Solvent-free Synthesis Of Quinolines, Xanthenes And Bis(Indolyl)methanes Catalyzed By Recyclable Iron(Ⅲ) Triflat

Much attention is currently being focused on organic reactions promoted by iron.Compared to other metals, such as gold, silver and palladium, the high abundance ofiron salt in the earth makes them less costly and easily available as well as low toxic.Recently, excellent work of iron-catalyzed reactions have been reported. In thedissertation, we put our emphasis on the studies of transition metal iron-catalyzedreaction, which consists of four parts.The first part shows the concept of green chemistry, the advantages of ironcatalyst, the application of iron in organic chemistry, the innovation points andresearch methods.The second part involves a novel application of highly stable Fe(OTf)3as anefficient catalyst for carbon-carbon bond formation via the activation of a terminalalkyne C-H bond under solvent-free conditions. Notably, this protocol of greensynthesis, which produced quinolines from the reaction of amines, aldehydes andterminal aryl alkynes, shows attractive characteristics including concise one-potconditions, high atom economy, very limited energy consumption, and the sequentialcatalytic process requires only a catalytic (5mol%) amount of Fe(OTf)3with shortreaction periods (3h). Meanwhile, the catalyst was easily recovered from the reactionsystem and reused smoothly with only a little loss of activity.The third part introduces solvent-free synthesis of14-aryl-14H-dibenzo[a,j]xanthenes through one-pot condensation of β-naphthol andaldehydes catalyzed by recyclable and reusable Iron(III) triflate. Remarkably, thepresented method features less reaction time, excellent yield and simple experimentalprocedure.The forth part involves that iron(III) triflate is used as a reusable catalyst for thecondensation of indole with aldehydes and ketones to afford the correspondingbis(indolyl)methanes under solvent-free conditions in excellent yields. Many advances in the strategy of BIM synthesis include less time, high yield, reusability ofcatalyst, and lower catalytic loading as well as simplicity of the workup.