Imperial College London


Faculty of Natural SciencesDepartment of Chemistry

Visiting Researcher







110Molecular Sciences Research HubWhite City Campus





Publication Type

11 results found

Allen LAT, Raclea R-C, Natho P, Parsons PJet al., 2021, Recent advances in the synthesis of α-amino ketones, Organic & Biomolecular Chemistry, Vol: 19, Pages: 498-513, ISSN: 1477-0520

<p>This review on α-amino ketone synthesis collates and evaluates developments made in this area over the past decade, with an extended discussion on functional group compatibility, resultant product substitution patterns, and medicinal applications.</p>

Journal article

Natho P, Yang T, Allen L, Rey J, White A, Parsons Pet al., 2021, An entry to 2-(cyclobut-1-en-1-yl)-1H-indoles through a cyclobutenylation/deprotection cascade, Organic and Biomolecular Chemistry, ISSN: 1477-0520

Journal article

Natho P, Annie R, Greenfield J, Allen L, Andrew W, Yang T, Parsons Pet al., 2020, Regioselective synthesis of 1- and 4-tetralones from heteroaryl-3-cyclobutanols, Tetrahedron, Vol: 76, ISSN: 0040-4020

Herein we describe the first transition-metal-free ring expansion of four-membered rings to 1-tetralones from 3-substituted heteroaromatic compounds, and the first example of an oxetanol ring expansion to an oxa-tetralone. We also experimentally investigate the mechanism of the silver-mediated ring expansion and elucidate the active oxidant in these systems using electrochemical techniques.

Journal article

Raclea R-C, Natho P, Allen L, Andrew W, Parsons Pet al., 2020, Oxidative deconstruction of azetidinols to α-Amino ketones, Journal of Organic Chemistry, Vol: 85, Pages: 9375-9385, ISSN: 0022-3263

A silver-mediated synthesis of α-amino ketones via the oxidative deconstruction of azetidinols has been developed using a readily scalable protocol with isolated yields up to 80%. The azetidinols are easily synthesized in one step and can act as protecting groups for these pharmaceutically relevant synthons. Furthermore, mechanistic insights are presented and these data have revealed that the transformation is likely to proceed through the β-scission of an alkoxy radical, followed by oxidation and C–N cleavage of the resulting α-amido radical.

Journal article

Natho P, Allen LAT, Parsons PJ, 2020, Recent advances in the ring expansion of cyclobutanols, oxetanols, and azetidinols, Tetrahedron Letters, Vol: 61, Pages: 1-9, ISSN: 0040-4039

The number of developed methodologies for the ring expansion of cyclobutanol rings to five, six and seven-membered rings has increased significantly over the last six years. In this timeframe, the semipinacol rearrangement of vinyl-group containing cyclobutanols to cyclopentanones has been advanced under photoredox and electrochemical conditions, enabling the concomitant introduction of a wide array of functional groups. The expansion to 1- and 4-tetralones has been achieved for the first time under transition-metal-free conditions and even expansion to seven-membered rings has been demonstrated under rhodium catalysis. In this article, we will critically discuss the scope, application and mechanistic studies of procedures published since 2013, and provide a short outlook on the emerging potential for further development in this area.

Journal article

Natho P, Allen LAT, White AJP, Parsons PJet al., 2019, A transition-metal-free access to heteroaromatic-fused 4-tetralones by the oxidative ring expansion of the cyclobutanol moiety, The Journal of Organic Chemistry, Vol: 84, Pages: 9611-9626, ISSN: 0022-3263

Advances in the transition-metal-free cyclobutanol ring expansion to 4-tetralones under N-bromosuccinimide mediation are described. We have expanded the scope of this ring expansion methodology and investigated the effect substituents on the aromatic ring, and the cyclobutanol moiety, have on the outcome of the reaction. Limitations with certain substituents on the cyclobutanol moiety are also described. Further experimental evidence to support our mechanistic understanding is disclosed, and we now preclude the suggested involvement of a primary radical for this transformation.

Journal article

Natho P, Kapun M, Allen L, Parsons PJet al., 2018, Regioselective transition-metal-free oxidative cyclobutanol ring expansion to 4-tetralones, Organic Letters, Vol: 20, Pages: 8030-8034, ISSN: 1523-7052

A facile and transition-metal-free ring expansion of the cyclobutanol moiety to 4-tetralones fused to heteroaromatic systems is described. The oxidative ring expansion proceeds rapidly and regioselectively through mediation by N-bromosuccinimide and acetonitrile in satisfactory to good yields. The preparation of precursors, as well as the ring expansion have proven to be scalable and are straightforward to carry out

Journal article

Parsons PJ, Allen LAT, Jones DR, Padgham AC, Pryke JA, McKenna J, O'Reilly Det al., 2017, Approaches to the synthesis of highly substituted aromatic and fused rings: metal-catalysed versus thermal cyclisation, Synthesis, Vol: 50, Pages: 84-101, ISSN: 0039-7881

A domino reaction has been used for the construction of lactonamycin derivatives. This research led to a comparison study between palladium-mediated cascade cyclisations and thermal alkyne [2+2+2] cyclisations. A palladium-mediated cyclisation of alkenyl bromides with alkynes and furans has been shown to furnish highly substituted aromatic rings. Penta- and hexasubstituted aromatic rings have also been prepared by the thermolysis of suitably substituted alkynes under microwave conditions. Tetrasubstituted pyridines can also be prepared using nitriles instead of alkynes. This work will provide a new and interesting array of drug templates; mechanistic details are discussed for both reaction series.

Journal article

Parsons PJ, Jones DR, Walsh LJ, Allen LAT, Onwubiko A, Preece L, Board J, White AJPet al., 2017, An approach to the core of lactonamycin, Organic Letters, Vol: 19, Pages: 2533-2535, ISSN: 1523-7060

A cascade reaction has been developed for the synthesis of lactonamycin. In this paper, we demonstrate that a transition-metal-free thermal ene–diyne cyclization can be used for the construction of the entire core of the antibiotic lactonamycin and anticancer agent lactonamycin Z.

Journal article

Parsons PJ, Jones DR, Padgham AC, Allen LAT, Penkett CS, Green RA, White AJPet al., 2016, ChemInform Abstract: A New Approach for the Synthesis of Highly Substituted Aromatic Rings: The Alkyne-Mediated Approach., ChemInform, Vol: 47, ISSN: 0931-7597

Journal article

Parsons PJ, Jones DR, Padgham AC, Allen LAT, Penkett CS, Green RA, White AJPet al., 2016, A New Approach for the Synthesis of Highly Substituted Aromatic Rings: The Alkyne-Mediated Approach, CHEMISTRY-A EUROPEAN JOURNAL, Vol: 22, Pages: 3981-3984, ISSN: 0947-6539

Journal article

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: Request URI: /respub/WEB-INF/jsp/search-html.jsp Query String: respub-action=search.html&id=00728526&limit=30&person=true