Stephanie Suzanne Madeleine Spoehrle

  • School of Chemistry
  • Purdie Building North Haugh
  • St Andrews
  • KY16 9ST
  • United Kingdom

 

My SuBiCat publications:

 

2017   Isothiourea-catalysed chemo- and enantioselective [2,3]-sigmatropic rearrangements of N,N-diallyl allylic ammonium ylides

T. H. West, S. S. M. Spoehrle, A. D. Smith, Tetrahedron Volume 73, Issue 29, 20 July 2017, Pages 4138-4149

The isothiourea-catalysed chemo- and enantioselective [2,3]-sigmatropic rearrangement of N,N-diallyl allylic ammonium ylides is explored as a key part of a route to free functionalised ?-amino esters and piperidines. The [2,3]-sigmatropic rearrangement proceeds with excellent diastereo- and enantiocontrol (>95:5 dr, up to 97% ee), with the resultant N,N-diallyl ?-amino esters undergoing either mono- or bis-N-allyl deprotection. Bis-N-allyl deprotection leads to free ?-amino esters, while the mono-deprotection strategy has been utilized in the synthesis of a target functionalised piperidine.undergoing either - or -allyl deprotection. Bis -allyl deprotection leads to free -amino esters, while the mono-deprotection strategy has been utilized in the synthesis of a target functionalised piperidine.

2017  Tandem Palladium and Isothiourea Relay Catalysis: Enantioselective Synthesis of α-Amino Acid Derivatives via Allylic Amination and [2,3]-Sigmatropic Rearrangement

S. S. M. Spoehrle, T. H. West, J. E. Taylor, A. M. Z. Slawin, A. D. Smith, J. Am. Chem. Soc., 2017, 139 (34), pp 11895–11902

A tandem relay catalytic protocol using both Pd and isothiourea catalysis has been developed for the enantioselective synthesis of α-amino acid derivatives containing two stereogenic centers from readily accessible N,N-disubstituted glycine aryl esters and allylic phosphates. The optimized process uses a bench-stable succinimide-based Pd precatalyst (FurCat) to promote Pd-catalyzed allylic ammonium salt generation from the allylic phosphate and the glycine aryl ester. Subsequent in situ enantioselective [2,3]-sigmatropic rearrangement catalyzed by the isothiourea benzotetramisole forms syn-α-amino acid derivatives with high diastereo- and enantioselectivity. This methodology is most effective using 4-nitrophenylglycine esters and tolerates a variety of substituted cinnamic and styrenyl allylic ethyl phosphates. The use of challenging unsymmetrical N-allyl-N-methylglycine esters is also tolerated under the catalytic relay conditions without compromising stereoselectivity.

2015  Catalytic Stereoselective [2,3]-Rearrangement Reactions

Thomas H. West, Stéphanie S. M. Spoehrle, Kevin Kasten, James E. Taylor, and Andrew D. Smith, ACS Catal., 2015, 5 (12), pp 7446–7479

[2,3]-Sigmatropic rearrangement processes of allylic ylides or their equivalents can be applied to a variety of different substrates and generate products of wide interest/applicability to organic synthesis. This review describes the development and applications of stereoselective [2,3]-rearrangement reactions in which a substoichiometric amount of a catalyst is used in either the formation of the reactive intermediate or the [2,3]-rearrangement step itself.

My SuBiCat poster presentations:

 

Tandem catalytic and enantioselective [2,3]-rearrangement of allylic ammonium ylides

20th European Symposium on Organic Chemistry (ESOC 2017), Cologne, Germany, July 2016

 

Domino catalytic asymmetric [2,3]-rearrangement of allylic ammonium ylides

Industry Chemistry Forum, St Andrews, UK, September 2016

 

Tandem catalytic and enantioselective [2,3]-rearrangement of allylic ammonium ylides

School of Chemistry Postgraduate Symposium, St Andrews, UK, December 2016

 

Tandem catalytic and enantioselective [2,3]-rearrangement of allylic ammonium ylides

RSC Organic Division Poster Symposium, London, UK, December 2016

 

Domino catalytic and enantioselective [2,3]-rearrangements of allylic ammonium ylides

5th UK - Japanese Asymmetric Catalysis Symposium, Manchester, UK, March 2016

 

 

E-mail: ss286@st-andrews.ac.uk

Direct phone: +44 (0)7908193788