CATALYTIC CARBONYLATION FOR MACROCYCLIC KETONE AND MACROLIDE SYNTHESIS

Carbon monoxide gas is the cheapest and most abundant one carbon source. Palladium-catalyzed carbonylative cross coupling has developed fast in the last decade. It has become a platform for synthesizing carbonyl-containing complex molecules. Macrolides and macrocyclic ketones are one of the most common structures in nature products. The delicate balance between constructional flexibility and certainty endowed their promising bioactivities. Herein will be discussed novel palladium-catalyzed carbonylation reactions and their excellent performance in synthesis of macrocycle structures.

The total synthesis of trans-resorcylide was finished in 7 steps (LLS), featuring a palladium-catalyzed macrocyclic Stille carbonylation to build the 12-membered macrocycle. Notably, while a cis-vinylstannane-containing precursor was applied, the palladium-catalyzed macrocyclic Stille carbonylation delivered a trans-enone-containing product.

An efficient enantioselective palladium-catalyzed carbonylative macrolactonization to 2,3-dienolides with wide functional group tolerance was developed, adding one more to the few reported cases of enantioselective lactonization. Overcoming the difficulties in supply of 2,3-dienolides promoted the further study of their chemical properties. Fast total syntheses of zearalane and norzearalane II were finished implementing 2,3-dienolides. Phosphine catalyzed divergent [3+2] and [2+4] cycloadditions of 2,3-dienolide and 2,3-pyrrolidinedione were investigated. A spontaneous [2+2] dimerization of 2-phenyl-2,3-dienyl-11-undecanolide was discovered and probed.