كاربرد كمپلكس هاي اورتوپالاديت در سنتز و شناسايي محصول واكنش هاي هك، سوزوكي، سيانيددار كردن و هموكوپلينگ

چكيده انگليسي :

Application of orthopalladated complexes in the Heck Suzuki Homocoupling Reactions and cyanation of Aryl halides Ghazal Tavakoli Gheinani kimiagar iut@yahoo com Octber 2 2010 Department of Chemistry Isfahan University of Technology 84156 83111 Isfahan Iran Prof A R Hajipour Email haji@cc iut ac ir Isfahan University of Technology 84156 83111 Isfahan Iran Abstract Due to many vast application of C C bond formation in the areas including bioactive compounds natural products and high performance materials over the past few years the C C coupling reactions have become a versatile tool in organic synthesis Some of the most efficient methods in this category are Heck Suzuki homocoupling and cyanation of aryl halides These reactions often performed under elevated temperature therefore all of the reaction partners should have high thermal stability Palladacycles can be defined as heterocyclic compounds that one of their heteroatoms in their structures is palladium In the recent years these compounds have found variable applications in the synthesis of organic compounds and formation of new C C bonds as catalyst Application of microwave irradiation for promoting reaction condition nowadays has become a versatile tool in organic synthesis This technique can cause to increasing the yields of reactions decrease the required time for completion of the reactions and also has advantage for enabling reproducible and scalable chemistry development in research laboratories and industrial processes In spite of traditional heating conditions that transferred the heat through the reaction vessel in this procedure heat transfer occurs in a direct manner and reaction mixture absorbs the microwave irradiation directly cause to saving time and energy Herein the application of four different palladacycle systems as pre catalyst in the formation of C C bonds were examined under microwave irradiation and their results were compared with reactions under conventional heating conditions in an oil bath Primarily the activity of Pd C6H4CH2NH2 2 C N PPh3MOBPPY OTf complex 1 MOBPPY 4 methoxybenzoylmethylenetriphenylphosphoraneylide was investigated in the Heck Mizoroki reaction under conventional heating and microwave irradiation conditions The complex was active and efficient catalyst for the Heck reaction of aryl halides The yields were excellent using a catalytic amount of complex 1 in NMP at 130 C In comparison to conventional heating conditions the reactions under microwave irradiation gave higher yields in shorter reaction time Also application of this catalyst in the homocoupling reaction of various types of aryl halides was examined under MW irradiation and optimized reaction condition Again the complex was active and showed high efficiency in the formation of new C C bonds The reactions were carried out using DMF as solvent and 0 1 mol of catalyst at 120 oC Then we used four different palladacycles 1 4 in the cyanation reaction of aryl halides under MW irradiation and compared their results with each other Reactions were performed using K4 Fe CN 6 as cyanating agent in DMF as optimized solvent and 0 5 mol of palladacycles at 130 oC The resulted yields were very good to excellent and the required time for completion the reactions is very short Finally we investigated the application of palladacycle complex 3 in the Suzuki cross coupling reaction of aryl halides using phenyl boronic acid under microwave irradiation condition Again the reaction conditions were optimized and NMP as the best solvent 0 1 mol of palladacycle complex 3 as the best concentration of catalyst and K2CO3 as the best base were chosen The resulted yields in this case were very good to excellent and the reaction times were reduced from hours to minutes using microwave irradiation Keywords Orthopalladate catalyst Heck K4 Fe CN 6 cyanation reaction Suzuki homocopling reaction

توكلي ، غزال

كاربرد كمپلكس هاي اورتوپالاديت در سنتز و شناسايي محصول واكنش هاي هك، سوزوكي، سيانيددار كردن و هموكوپلينگ

كاتاليزور , [(k4[Fe(cN6