Imperial College London

Professor Henry S. Rzepa

Faculty of Natural SciencesDepartment of Chemistry

Emeritus Professor of Computational Chemistry
 
 
 
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Contact

 

+44 (0)7514 623 653h.rzepa Website

 
 
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Location

 

501AMolecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Publication Type
Year
to

434 results found

Shernyukov AV, Genaev AM, Salnikov GE, Shubin VG, Rzepa HSet al., 2019, Elevated reaction order of 1,3,5-tri-tert-butylbenzene bromination as evidence of a clustered polybromide transition state: a combined kinetic and computational study., Org Biomol Chem, Vol: 17, Pages: 3781-3789

The kinetics and mechanism of concurrent bromo-de-protonation and bromo-de-tert-butylation of 1,3,5-tri-tert-butylbenzene at different bromine concentrations were studied experimentally and theoretically. Both reactions have high order in bromine (experimental kinetic orders ∼5 and ∼7, respectively). According to quantum chemical DFT calculations, such high reaction orders are caused by participation of clustered polybromide anions Br2n-1- in transition states. Bromo-de-tert-butylation has a higher order due to its bigger reaction center demanding clusters of extended size. A significant primary deuterium kinetic isotope effect (KIE) for bromo-de-protonation is measured indicating proton removal is rate limiting, as confirmed by computed DFT models. The latter predict a larger value for the KIE than measured and possible explanations for this are discussed.

JOURNAL ARTICLE

Du Y, Barber T, Lim SE, Rzepa HS, Baxendale IR, Whiting Aet al., 2019, A solid-supported arylboronic acid catalyst for direct amidation, CHEMICAL COMMUNICATIONS, Vol: 55, Pages: 2916-2919, ISSN: 1359-7345

JOURNAL ARTICLE

Barba A, Dominguez S, Cobas C, Martinsen DP, Romain C, Rzepa HS, Seoane Fet al., 2019, Workflows Allowing Creation of Journal Article Supporting Information and Findable, Accessible, Interoperable, and Reusable (FAIR)-Enabled Publication of Spectroscopic Data, ACS OMEGA, Vol: 4, Pages: 3280-3286, ISSN: 2470-1343

JOURNAL ARTICLE

Nielsen CD-T, Mooij WJ, Sale D, Rzepa HS, Bures J, Spivey ACet al., 2019, Reversibility and reactivity in an acid catalyzed cyclocondensation to give furanochromanes - a reaction at the "oxonium-Prins' vs. "ortho-quinone methide cycloaddition' mechanistic nexus, Chemical Science, Vol: 10, Pages: 406-412, ISSN: 2041-6520

Herein we report a combined experimental and computational investigation of the acid catalyzed cyclocondensation reaction between styrenyl homoallylic alcohols and salicylaldehyde to form furanochromanes. We disclose a previously unreported isomerisation of the ‘unnatural’ trans-fused products to the diastereomeric ‘natural’ cis-fused congeners. Notwithstanding the appeal of assuming this corresponds to endo to exo isomerisation of Diels–Alder (D–A) adducts via concerted retro-cycloaddition/cycloaddition reactions of an in situ generated ortho-quinone methide with the styrenyl alkene, our combined Hammett/DFT study reveals a stepwise Prins-like process via discrete benzylic carbocation intermediates for all but the most electron deficient styrenes. As these reactions fortuitously lie at the intersection of these two mechanistic manifolds, it allows us to propose an experimentally determined indicative ρ+ value of ca. −3 as marking this nexus between a stepwise Prins-type pathway and a concerted cycloaddition reaction. This value should prove useful for categorising other reactions formally involving ‘ortho-quinomethides’, without the need for the extensive computation performed here. Logical optimisation of the reaction based upon the mechanistic insight led to the use of HFIP as an additive which enables exclusive formation of ‘natural’ cis-fused products with a ∼100-fold reaction rate increase and improved scope.

JOURNAL ARTICLE

Sebest F, Casarrubios L, Rzepa HS, White AJP, Diez-Gonzalez Set al., 2018, Thermal azide-alkene cycloaddition reactions: straightforward multi-gram access to (2)-1,2,3-triazolines in deep eutectic solvents, GREEN CHEMISTRY, Vol: 20, Pages: 4023-4035, ISSN: 1463-9262

JOURNAL ARTICLE

Rzepa HS, Arkhipenko S, Wan E, Sabatini MT, Karaluka V, Whiting A, Sheppard TDet al., 2018, An accessible method for DFT calculation of B-11 NMR shifts of organoboron compounds, Journal of Organic Chemistry, Vol: 83, Pages: 8020-8025, ISSN: 0022-3263

The study of boron-mediated reactions in organic synthesis and reactions of organoboron compounds is greatly facilitated by the use of 11B NMR. However, the identification and characterization of reaction intermediates in often complex systems is far from trivial, as 11B NMR does not provide any detailed structural information. Greater insight into the structures present in such systems can be obtained by using DFT chemical shift calculations to support or exclude proposed reaction intermediates. In this article, we report a rapid and accessible approach to the calculation of 11B NMR shifts that is applicable to a wide range of organoboron compounds.

JOURNAL ARTICLE

Mandal D, Dhara D, Maiti A, Klemmer L, Huch V, Zimmer M, Rzepa HS, Scheschkewitz D, Jana Aet al., 2018, Mono- and Dicoordinate Germanium(0) as a Four-Electron Donor, CHEMISTRY-A EUROPEAN JOURNAL, Vol: 24, Pages: 2873-2878, ISSN: 0947-6539

JOURNAL ARTICLE

Arkhipenko S, Sabatini MT, Batsanov AS, Karaluka V, Sheppard TD, Rzepa HS, Whiting Aet al., 2018, Mechanistic insights into boron-catalysed direct amidation reactions, CHEMICAL SCIENCE, Vol: 9, Pages: 1058-1072, ISSN: 2041-6520

JOURNAL ARTICLE

Davies AN, Martinsen D, Rzepa HS, Romain C, Barba A, Seoane F, Dominguez S, Cobas Cet al., 2017, Simplifying spectroscopic supplementary data collection, Spectroscopy Europe, Vol: 29, Pages: 6-10, ISSN: 0966-0941

JOURNAL ARTICLE

Almond-Thynne J, White AJP, Polyzos A, Rzepa HS, Parsons PJ, Barrett AGMet al., 2017, Synthesis and Reactions of Benzannulated Spiroaminals: Tetrahydrospirobiquinolines, ACS OMEGA, Vol: 2, Pages: 3241-3249, ISSN: 2470-1343

JOURNAL ARTICLE

Abas H, Linsdall SM, Mamboury M, Rzepa HS, Spivey ACet al., 2017, Total Synthesis of (+)-Lophirone H and Its Pentamethyl Ether Utilizing an Oxonium-Prins Cyclization, ORGANIC LETTERS, Vol: 19, Pages: 2486-2489, ISSN: 1523-7060

JOURNAL ARTICLE

Murray JI, Floden NJ, Bauer A, Fessner ND, Dunklemann DL, Bob-Egbe O, Rzepa HS, Burgi T, Richardson J, Spivey ACet al., 2017, Kinetic Resolution of 2-Substituted Indolines by N-Sulfonylation using an Atropisomeric 4-DMAP-N-oxide Organocatalyst, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, Vol: 56, Pages: 5760-5764, ISSN: 1433-7851

JOURNAL ARTICLE

Murray JI, Flodén NJ, Bauer A, Fessner ND, Dunklemann DL, Bob-Egbe O, Rzepa HS, Bürgi T, Richardson J, Spivey ACet al., 2017, Kinetic Resolution of 2-Substituted Indolines by N -Sulfonylation using an Atropisomeric 4-DMAP- N -oxide Organocatalyst, Angewandte Chemie, Vol: 129, Pages: 5854-5858, ISSN: 0044-8249

JOURNAL ARTICLE

May PW, Cotton SA, Harrison K, Rzepa HSet al., 2017, The 'Molecule of the Month' Website-An Extraordinary Chemistry Educational Resource Online for over 20 Years, MOLECULES, Vol: 22, ISSN: 1420-3049

JOURNAL ARTICLE

Calbo J, Weston CE, White AJP, Rzepa HS, Contreras-Garcia J, Fuchter MJet al., 2017, Tuning Azoheteroarene Photoswitch Performance through Heteroaryl Design, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, Vol: 139, Pages: 1261-1274, ISSN: 0002-7863

JOURNAL ARTICLE

Harvey MJ, McLean A, Rzepa HS, 2017, A metadata-driven approach to data repository design, JOURNAL OF CHEMINFORMATICS, Vol: 9, ISSN: 1758-2946

JOURNAL ARTICLE

Andrade MS, Silva VS, Lourenco AM, Lobo AM, Rzepa HSet al., 2016, Chiroptical Properties of Streptorubin B: The Synergy Between Theory and Experiment (vol 27, pg 745, 2015), CHIRALITY, Vol: 28, Pages: 663-663, ISSN: 0899-0042

JOURNAL ARTICLE

Romain C, Zhu Y, Dingwall P, Paul S, Rzepa HS, Buchard A, Williams CKet al., 2016, Chemoselective Polymerizations from Mixtures of Epoxide, Lactone, Anhydride, and Carbon Dioxide, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, Vol: 138, Pages: 4120-4131, ISSN: 0002-7863

JOURNAL ARTICLE

Rzepa HS, 2016, Discovering More Chemical Concepts from 3D Chemical Information Searches of Crystal Structure Databases, JOURNAL OF CHEMICAL EDUCATION, Vol: 93, Pages: 550-554, ISSN: 0021-9584

JOURNAL ARTICLE

Vargas-Caamal A, Luis Cabellos J, Ortiz-Chi F, Rzepa HS, Restrepo A, Merino Get al., 2016, How Many Water Molecules Does it Take to Dissociate HCl?, CHEMISTRY-A EUROPEAN JOURNAL, Vol: 22, Pages: 2812-2818, ISSN: 0947-6539

JOURNAL ARTICLE

Shernyukov AV, Genaev AM, Salnikov GE, Rzepa HS, Shubin VGet al., 2016, Noncatalytic Bromination of Benzene: A Combined Computational and Experimental Study, JOURNAL OF COMPUTATIONAL CHEMISTRY, Vol: 37, Pages: 210-225, ISSN: 0192-8651

JOURNAL ARTICLE

Braddock DC, Mahtey A, Rzepa HS, White AJPet al., 2016, Stable bromoallene oxides, CHEMICAL COMMUNICATIONS, Vol: 52, Pages: 11219-11222, ISSN: 1359-7345

JOURNAL ARTICLE

McArdle I, Fare C, Bearpark M, Thomas G, Butcher S, Tomlinson C, Mueller M, Burbidge S, Lawlor S, Ferrer J, Rzepa H, Harvey M, Mclean A, Mason Net al., 2015, Research Data Management 'Green Shoots' Pilot Programme, Final Reports, Research Data Management 'Green Shoots' Pilot Programme, Final Reports

This document contains the final reports of six Research Data Management "Green Shoots" projects run at Imperial College in 2014.

REPORT

Andrade MS, Silva VS, Lourenco AM, Lobo AM, Rzepa HSet al., 2015, Chiroptical Properties of Streptorubin B: The Synergy Between Theory and Experiment, CHIRALITY, Vol: 27, Pages: 745-751, ISSN: 0899-0042

JOURNAL ARTICLE

Harvey MJ, Mason NJ, McLean A, Murray-Rust P, Rzepa HS, Stewart JJPet al., 2015, Standards-based curation of a decade-old digital repository dataset of molecular information, JOURNAL OF CHEMINFORMATICS, Vol: 7, ISSN: 1758-2946

JOURNAL ARTICLE

Harvey MJ, Mason NJ, McLean A, Rzepa HSet al., 2015, Standards-based metadata procedures for retrieving data for display or mining utilizing persistent (data-DOI) identifiers, JOURNAL OF CHEMINFORMATICS, Vol: 7, ISSN: 1758-2946

JOURNAL ARTICLE

Kuok KMH, Rzepa HS, Smith EH, 2015, Asymmetric Epoxidation: A Twinned Laboratory and Molecular Modeling Experiment for Upper-Level Organic Chemistry Students, JOURNAL OF CHEMICAL EDUCATION, Vol: 92, Pages: 1385-1389, ISSN: 0021-9584

JOURNAL ARTICLE

Jana A, Huch V, Rzepa HS, Scheschkewitz Det al., 2015, A Molecular Complex with a Formally Neutral Iron Germanide Motif (Fe2Ge2), ORGANOMETALLICS, Vol: 34, Pages: 2130-2133, ISSN: 0276-7333

JOURNAL ARTICLE

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