Synthesis of one-pot pyrazolo[4′,3′:5,6]pyrano[2,3-<i>c</i>]phenazin-15-yl) methanone derivatives <i>via</i> a multi-component using Fe<sub>3</sub>O<sub>4</sub>@TiO<sub>2</sub>-SO<sub>3</sub>H as a recoverable magnetic catalyst under microwave irradiation
Green chemistry letters and reviews