The Organic Seminar Series presents - Daniel Werz

The Organic Seminar Series presents: Daniel Werz 

University of Freiburg

Host: Mike Krische

Title: Gain by Strain: Donor-Acceptor Cyclopropanes to Access Carbo- and Heterocyclic Compounds

Location: WEL 2.122

Refreshments served at 3:15pm

Donor-acceptor cyclopropanes (DACs) are highly strained entities which are unique building blocks for hetero- and carbocyclic systems.^1,2 For the last decade, we have been developing novel methodologies starting from these type of three-membered rings leading to oligopyrroles, chalcogen-containing heterocycles, and 1,3-bisfunctionalized products,³ just to name a few. To get deeper insights into their intrinsic reactivity in-depth physical organic studies were performed recently.⁴ 

Besides the common activation of DACs by Lewis acids leading to a wide variety of ring-opening and cycloaddition products even synergistic catalytic approaches can be applied to generate fleeting intermediates which react with the strained systems. Scheme 1 depicts two representative examples, one using Lewis acid and Rh catalysis (affording intermediate carbonyl ylides)⁵ and another using Lewis acid and redox catalysis are presented.⁶ More recently, electrochemical methods were applied to activate donor-acceptor cyclopropanes.⁷

[1] H.-U. Reissig, R. Zimmer, Chem. Rev. 2003, 103, 1151. 

[2] T. F. Schneider, J. Kaschel, D. B. Werz, Angew. Chem. Int. Ed. 2014, 53, 5504.

[3] a) J. Kaschel, T. F. Schneider, D. Kratzert, D. Stalke, D. B. Werz, Angew. Chem. Int. Ed. 2012, 51, 11153; b) A. U. Augustin, M. Sensse, P. G. Jones, D. B. Werz, Angew. Chem. Int. Ed. 2017, 56, 14293; c) L. K. B. Garve, P. G. Jones, D. B. Werz, D. B. Angew. Chem. Int. Ed. 2017, 56, 9226; d) G. A. Oliver, M. N. Loch, A. U. Augustin, P. Steinbach, M. Sharique, U. K. Tambar, P. G. Jones, C. Bannwarth, D. B. Werz, Angew. Chem. Int. Ed. 2021, 60, 25825. 

[4] A. Kreft, A. Lücht, J. Grunenberg, P. G. Jones, D. B. Werz, Angew. Chem. Int. Ed. 2019, 58, 1955. 

[5] M. Petzold, P. G. Jones, D. B. Werz, Angew. Chem. Int. Ed. 2019, 58, 6225. 

[6] A. Lücht, L. J. Patalag, A. U. Augustin, P. G. Jones, D. B. Werz, Angew. Chem. Int. Ed. 2017, 56, 10587. 

[7] S. Kolb, M. Petzold, F. Brandt, P. G. Jones, C. R. Jacob, D. B. Werz, Angew. Chem. Int. Ed. 2021, 60, 15928.