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Title: Synthetic, spectroscopic and computational studies of aromatic compounds : structure, fragmentation and novel dimerisation of indoles under electrospray conditions, and innovative nitrogen to carbon rearrangement of orthogonally protected sulphonamides and related compounds
Author: Saidykhan, A.
ISNI:       0000 0004 6495 5623
Awarding Body: University of Bradford
Current Institution: University of Bradford
Date of Award: 2015
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The complementary value of vibrational spectroscopy and mass spectrometry in obtaining structural information on a range of tricyclic indoles with various ring patterns has been investigated, focusing particularly on whether these heterocycles with a functional group containing oxygen in the third ring should be described as ketoindoles or hydroxindolenines. Parallels between certain fragmentations of ionised indoles and electrophilic substitution in solution have been identified. A mechanistically interesting and analytically useful interesting dimerisation, leading to the formation of [2M-H]+ ions, has been discovered in the positive ion electrospray mass spectra of 3-alkylindoles. This dimerisation, which occurs in the nebuliser of the instrument, offers a potential new route to bisindoles under milder conditions than those employed in classical solution chemistry. Facile formation of C=N bonds by condensation of C=O and H2N has been shown to provide a means of preparing protonated imines and protonated quinoxalines from mixtures of the requisite (di)carbonyl compounds and (di)amines, thus further illustrating how organic synthesis is possible in the droplets in the nebuliser of the instrument. Possible metal catalysed coupling reaction routes to bisindoles have been explored. Acyl transfer reactions from nitrogen to carbon have been investigated in 1-acyl-2-methylindoles and orthogonally protected sulphonamides. These processes have been shown to be intermolecular and intramolecular, respectively. The latter rearrangement, which may be prevented when necessary by choosing the nitrophenylsulphonamide protecting group, offers a route to acyl, carboalkoxy and carboaryloxy aromatic compounds, some of which are difficult to prepare.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Indoles ; Tetrahydrocarbazoles ; Mass Spectrometry ; Aromatic Compounds ; Vibrational Spectroscopy ; Dimerisation ; Electrospray ; Fragmentation ; Rearrangement ; Sulphonamides.