AbstractIntramolecular hydroarylation using aryl alkynylphosphonates proceeds smoothly with a gold/silver catalyst in the presence of trifluoromethanesulfonic acid (TfOH) in the 6‐endo mode, thus affording a unique synthetic method for phosphacoumarins having various functional groups, which could be a privileged structure and prevalent scaffold in phosphorus heterocycles.magnified image
Phosphine/Palladium-Catalyzed Syntheses of Alkylidene Phthalans, 3-Deoxyisoochracinic Acid, Isoochracinic Acid, and Isoochracinol
摘要:
In this study we used sequential catalysis-PPh3-catalyzed nucleophilic addition followed by Pd(0)-catalyzed Heck cyclization-to construct complex functionalized alkylidene phthalans rapidly, in high yields, and with good stereoselectivities (E/Z ratios of up to 1:22). The scope of this Michael-Heck reaction includes substrates bearing various substituents around the alkylidene phthalan backbone. Applying this efficient sequential catalysis, we accomplished concise total syntheses of 3-deoxyisoochacinic acid, isoochracinic acid, and isoochracinol.