Comprehensive Strategies for the Synthesis of 1,3-Enyne Derivatives

Abstract The synthesis of 1,3-enyne has widespread appeal in organic synthesis due to their proven adaptability as intermediates in routes to compounds of significant biological and material interest. A variety of methods have been designed to formulate 1,3-enynes from diverse substrates, such as alkynes, 1,3-diynes, alkynyl-substituted cyclopropanes, and propargyl alcohols. This review covers the synthesis of 1,3-enynes utilizing the homo- and cross-coupling of alkynes, nucleophilic metal/acid-induced cyclopropane ring opening, and rearrangement/dehydration of propargyl alcohols. A key concern in procedures starting from alkynes and 1,3-diynes is the management of regio-, stereo-, and, where fitting, chemoselectivity. In contrast, in cyclopropyl ring opening nucleophile orientation determines the 1,3-enynes formed. Efficient methods for the broad and selective synthesis of 1,3-enynes are highlighted and specific examples are given to demonstrate the efficacy of these processes. 1 Introduction and Scope 2 Synthesis 2.1 Synthesis of 1,3-Enynes from Alkynes 2.1.1 Metal-Catalyzed Cross-Coupling/Additions of Alkynes with Alkenes or Vinyl or Aryl Halides 2.1.1.1 Palladium Catalysis 2.1.1.2 Rhodium Catalysis 2.1.1.3 Copper Catalysis 2.1.1.4 I ron Catalysis 2.1.1.5 Nickel Catalysis 2.1.1.6 Miscellaneous 2.2 Synthesis of Enynes from Propargyl Alcohols 2.3 Metal/Acid-Catalyzed Ring Opening of Cyclopropanes 3 Conclusion