Stereo- and Regioselective Synthesis of (E,E)-Dienes: Evolution from the Transition-Metal-Catalyzed Cross-Coupling to Titanium Alkoxide-Based Alkyne–Alkyne Reductive Coupling

Abstract

AbstractThe pursuit of step- and atom-economy in natural product and complex molecule syntheses continuously inspires the development of synthetic methodologies. In this context, to enable efficient synthesis of (E,E)-dienes as common structural subunits in natural products, our lab has established robust protocols based on modified Negishi cross-couplings and evolved them to more concise titanium-mediated alkyne–alkyne reductive coupling. In this review, we summarize the natural product synthesis driven methodology development and their applications in the total synthesis of complex molecules, focusing on the studies from our laboratory.1 Introduction2 Transition-Metal-Catalyzed Cross-Coupling in Natural Product Synthesis2.1 Synthesis of Branched Trisubstituted Conjugated Dienes by Negishi Coupling2.2 Stereo- and Regiocontrolled Synthesis of Branched Trisubstituted Conjugated Dienes by Modified Negishi Coupling2.3 Enantioselective Total Synthesis of Reveromycin B by Drouet & Theodorakis2.4 Enantioselective Synthesis of the Protein Phosphatase Inhibitor (–)-Motuporin by Hu & Panek2.5 Total Synthesis of (–)-Callystatin A by Langille & Panek2.6 Total Synthesis of Brevisamide by Lee & Panek3 Titanium Alkoxide-Mediated Reductive Coupling in Natural Product Synthesis3.1 Titanium Alkoxide-Mediated Alkyne–Alkyne Reductive Coupling3.2 Total Synthesis of Callystatin A by Reichard & Micalizio3.3 Total Synthesis of (–)-Virginiamycin M2 by Wu & Panek3.4 Total Synthesis of Nuclear Factor of Activated T-Cells-68 (NFAT-68) by Cai & Panek3.5 Titanium Alkoxide-Based Regioselective Alkyne–Alkyne Reductive Coupling Mediated by in situ Generated Arylamidate4 Summary