The first examples of CS induced PausonâKhand type reactions are described; 2-alkynylphenyl isothiocyanates were converted to 3-substituted-2H-thieno[2,3-b]indol-2-ones in the presence of a stoichiometric amount of Mo(CO)6 or Co2(CO)8, or a catalytic amount of Rh catalyst under an atmospheric pressure of carbon monoxide.
Triflic acid-promoted cycloisomerization of 2-alkynylphenyl isothiocyanates and isocyanates: a novel synthetic method for a variety of indole derivatives
A new approach towards the synthesis of indolederivatives via triflic acid-promoted cycloisomerization with rearrangement of 2-(alkyn-1-yl)phenylisothiocyanates and 2-(alkyn-1-yl)phenylisocyanates has been achieved. By this methodology, structurally diverse types of indolederivatives such as thieno- and furo-indoles, spiro-indolethiones, spiro-oxindoles, and 3-alkylidene-oxindoles were synthesized