A new route to 10-membered ring analogues of neocarzinostatin chromophore

Palladium-Catalyzed Cross-Coupling Syntheses of Benzotriazolyl Enynes and a General Route to Enynyl Ketones and Alkynyl Ketones

“…Enynyl ketones are important intermediates in the syntheses of various natural products and their analogues. − Common routes to enynyl ketones are based on reactions of enynyl organometallic reagents (e.g., those of magnesium, , lithium, , copper, and silicon) with carboxylic acid chlorides, esters, or anhydrides. However, such reactions of enynyllithium or magnesium reagents with carboxylic acid derivatives are not always satisfactory .…”

“…The cuprous-catalyzed reaction of acid chlorides and enynes can afford enynyl ketones in good yields in the presence of triethylamine as the base, but this method is not applicable to primary acid chlorides, such as acetyl, propanoyl, and butanoyl chlorides, which react readily with triethylamine PDC, or Swern reagents in moderate yields: the alcohols were prepared through the palladium-catalyzed coupling reactions between vinyl bromides and 3-hydroxyalkynylstannanes. However, all of the aforementioned preparations of enynyl ketones show some problems in the availability of starting materials and/or lack of generality.…”