Enabling Access to Diverse Bioactive Molecules Through Enyne Metathesis Concepts

This paper surveys recent advances in valorization of transition-metal-catalyzed enyne metathesis as key events in the total synthesis of naturally occurring compounds of biological and medicinal importance. Special attention is devoted to methodologies based on dienyne ring-closing metathesis (RCM) applied in tandem and sequential processes, on relay ring-closing metathesis (RRCM), ringrearrangement metathesis (RRM), enyne cross-metathesis (CM) and enyne skeletal bond reorganization, all proceeding under metalcarbenes (Ru or Mo alkylidenes) or metal-salts (Pd or Pt) catalysis. The high potential of these procedures in constructing versatile scaffolds as essential structural cores of a diversity of bioactive natural products is highlighted. Inventive functionalizations by nonmetathesis transformations intervening in the total synthesis of the targeted natural compounds, prior to (Michael addition, Wittig olefination, allylation etc.) or after (Diels-Alder cycloaddion, Heck and Suzuki-Miyaura reactions, Dess-Martin oxidation, dihydroxylation, epoxidation etc.) the pivotal metathesis step have also been included.