استفاده از كاتاليزورهاي سبز روي و پالاديم در سنتز a- آمينونيتريل ها و بي فنيل ها

چكيده انگليسي :

Application of Zinc and Palladium as Green Catalysts in Synthesis of Amino Nitriles and Biphenyls Ifa Mahboobi Dehbane ifa mahboobi 65@yahoo com Octber 2 2010 Department of Chemistry Isfahan University of Technology 84156 83111 Isfahan IranProf A R Hajipour Email haji@cc iut ac irAbstractDue to the development of green chemistry in recent years researchers have been interested in the application ofionic liquids instead of common organic solvents Ionic liquids can also apply as green catalysts Ionic liquid haveremarkable properties such as non flammable high thermal stability negligible vapor pressure easy recyclabilityand high solvating ability In recent years ionic liquids containing Choline chloride as an inexpensive andbiodegradable compound have attracted a lot of attentions One pot multi component reactions due to their simpleand mild reaction condition energy saving and environmental compatibility are very important in carbon carbon andcarbon heteroatom bond formation Researches in organic chemistry have expanded the one pot multi componentreactions according to green chemistry purposes Solid state or solvent free reactions are called green or cleanreactions because organic solvents are not used in these reactions amino nitriles are important intermediates forthe preparation of many amino acids and various nitrogen containing heterocycles and other pharmacologicallyuseful molecules Because of their wide range of applications these compounds have received a great deal ofattention in recent years in connection with their synthesis Among various methods reported in the literature for thepreparation of amino nitriles the most important route for the synthesis of them is the Strecker reaction In thisreaction amino nitriles are synthesized by three component condensation of carbonyl compounds aldehydes orketones amine and a cyanid source Due to many vast application of C C bond formation in the areas including bioactive compounds natural productsand high performance materials over the past few years the C C coupling reactions have become a versatile tool inorganic synthesis The cross coupling of aryl halides with arylboronicacids namely Suzuki Miyaura couplingreaction has become one of the most powerful versatile and popular tools for the selective construction of carbon carbon bonds The fact that the products of this reaction are biaryls which are important structural moieties innumerous polymers agrochemicals natural products and pharmaceutical intermediates has made it an important andcommon tool in organic synthesis In the past two decades efforts have been made to develop efficient catalyticsystems for the Suzuki Miyaura coupling reaction Herein we synthesized an inexpensive and biodegradable Lewis acidic ionic liquid using Choline chloride andZnCl2 and then we applied it in synthesis of amino nitriles In this reaction various aldehydes and ketones werereacted with aniline and trimethylsilylcyanide TMSCN to afford the corresponding amino nitriles in high yields The advantage of this ionic liquid was its application for acid sensitive heterocycles which yielded thecorresponding amino nitriles without any polymerization In the next section an efficient and effective palladium salt was synthesized using the salt of 1 benzyl 4 aza 1 azoniabicyclo 2 2 2 octane chloride n benzyl DABCO chloride and palladium chloride This palladium salt wasapplied in Suzuki reaction as the catalyst In this reaction various aryl iodides and aryl bromides were coupled witharylboronic acids at room temperature and in ethanol as a green solvent and in the presence of K 2CO3 as the base Afterwards by changing the reaction condition and adding tetrabutylammonium bromide the palladium salt wasapplied in the synthesis of biphenyls from aryl chlorides which are cheaper and more available The appliedpalladium salt was oxygen resistant so all reactions were performed under air atmosphere Keywords Choline chloride amino nitriles trimethylsilylcyanide Suzuk

محبوبي دهبنه، ايفا

استفاده از كاتاليزورهاي سبز روي و پالاديم در سنتز a- آمينونيتريل ها و بي فنيل ها

كولين كلريد , تري متيل سايليل سيانيد , واكنش سوزوكي , n- بنزيل دابكوكلريد , تترابوتيل آمونيوم بروميد