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Updated: Sep 20, 2025

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives
Published on: January 19, 2016
Sc(OTf)3/BF3·OEt2-Catalyzed Annulation of 3-Formylchromones with Functionalized Alkenes: Access to Diverse
Sabera Sultana1, Peter Yuosef M Rubio1, Hari Datta Khanal1
1School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea.
Abstract:
The Sc(OTf)3/BF3·OEt2-catalyzed annulation of 3-formylchromones with functionalized alkenes for the direct construction of 2-hydroxybenzophenones is described. Sc(OTf)3/BF3·OEt2 acts as a synergistic catalyst, providing rapid synthetic access to diversely and highly functionalized 2-hydroxybenzophenones. This reaction has excellent regio- and chemoselectivities and is suitable for late-stage functionalization. The reaction proceeds via [3 + 3] and [4 + 2] cycloaddition processes, through carbonyl-ene, Diels-Alder, or aldol-type reactions. Furthermore, this protocol tolerates the various functional groups present in natural terpenes and steroids.
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