14959-78-5Relevant academic research and scientific papers
Nucleophilic cyclization of o-alkynylbenzamides promoted by iron(III) chloride and diorganyl dichalcogenides: Synthesis of 4-organochalcogenyl-1H-isochromen-1-imines
Neto, Jose S.S.,Back, Davi F.,Zeni, Gilson
, p. 1583 - 1590 (2015)
We have developed a method for the preparation 4-organochalcogenyl-1H-isochromen-1-imines from o-alkynylbenzamides. This electrophile-promoted nucleophilic cyclization achieved by treatment with a combination of iron salts and diorganyl dichalcogenides. FeCl3 and diorganyl dichalcogenides reacted with o-alkynylbenzamides under aerobic conditions at room temperature and in the absence of additives to give 4-organochalcogenyl-1H-isochromen-1-imines in good yields and with good selectivities. The reaction took place with 0.5 equiv. of the diorganyl dichalcogenides, which demonstrates that both halves of the diorganyl dichalcogenides (RYYR → 2RY) were incorporated into the final product. Mechanistic studies suggested that the regioselectivity of the cyclization is governed by a seleniranium ion, a key intermediate formed by the electrophilic addition of the organochalcogen moiety to the carbon-carbon triple bond. The utility of the 4-organochalcogenyl-1H-isochromen-1-imines was also demonstrated by their application as starting materials in Suzuki and Sonogashira cross-coupling reactions.
1-Azidoisochromenes. A New Route to 3,1-benzoxazepines
Le Roux, Jean-Pierre,Desbene, Paul-Louis,Cherton, Jean-Claude
, p. 847 - 849 (2007/10/02)
Nucleophilic attack of sodium azide on isochromylium salts leads to the preparation of 1-azidoisochromenes which when heated lose molecular nitrogen and give 3,1-benzoxazepines.
