Gold-Catalyzed Heteroannulation\nof Anthranilic Acids\nwith Alkynes: Synthesis of 3,1-Benzoxazin-4-ones

We demonstrated a rapid and facile approach for the synthesis\nof\nvarious 3,1-benzoxazin-4-ones via a gold-catalyzed heteroannulation\nof readily available nonprotected anthranilic acids and simple aryl\nalkynes. Our preliminary mechanistic investigation indicated that\nthe double incorporation of alkynes into anthranilic acids occurs\nthrough the formation of bisenamine intermediates.