Studies on the synthesis of macrocyclic allenes by ring closing metathesis and Doering-Moore-Skattebol reaction

摘要

Several efficient synthetic approaches to allenic cyclophanes of the general structure 2/3, which are of interest as chiral ligands or host molecules, are described. The combination of the ruthenium-catalyzed ring-closing metathesis and the Doering-Moore-Skattebol (DMS) reaction using the Seyferth reagent PhHgCBr3 provided a straightforward access to the allenic cyclophane B. The macrocycles 13 and 17 with the allenic bridge between the aromatic units were also obtained efficiently by copper-promoted S(N)2′-substitution of propargylic acetates and ring-closing metathesis. Alternatively, macrocyclic allenes can be synthesized by ring-closing metathesis of α,ω-bisallenes, as was demonstrated by the formation of the products 20, 21, and 23. © Wiley-VCH Verlag GmbH & Co.