Synthesis Of 1-aryl-4,4,4-trifluorobutan-1-ones And(E)-2-aryl-1,1,1-trifluorobutan-2-enes

Due to the strong electronegativity of fluorine atoms,fluorine-containing compounds have unique physical and chemical properties and physiological activities.Therefore,fluorinated compounds are widely used in the fields of pharmaceuticals,pesticides and materials.In the process of new drug development,the introduction of fluorine atoms into active compounds can effectively improve the stability of the drug in the biological body,liposolubility and bioavailability.Hence,the research on synthetic methodology of fluorinated compounds has attracted wide attention.Trifluoromethyl ketones and trifluoromethyl butanes are important fluorinated compounds,which play an important role in the synthesis of liposolubility molecules and high performance materials.In the previous study,a series(Z)-trifluoromethylated alkenyl triflates of functional groups were synthesized by two steps and one-pot method,and successfully applied to the synthesis of various fluorinated compounds.On the basis of the previous studies,(Z)-trifluoromethylated alkenyl triflates was further applied to the synthesis of 1-aryl-4,4,4-trifluorobutan-1-one under the promotion of base.Furthermore,the base-free Suzuki coupling was carried out with palladium acetate as catalysts.The specific work is as follows.1)The 1-aryl-4,4,4-trifluorobutan-1-one was synthesized from a series of(Z)-trifluoromethylated alkenyl triflates-under the promotion of DBU.This method is easy to operate,good selectivity,wide applicability,and easy separation,and the separation yield is up to 98%.At the same time,it avoids the use of expensive and toxic metal catalysts,and provides a new method for synthesizing the ?-trifluoromethyl ketones.2)The Suzuki coupling reaction of(Z)-trifluoromethylated alkenyl triflates with aryl boronic acids was carried out using palladium acetate as catalysts,triphenylphosphine as ligand and without extra alkali.It is an efficient method to afford(E)-2-aryl-1,1,1-trifluorobutan-2-enes.The functional groups,such as halogen,alkoxy,heterocycle,condensed ring,and alkyl were all tolerated well,and the yield was up to 99%.