One-Pot Cascade Access to Ru(II)-Catalyzed Regioselective C(sp2)-H Activation/Alkenylation of Chromeno[4,3-c]pyrazol-4-ones and Their Emission Solvatochromic Studies.

Abstract

Herein, one-pot cascade synthesis of chromeno[4,3-c]pyrazol-4-ones and their Ru(II)-catalyzed regioselective ortho-alkenylation using imine as a weak directing group are done with moderate to good yields. The reaction proceeds through a three-step domino process during which intermediates are also isolated in excellent yields. In addition, this methodology generates a number of interesting fluorophores with donor and acceptor groups, which show positive solvatochromism.