克莱门森还原反应合集.pdf

齐尔普医药化工 www trinup 齐尔普医药化工 www trinup 内部资料 克莱门森还原反应合集 NameNameNameName ReactionsReactionsReactionsReactions RecentRecentRecentRecent LiteratureLiteratureLiteratureLiterature In the presence of Co PPh3 2I2 PPh3 water and zinc powder the reductive coupling of alkynes with alkenes having an electron withdrawing substituent proceeded smoothly in acetonitrile to give the corresponding reductive coupling products in fair to excellent yields Possible mechanisms for this highly regio and stereoselective ene yne reaction are proposed C C Wang P S Lin C H Cheng J Am Chem Soc 2002200220022002 124 9696 9697 Zn Mediated Pd Catalyzed Cross Couplings in Water at Room Temperature Without Prior Formation of Organozinc Reagents A Kraskovskiy C Duplais B H Lipshutz J Am Chem Soc 2009200920092009 131 15592 15593 The efficient olefination from organozinc reagents with aldehydes is exploited 齐尔普医药化工 www trinup 齐尔普医药化工 www trinup 内部资料 in a new synthesis of aryl and alkyl olefins J X Wang Y Fu Y Hu K Wang Synthesis 2003200320032003 1506 1510 A Mannich like zinc mediated three component reaction of aromatic halides amines and paraformaldehyde allows the straightforward synthesis of a range of functionalized tertiary benzylamines This procedure involves the in situ formation of arylzinc reagents E Le Gall A Decompte T Martens M Troupel Synthesis 2010201020102010 249 254 A straightforward three component reaction of preformed aromatic or in situ generated benzylic organozinc reagents with amines and ethyl glyoxylate allows the synthesis of a range of amino esters in very good yields The procedure which is characterized by its simplicity allows the concise synthesis of esters bearing a phenylglycine or a phenylalanine scaffold C Haurena E Le Gall S Sengmany T Martens M Troupel J Org Chem 2010201020102010 75 2645 2650 In acetonitrile as solvent and in the presence of a simple cobalt halide as catalyst the reduction by zinc dust of a mixture of aldehydes or ketones and allylic acetates affords the corresponding homoallylic alcohols in good yields P Gomes C Gosmini J Prichon Synthesis 2003200320032003 1909 1915 A rapid and efficient procedure for the solvent free synthesis of homoallylic and homopropargyl alcohols has been achieved by zinc mediated Barbier type reaction of carbonyl compounds at room temperature J X Wang X Jia T Meng L Xin Synthesis 2005200520052005 2669 2672 齐尔普医药化工 www trinup 齐尔普医药化工 www trinup 内部资料 J X Wang X Jia T Meng L Xin Synthesis 2005200520052005 2669 2672 Titanocene dichloride catalyzes the formation of an organozinc species via catalytic activation of allyl halides Nucleophilic addition to carbonyl derivatives provides the desired homoallylic alcohols in very good yields in short reaction times This discovery will have wide ranging applicability in the generation of highly reactive organometallic reagents L M Fleury B L Ashfeld Org Lett 2009200920092009 11 5670 5673 Zinc promoted reduction of 2 bromomethyl alkenoates derived from Baylis Hillman adducts gave E 2 methylacrylates in good yield and high stereoselectivity Synthesis of the male ant pheromone E 2 4 dimethyl 2 hexenoic acid was performed using this simple methodology L Fernandes A J Bortoluzzi M M Sa Tetrahedron 2004200420042004 60 9983 9989 An efficient cobalt catalyzed reductive coupling reaction of alkyl halides with alkenes bearing electron withdrawing groups in the presence of water and zinc powder in acetonitrile gave the corresponding Michael type addition products in high yields The mechanism is discussed P Shukla Y C Hsu C H Cheng J Org Chem 2006200620062006 71 655 658 Cobalt complex Zn systems effectively catalyze the reductive coupling of activated alkenes with alkynes in the presence of water to give substituted alkenes with very high regio and stereoselectivity in excellent yields 齐尔普医药化工 www trinup 齐尔普医药化工 www trinup 内部资料 H T Chang T T Jayanth C C Wang C H Cheng J Am Chem Soc 2007200720072007 129 12032 12041 A range of polysubstituted allylic zinc chlorides were obtained in good yield using a LiCl mediated zinc dust insertion in polysubstituted allylic chlorides A highly diastereoselective synthesis of homoallylic alcohols bearing up to two adjacent quaternary centers by the addition of polysubstituted allylic zinc reagents to carbonyl compounds H Ren G Dunet P Mayer P Knochel J Am Chem Soc 2007200720072007 129 5376 5377 A dizinc reagent which acts as an effective bidentate Lewis acid is easily prepared from diiodomethane and zinc powder K Nomura K Oshima S Matsubara Angew Chem Int Ed 2005200520052005 44 5860 5863 Efficient simple cheap and environmentally benign preparations of cyclopropanes were achieved One method is based on a 3 exo trig cyclisation of various electron deficient 2 iodoethyl substituted olefins with zinc powder in a mixture oft butyl alcohol and water and the other on a 3 exo tet cyclisation of various 1 3 dihalopropanes with zinc powder in ethanol D Sakuma H Togo Tetrahedron 2005200520052005 61 10138 10145 D Sakuma H Togo Tetrahedron 2005200520052005 61 10138 10145 齐尔普医药化工 www trinup 齐尔普医药化工 www trinup 内部资料 The CoI2 dppe catalyzed diastereoselective reductive 3 2 cycloaddition of allenes and enones gives cyclopentanols in very good yields in the presence of zinc zinc iodide and water H T Chang T T Jayanth C H Cheng J Am Chem Soc 2007200720072007 129 4166 4167 A zinc indium chloride mediated pinacol cross coupling reaction between aldehyde and unsaturated ketone in aqueous media gives 1 2 diols in good yields with up to 93 7 diastereoselectivity Y S Yang Z L Shen T P Loh Org Lett 2009200920092009 11 2213 2215 An efficient one pot procedure for the zinc mediated reduction of nitroarenes in the presence of chloroformates leads to the correspondingN O bisprotected hydroxylamines in good yield under ambient conditions in THF water mixtures Solvolysis of the bisprotected hydroxylamines with sodium methoxide at room temperature provides access to synthetically versatileN aryl N hydroxy carbamates in excellent yields A Porzelle M D Woodrow N C O Tomkinson Synlett 2009200920092009 798 802 Upon treatment with aqueous sodium hydroxide in DMF a range of chalcones underwent Michael addition reactions with nitroalkanes The resulting adducts were reduced in situ with Zn HCl aq to afford substituted 1 pyrrolines in high yields after a cyclization Y Liang D Dong Y Lu Y Wang W Pan Y Chai Q Liu Synthesis 2006200620062006 3301 3304 齐尔普医药化工 www trinup 齐尔普医药化工 www trinup 内部资料 A convenient and highly regioselective method allows the synthesis of 5 methylenepyrrolidinone derivatives from various nitriles and acrylamides via a cobalt catalyzed reductive coupling reaction A possible mechanism involves the formation of a cobaltaazacyclopentene intermediate from nitrile and acrylamide protonation keto amide cyclization and dehydration Y C Wong K Parthsarathy C H Cheng J Am Chem Soc 2009200920092009 131 18252 18253 An efficient an