Gold(I) Catalyzed Enyne Cycloisomerization - A Roadmap to Privileged Heterocyclic Scaffolds

Gold(I) catalyzed cycloisomerization reaction is one of the key transformations that remain underexplored to build molecular diversity and complexity. In this review, we summarize synthesis endeavors where enyne cycloisomerization chemistry was utilized to form structurally intriguing as well as biologically relevant heterocyclic scaffolds. To this goal, most of the efforts tend to exploit gold carbene type intermediates, often supporting a cyclopropane ring and transform them into new scaffolds. Various examples have been grouped together to highlight the role of presence or absence of external heteroatom nucleophiles in modulating reactive intermediates into novel molecular frameworks. The last section is devoted to the emerging role of gold(I) catalyzed cycloisomerization reactions in driving the divergent synthesis approaches wherein a common substrate can be transformed into distinct molecular scaffolds by merely varying reaction conditions or gold complexes.