Palladium-Catalyzed Heck-type Domino Cyclization and Carboxylation to Synthesize Carboxylic Acids by Utilizing Chloroform as the Carbon Monoxide Source

A palladium-catalyzed
domino cyclization and carboxylation reaction
for synthesis of a variety of carboxylic acids was developed, where
chloroform was used as “carbon monoxide” source. The
in situ generated neopentylpalladium species by Heck cyclization was
efficiently trapped by dichlorocarbene to form a series of carboxylic
acids. It was found that in this type of domino reaction CHCl3 is a convenient and safe alternation for CO gas.