Applications of the Horner-Wadsworth-Emmons Olefination in Modern Natural Product Synthesis

The Horner-Wadsworth-Emmons (HWE) reaction is one of the most reliable olefination reaction and can be broadly applied in organic chemistry and natural product synthesis with excellent selectivity. Within the last few years HWE reaction conditions have been optimized and new reagents developed to overcome challenges in the total syntheses of natural products. This review highlights the application of HWE olefinations in total syntheses of structurally different natural products covering 2015 to 2020. Applied HWE reagents and reactions conditions are highlighted to support future synthetic approaches and serve as guideline to find the best HWE conditions for the most complicated natural products. 1 Introduction and Historical Background 2 Applications of HWE 2.1 Cyclization by HWE Reactions 2.2.1 Formation of Medium- to Larger-Sized Rings 2.2.2 Formation of Small- to Medium-Sized Rings 2.3 Synthesis of alpha,beta-Unsaturated Carbonyl Groups 2.4 Synthesis of Substituted C=C Bonds 2.5 Late-Stage Modifications by HWE Reactions 2.6 HWE Reactions on Solid Supports 2.7 Synthesis of Poly-Conjugated C=C Bonds 2.8 HWE-Mediated Coupling of Larger Building Blocks 2.9 Miscellaneous 3 Summary and Outlook

Automated summary

The Horner-Wadsworth-Emmons (HWE) reaction is a reliable olefination reaction widely used in organic chemistry and natural product synthesis, with excellent selectivity. This review summarizes the application of HWE olefinations in total syntheses of structurally different natural products, serving as a guideline for future synthetic approaches.