Convergent strategies for the total synthesis of polycyclic ether marine metabolites

Marine polycyclic ether natural products continue to fascinate chemists and biologists due to their exceptionally large and complex molecular architectures and potent and diverse biological activities. Tremendous progress has been made over the past decade toward the total synthesis of marine polycyclic ether natural products. In this area, a convergent strategy for assembling small fragments into an entire molecule always plays a key role in successful total synthesis. This review describes our efforts to develop convergent strategies for the synthesis of polycyclic ethers and their application to the total synthesis of gambierol, gymnocin-A, and brevenal, and to the partial synthesis of the central part of ciguatoxins and the nonacyclic polyether skeleton of gambieric acids.

Strategies for the Synthesis of 2-Substituted Indoles and Indolines Starting from Acyclic α-Phosphoryloxy Enecarbamates

Strategies have been developed for the synthesis of 2-substituted indoles and indolines starting from acyclic alpha-phosphoryloxy enecarbamates. A highly chemoselective cross-coupling of N-(o-bromophenyl)-alpha-phosphoryloxyenecarbamates with boron nucleophiles enabled the efficient preparation of various N-(o-bromophenyl)enecarbamates, which served as useful precursors for subsequent Heck-type cyclization or 5-endo-trig aryl radical cyclization to furnish 2-substituted indoles or indolines, respectively.

A new method for the generation of indole-2,3-quinodimethanes and 2-(N-alkoxycarbonylamino)-1,3-dienes. Intramolecular Heck/Diels-Alder cycloaddition cascade starting from acyclic alpha-phosphoryloxy [corrected] enecarbamates

An intramolecular Heck/Diels-Alder cycloaddition cascade starting from acyclic alpha-phosphono enecarbamates has been developed to prepare nitrogen heterocycles via indole-2,3-quinodimethanes and 2-(N-alkoxycarbonylamino)-1,3-dienes.

An efficient method for the synthesis of enol ethers and enecarbamates. Total syntheses of isoindolobenzazepine alkaloids, lennoxamine and chilenine

An efficient method for the synthesis of enol ethers and enecarbamates has been developed based on catalytic hydrosilane reduction of alpha-phosphonoxy enol ethers and alpha-phosphonoxy enecarbamates. This method has been applied to the total syntheses of two isoindolobenzazepine alkaloids, lennoxamine and chilenine.