Metal-free C-H functionalisation methods

Previously held under moratorium from 1 December 2016 until 6 December 2021This thesis describes the development of two metal-free C–H functionalisation methods which encompass oxidations of sp³- and sp²-hybridised C–H bonds.Chapter 1 provides a brief introduction to the rapidly growing area of C–H functionalisation and outlines selected metal-catalysed and metal-free C–H functionalisation methods. Chapter 2 describes the development of a novel metal-free C–H functionalisation method of alkanes, from concept, through initial investigations, optimisation and substrate scope to mechanistic studies. Chapter 3 gives a detailed account of the development and mechanistic investigations of peroxide-mediated C–H functionalisation method exclusive to aromatic C–H bonds. Chapter 4 presents the experimental data obtained in the process of developing the new methodologies described herein. Chapter 5 contains an appendix. Chapter 6 contains a bibliography.This thesis describes the development of two metal-free C–H functionalisation methods which encompass oxidations of sp³- and sp²-hybridised C–H bonds.Chapter 1 provides a brief introduction to the rapidly growing area of C–H functionalisation and outlines selected metal-catalysed and metal-free C–H functionalisation methods. Chapter 2 describes the development of a novel metal-free C–H functionalisation method of alkanes, from concept, through initial investigations, optimisation and substrate scope to mechanistic studies. Chapter 3 gives a detailed account of the development and mechanistic investigations of peroxide-mediated C–H functionalisation method exclusive to aromatic C–H bonds. Chapter 4 presents the experimental data obtained in the process of developing the new methodologies described herein. Chapter 5 contains an appendix. Chapter 6 contains a bibliography

Brønsted Acid-Catalyzed Straightforward Synthesis of Benzo[b]carbazoles from 2,3-Unsubstituted Indoles

Described is a general and efficient synthesis of valuable benzo[b]carbazoles by Brønsted acid-catalyzed reactions between simple C-2,C-3-unsubstituted indoles and ortho-[α-(hydroxy)benzyl]benzaldehyde acetals. Highly selective migration processes are involved as key steps in the overall cascade sequence that involves the one-pot formation of two new bonds and a cycle in a regioselective fashion.Ministerio de Economia y Competitividad (MINECO) and FEDER (CTQ2010-15358) for financial suuport. P. G.-G. and M.A.F.-R. thank MINECO for "Juan de la Cierva" and "Ramon y Cajal" contractsThis is the peer reviewed version of the following article: Suárez, A., García-García, P., Fernández-Rodríguez, M. A. and Sanz, R. (2014), Brønsted Acid-Catalyzed Straightforward Synthesis of Benzo[b]carbazoles from 2,3-Unsubstituted Indoles. Adv. Synth. Catal., 356: 374–382. doi: 10.1002/adsc.201300868, which has been published in final form at 10.1002/adsc.201300868. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving

Arene oxidation with malonoyl peroxides

Malonoyl peroxide 7, prepared in a single step from the commercially available diacid, is an effective reagent for the oxidation of aromatics. Reaction of an arene with peroxide 7 at room temperature leads to the corresponding protected phenol which can be unmasked by aminolysis. An ionic mechanism consistent with the experimental findings and supported by isotopic labeling, Hammett analysis, EPR investigations and reactivity profile studies is proposed

Nanoporous aluminosilicate catalyzed Friedel–Crafts alkylation reactions of indoles with aldehydes and acetals

Nanoporous aluminosilicate materials efficiently catalyze Friedel-Crafts reactions of indoles to produce bisindolylalkane products. These reactions proceed rapidly and in high yields when acetals are used in place of the more commonly used carbonyl reagents. It is possible to capitalise on the large difference in the rates of reaction observed with aldehydes and acetals to develop a tandem acetalization-Friedel-Crafts protocol in which the acetal is generated in situ and undergoes subsequent reaction. © 2011 The Royal Society of Chemistry

Nanoporous aluminosilicate mediated transacetalization reactions: application in glycerol valorization

Nanoporous silicate materials, produced using an evaporation-induced self-assembly (EISA) approach, are highly effective catalysts for transacetalization reactions. Both acyclic acetals and ketals undergo rapid exchange in the presence of low loadings of nanoporous aluminosilicate materials and diols and triols to generate the corresponding cyclic acetals and ketals in excellent yield. The protocol is rapid, employs mild conditions, and the catalyst can be recycled a number of times without loss of activity