Organic Chemistry Seminar: Donor-Acceptor Cyclopropanes: Unique Structural Units to Access Carbo- and Heterocyclic Compounds
Prof. Daniel Werz, University of Braunschweig
Donor-acceptor (DA) cyclopropanes are highly strained entities which are unique building blocks for heterocyclic and carbocyclic systems.[1,2] Our previous work was mainly focused on rearrangement reactions of DA cyclopropanes leading to spiroketals, oligoacetals, pyrrols and thiophenes The recent developments in the lab deal with [3+n]-cycloaddition (n = 1, 2, 3, 4) and ring-opening reactions of these three-membered rings systems.
Approaches to four-membered ring formation by insertion of one atom are presented. The formation of five-membered rings with unusual 2-atom moieties being inserted are discussed or by dual Lewis acid and redox catalysis converting an electrophile in situ into a nucleophile. [3+3]-Cycloaddition reactions using carbonyl ylides allow the preparation of complex bicyclic scaffolds in a simple manner. 1,3-Bisfunctionalization studies pave the way to 1,4-bisamines by the formal addition of “NHR” and “CH2NHR” to the 1- and 3-position of the cyclopropane.
 H.-U. Reißig, R. Zimmer, Chem. Rev. 2003, 103, 1151-1196.
 D. B. Werz, J. Kaschel, D. B. Werz, Angew. Chem. Int. Ed. 2014, 53, 5504-5523.
 T. F. Schneider, J. Kaschel, S. I. Awan, B. Dittrich, D. B. Werz, Chem. Eur. J. 2010, 16, 11276-11288.
 J. Kaschel, T. F. Schneider, D. Kratzert, D. Stalke, D. B. Werz, Angew. Chem. Int. Ed. 2012, 51, 11153-11156.
 a) L. K. B. Garve, M. Pawliczek, J. Wallbaum, P. G. Jones, D. B. Werz, Chem. Eur. J. 2016, 22, 521-525. b) L. K. B. Garve, M. Petzold, P. G. Jones, D. B. Werz, Org. Lett. 2016, 18, 564-567. c) J. Wallbaum, L. K. B. Garve, P. G. Jones, D. B. Werz, Org. Lett. 2017, 19, 98-101.
 A. U. Augustin, M. Sensse, P. G. Jones, D. B. Werz, Angew. Chem. Int. Ed. 2017, 56, 14293-14296.
 A. Lücht, L. J. Patalag, A. U. Augustin, P. G. Jones, D. B. Werz, Angew. Chem. Int. Ed. 2017, 56, 10587-10591.
 L. K. B. Garve, P. G. Jones, D. B. Werz, Angew. Chem. Int. Ed. 2017, 56, 9226-9230.
Seminar Organizer: Dr. Roman Dobrovetsky