Synthesis and Applications of Stenhouse Salts and Derivatives

In recent years, Stenhouse salts have attracted much attention as intermediates for the synthesis of cyclopenten‐2‐enones. This Minireview aims to present an overview of the methods for preparation, further transformation and applications of Stenhouse and Stenhouse‐like salts. In this context, the Piancatelli rearrangement and its variants, and the recently reported donor–acceptor Stenhouse salts (DASA) will be addressed. The photophysical properties of DASA and its applications in colorimetric detection of amines, functionalization of polymers for detection of heat and nerve agents, photolithography and orthogonal photoswitching systems are discussed. Opening up: This Minireview provides an overview of the transformations involving Stenhouse salts and derivatives. Recent methods for the preparation of cyclopentenones and their applications namely in the synthesis of natural occurring products, polymers and photochromic systems are described.