Continuing developments
in the elucidation techniques of complex catalytic processes is of
foremost importance to modern synthetic chemistry, and the identification
of efficient synthetic techniques relies on precise, reliable, and
adaptable methods to dissect the mechanism of a given transformation.
Currently, methods of reaction development are grounded upon the systematic
modification of specific variablessuch as temperature, time,
concentration, etc.to account for and control the dynamic
series of coupled equilibria within a catalytic environment. On the
other hand, tandem reaction analytical methods that involve the concomitant
use of different instruments to probe a reaction can provide time-resolved
information regarding active chemical species and facilitate the interrogation
and optimization of the system. Herein, we report our study applying
tandem in situ ReactIR and HPLC-MS monitoring to the dysprosium(III)
triflate-catalyzed aza-Piancatelli rearrangement of 2-furylcarbinols,
a reaction that grants access to <i>trans</i>-4,5-disubstituted
cyclopentenonescommon motifs in important biologically relevant
and natural compounds. With a prototype automated sampling apparatus,
information was obtained about the intrinsic chemoselectivity of the
reaction, and previously unseen intermediates were observed, allowing
for a more detailed reaction mechanism to be substantiated. The advantages
of applying this type of tandem measurement to study these types of
systems are also discussed
