A simple method for the preparation of arylnaphthalene lactone natural products was developed and used to synthesize diphyllin (10), justicidin A (12), cilinaphthalide B (13), taiwanin E (15), chinensinaphthol (16), taiwanin E methyl ether (17), chinensinaphthol methyl ether (18), justicidin C (21), and justicidin D (22). Key steps of the syntheses include the Hauser–Kraus annulation of cyanophthalides 7a and 7b and Suzuki–Miyaura cross‐coupling reactions between arylnaphthalene lactones that contain a sulfonate group (i.e., 9, 14, 19, and 20) and various potassium aryltrifluoroborates.

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Unsymmetrical diarylalkynes were synthesized in moderate to good yields through a three‐component one‐pot procedure involving thermocontrolled sequential Sonogashira reactions with potassium ethynyltrifluoroborate and two different reactive aryl halides. The one‐pot procedure was initiated by the palladium/copper‐catalyzed Sonogashira coupling of potassium ethynyltrifluoroborate to an aryl iodide or electron‐deficient aryl bromide at 40 °C. Following a subsequent deboronative Sonogashira reaction of the in situ generated potassium (arylethynyl)trifluoroborate, a second coupling to a less‐active electron‐rich aryl bromide at 80 °C, without any additional palladium/copper catalyst or base, gave rise to unsymmetrical diarylalkynes.