Synthesis of new 1-Vinyl and 1-Alkynyl Triazenes

The recent discovery of an N2O-based synthesis of triazenes in our group has enabled the synthesis and investigation of 1-alkynyl triazenes. Early studies showed their potential for a functional group tolerant synthesis of 1-vinyl triazenes, which is further elaborated in this thesis. Furthermore, limitations in the synthesis of 1-alkynyl triazenes are addressed. In the first part of the work, a Rh-catalyzed annulation reaction of 1-alkynyl triazenes with bifunctional boronic acids is presented. Indenyl triazenes were obtained and the acid-induced cleavage of the triazene group was studied. Furthermore, cyclobutenyl triazenes were synthesized by Ficini-type cycloadditions of 1-alkynyl triazenes to electron deficient alkenes under Lewis-acid catalysis. Depending on the starting material, rearrangement of the addition products to bicyclooctenyl triazenes and subsequent derivatization was achieved. New 1-alkynyl triazenes were synthesized among others hydroxy substituted 1-alkynyl triazenes. The latter allow the synthesis of a terminal 1-alkynyl triazene, which can be derivatized to include a range of functional groups incompatible with the classical N2O-based synthesis of 1-alkynyl triazenes. Finally, the cytotoxicity of some of the newly synthesized 1-alkynyl and 1-vinyl triazenes was assessed.