Nitrones are important intermediates in organic syntheses. As spin traps they allow
for trapping of short-lived radicals, mainly reactive oxygen species (ROS), under
formation of relatively stable nitroxides. Fluorescent nitrones also offer the possibility
to follow the formation of ROS with subcellular resolution. To this end, particularly
stilbenenitrones have been employed. Here, we describe the synthesis of a series of
stilbenenitrones from aldehyde precursors prepared by an optimized, mild Heck-type
reaction. Rather unstable benzene diazonium salts required special conditions for
the trans-selective reaction with styrylsilanes. Moreover, a new method was developed to produce
stilbenenitrones quantitatively in most cases. Ab initio methods were used to clarify
an anomaly with respect to absorption behavior.
Key words
ROS - spin traps - diazonium salts - nitrones - Heck reaction
