohexene) addition products are obtained; with dienes deoxygenation is the main process.Medium and substituents may change the nature of the lowest excited singlet state, but more importantly affect the stability of an intermediate of diradical character occurring along the reaction pathway, thus driving it towards rearrangement (a) or (b).Intermediate diradicals are unambiguously indicated only in particular cases but their role is probably more general.

Full text of DOI:10.1039/P29880000235

View Article Online / Journal Homepage / Table of Contents for this issue

View Article Online

Products guided by the article

Product name:2-(2-hydroxyphenyl)-N-(p-nitrobenzoyl)aniline

Cas No:116449-43-5

R&D Labs maybe for 116449-43-5

C-LAB Chemievermittlung GmbH

Contact:+49-9398-993127

Address:Untertorstr. 27
YanCheng LongShen Chemical Co.,Ltd.

Contact:+86-515-86668866

Address:No.13,Weiyi Road,Funing Aoyang Industrial Park
Chengdu CSH Pharmaceutical Co.,ltd

Contact:+86-(28)-85321971

Address:Block B,New Hope Int. Tian Fu New District, Chengdu, Sichuan, China
Geen Chemical Technology Co., Ltd

Contact:86-769-21660847

Address:1408, Yingfeng Commercial Center, Nancheng District
ShangHai Ruiyi Medical Technology Co.,Ltd.

Contact:+86-21-54718086

Address:No951 Jianchuan RD，Minhang District

Relevant to this article

Inhibition of tumor cell growth and angiogenesis by 7-Aminoalkoxy-4- aryloxy-quinazoline ureas, a novel series of multi-tyrosine kinase inhibitors

Doi:10.1016/j.ejmech.2014.04.007
(2014)
Asymmetric Ring-Closing Aminooxygenation of Alkenes en Route to 2-Amino-1,3-Diols with Vicinal Stereocenters

Doi:10.1021/acs.orglett.0c02452
(2020)
Oxidant-Controlled C-sp²/sp³-H Cross-Dehydrogenative Coupling of N-Heterocycles with Benzylamines

Doi:10.1021/acs.joc.7b00856
(2017)
Palladium-Catalyzed Phosphoryl-Carbamoylation of Alkenes: Construction of Nonbenzylic C(sp³)?P(O)R₂ Bonds via C(sp³)?Pd(II)?P(O)R₂ Reductive Elimination

Doi:10.1002/adsc.202000337
(2020)
Novel arylated chloro- and methoxy-1,3-dibutadienes: Influence of substituents on molecular conformation and crystal packing

Doi:10.1016/j.molstruc.2014.04.028
(2014)
Synthesis and pharmacological evaluation of analogues of benzyl quinolone carboxylic acid (BQCA) designed to bind irreversibly to an allosteric site of the M₁ muscarinic acetylcholine receptor

Doi:10.1021/jm500556a
(2014)

Article Doi