Abstract
Background: Spiro[4.5]decenones are privileged structural motifs occurring in various biologically active natural and unnatural compounds. Moreover, they are very important intermediates in organic synthesis. Therefore, the development of novel onepot protocols for the synthesis of these synthetically challenging spirocyclic compounds that benefit from simple, inexpensive, and readily available starting materials continues to be a target of intense interest. In recent years, tremendous efforts have been made toward the construction of titled compounds form cheap and readily accessible N-arylpropiolamide derivatives through intramolecular ipso-cyclization strategy.
Objective/Methodology: This review highlights recent advances in this explosive growing research area from the year 2005 to 2017.
Conclusion: The review is divided into three major sections. The first section focuses exclusively on ipsohalocyclization approaches. The second section will discuss oxidative radical ipso-cyclizations. The third will cover catalytic ipso-cyclizations. Mechanistic aspects of the reactions are considered and discussed in detail.
Keywords: N-arylpropiolamides, azaspiro[4.5]decatrien-2-ones, ipso-cyclization, electrophilic cyclizations, tert-butyl hydroperoxide.
Graphical Abstract