Frontispiece: Strain Release Chemistry of Photogenerated Small‐Ring Intermediates

Hantzsch Ester-Mediated Photochemical Transformations in the Ketone Series: Remote C(sp3)–H Arylation and Cyclopentene Synthesis through Strain Release

A metal-free Hantzsch ester-mediated synthesis of cyclopentenylketones as well as γ-hetarylketones starting from ketocyclopropanes under eco-friendly conditions was developed. The versatility of the developed conditions is shown by reacting ketocyclopropanes in both a formal [3 + 2] cycloaddition with terminal alkynes (further investigated using theoretical calculations) and a radical C-C-coupling with cyanopyridines. The newly developed methodologies were later on utilized as a downstream reaction for photogenerated cyclopropanes combining UV and visible light photochemistry. Following this procedure, a UV-driven Norrish-Yang-type reaction induces the ring strain of the intermediates, whic…

Strain Release Chemistry of Photogenerated Small‐Ring Intermediates

Abstract Photochemical processes, such as isomerizations and cycloadditions, have proven to be very useful in the construction of highly strained molecular frameworks. Photoinduced ring strain enables subsequent exergonic reactions which do not require the input of additional chemical energy and provides a variety of attractive synthetic options leading to complex structures. This review covers the progress achieved in the application of sequences combining excitation by ultraviolet light to form strained intermediates, which are further transformed to lower energy products in strain‐release reactions. As ring strain is considerable in small ring systems, photogenerated three‐ and four‐memb…

A Copper‐Catalyzed Synthesis of Pyrroles through Photochemically Generated Acylazirines

CCDC 1946259: Experimental Crystal Structure Determination

Related Article: Jan Paternoga, Till Opatz|2019|Eur.J.Org.Chem.|2019|7067|doi:10.1002/ejoc.201901176

CCDC 1946260: Experimental Crystal Structure Determination

Related Article: Jan Paternoga, Till Opatz|2019|Eur.J.Org.Chem.|2019|7067|doi:10.1002/ejoc.201901176