2025/08/02 by Ferdinand L. Pointner, Jonas Poll, Elina K. Taskinen +10 · 1 voice
Chemistry · Energy · #Cyclopropane Reaction Mechanisms #CO2 Reduction Techniques and Catalysts #Chemical Reactions and Mechanisms
paper · doi:10.1002/ceur.202500133
openalex publication_date 2025/08/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/21
An in‐depth mechanistic study for the photogeneration of free diazoalkanes from N ‐tosylhydrazone precursors by combining observations from synthesis with spectroscopic and theoretical methods is presented. The N ‐tosylhydrazones have been previously established as donors for alkyl diazo species upon light irradiation, but exact mechanistic details of this photodissociation have remained elusive. Investigations of cyclohexane tosylhydrazone (CyNNTsH) by time‐resolved FTIR spectroscopy proved the role of the deprotonated CyNNTs − as the light‐harvesting species and revealed an intricate dependency of the thermal lifetime of the resulting diazoalkane on the deprotonating base. Computational studies including multiple approaches and levels of theory as well as rigorous benchmarking elucidated the dissociation mechanism via an allowed charge transfer state, a resulting destabilization of the dissociating bond, and a fast change of electronic character of the S 1 . These insights allow to suggest specific reaction conditions for photolabile or previously incompatible reaction partners thus paving way towards photo‐orthogonal synthetic strategies.