Development of a Continuous Flow Photoisomerization Reaction Converting Isoxazoles into Diverse Oxazole Products

A continuous flow process is presented,
which directly converts
isoxazoles into their oxazole counterparts via a photochemical transposition
reaction. This results in the first reported exploitation of this
transformation to establish its scope and synthetic utility. A series
of various di- and trisubstituted oxazole products bearing different
appendages including different heterocyclic moieties were realized
through this rapid and mild flow process. Furthermore, the robustness
of this approach was demonstrated by generating gram quantities of
selected products while also providing insights into likely intermediates.