Heterocycles from Alkylidenecyclopropanes

Heterocyclic compounds, which represent almost two-thirds of all the known organic compounds, include some of the most significant for human beings. It is not surprising, therefore, that this class of compounds has received special attention by chemists of different origin to provide selective synthetic access to the enormous variety of structural features typical of this class. The scope of this review is to collect and analyze the methods that make use of strained alkylidenecyclopropanes1 (ACPs) 1 to produce heterocyclic compounds. Doing this, we are confident of making a useful contribution to the organic chemistry community because, despite the huge literature already available on these rather sophisticated olefins, their employment in the synthesis of heterocyclic compounds has been only barely examined before and it is time to propose a comprehensive review that will present the state of the art.