Regioselective cobalt(II)-catalyzed [2 + 3] cycloaddition reaction of fluoroalkylated alkynes with 2-formylphenylboronic acids: easy access to 2-fluoroalkylated indenols

Tatsuya Kumon; Miroku Shimada; Jianyan Wu; Shigeyuki Yamada; Tsutomu Konno

doi:10.3762/bjoc.16.184

Regioselective cobalt(II)-catalyzed [2 + 3] cycloaddition reaction of fluoroalkylated alkynes with 2-formylphenylboronic acids: easy access to 2-fluoroalkylated indenols

Beilstein J Org Chem. 2020 Sep 4:16:2193-2200. doi: 10.3762/bjoc.16.184. eCollection 2020.

Authors

Tatsuya Kumon¹, Miroku Shimada¹, Jianyan Wu¹, Shigeyuki Yamada¹, Tsutomu Konno¹

Affiliation

¹ Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.

Abstract

[2 + 3] cycloaddition reactions of fluorinated alkynes with 2-formylphenylboronic acids under the influence of Co(acac)₂·2H₂O in two-component solvents of acetonitrile/2-propanol at reflux temperature for 18 h took place smoothly, affording the corresponding fluoroalkylated indenol derivatives in good yields. This reaction shows excellent regioselectivity, giving 2-fluoroalkylated indenols, together with a very small amount of 3-fluoroalkylated indanones as side products.

Keywords: [2 + 3] cycloaddition; cobalt catalyst; fluorine-containing; indenols; regioselective.