A palladium-catalyzed approach to allenic aromatic ethers and first total synthesis of terricollene A

A palladium-catalyzed C-O bond formation reaction between phenols and allenylic carbonates to give 2,3-allenic aromatic ethers with decent to excellent yields under mild reaction conditions has been described. A variety of synthetically useful functional groups are tolerated and the synthetic utility of this method has been demonstrated through a series of transformations of the allene moiety. By applying this reaction as the key step, the total syntheses of naturally occurring allenic aromatic ethers, eucalyptene and terricollene A (first synthesis; 4.5 g gram scale), have been accomplished.

Automated summary

A palladium-catalyzed C-O bond formation reaction between phenols and allenylic carbonates has been developed, yielding 2,3-allenic aromatic ethers with good to excellent yields under mild conditions. This method tolerates various functional groups and has been demonstrated to be synthetically useful through transformations of the allene moiety. Total syntheses of naturally occurring allenic aromatic ethers, eucalyptene and terricollene A, have been achieved by utilizing this reaction as a key step.