Dibenzocycloheptanones (dibenzotropones) were prepared by Brønsted acid mediated intramolecular alkyne-carbonyl metathesis (ACM) reactions. The cyclization precursors are readily available by Sonogashira reaction of 2-bromobenzoyl chloride with terminal alkynes, followed by Suzuki reactions with benzaldehydes. The ACM reactions are highly modular and atom economic and allow for the construction of two regioisomeric series of dibenzotropones.

Naphtho­thiophenes were prepared from commercially available 2,3-dibromo­thiophenes in two steps by one-pot Suzuki/Sonogashira or Sonogashira/Suzuki coupling reactions, followed by intramolecular alkyne-carbonyl-metathesis reactions. The final cyclization reaction proceeds in the presence of p-toluene­sulfonic acid and provides a rapid access to two series of isomeric naphtho­thiophenes.

Imidazo[1,2-a]benzoazepines were prepared in good yields by combination of Pd catalyzed cross coupling reactions with alkyne-carbonyl metathesis (ACM).

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The Stereoselective Synthesis of Tetrahydrothiopyrano[2,3-b]indole Skeletons via Tandem Reaction of Indoline-2-thiones to Baylis-Hillman Adduct Acetates. -(MOGHADDAM*, F. M.; FOROUSHANI, B. K.; SOBHANI, M.; MASOUD, N.; KHODABAKHSHI, M. R.; WENG, N. S.; Tetrahedron 69 (2013) 38, 8169-8173, http://dx.