高等有机化学碳杂重键的加成反应-PPT.pptx

高等有机化学碳杂重键的加成反应peted procedure:SubstitutionStep 3、Step 4、Step 2、Step 1、When A,B are H,R,Ar,the substrate is an aldehyde or ketone,these almost undergo addition!For carboxylic acids and their derivatives (B=OH,OR,NH2,X,etc),the substitution is major procedure!ActivityElectronic effectCCl3-CH=O +HOHCCl3-CH(OH)2Steric effectNucleophilicityStereochemistry+LiAlH4 88%12%LiAl(s-BuO)3H 7%93%etherLiAlH4H2O+75%25%Aldol condensationBase-catalyzed-H+-H2O烯醇化烯醇化亲核加成亲核加成H+-H+Acid-catalyzedClaisen-Schemidt reactionH2O-C2H5OHNaOH88%-93%Thorpe Reaction10大家应该也有点累了,稍作休息大家有疑问得大家有疑问得大家有疑问得大家有疑问得,可以询问与交流可以询问与交流可以询问与交流可以询问与交流Knoevenagel reactioneg 1、eg 2、eg 3、制备各种类型得制备各种类型得,-不饱与化合物、不饱与化合物、Mannich reactionPrimary or secondary amineActive hydrogen pounds H+转移转移 Acid catalyzed制备制备,-不不饱饱与与醛酮醛酮Wittg reactionYlidePh3P +CH3XPh3P+-CH3X-C6H5LiPh3P+-CH2-Ph3P +XCH2COOC2H5Ph3P+-CH2COOC2H5 X-K2CO3Mechanism内鏻盐内鏻盐Reformatsky ReactionDarzens Reaction,-环氧酸酯环氧酸酯*CH2 生成醛生成醛 CHR 生成酮生成酮H+Mechanism-CO2Benzoin Condensation安息香安息香X、Linghu,J、S、Johnson,Angew、Chem、,2003,115,2638Key Intermediate:二苯乙醇酸重排二苯乙醇酸重排acceptor(donor)donor(acceptor)Cannizzaro Reaction(Disproportionation)NaOH C2H5OH50oC+H+反应机理反应机理交错的交错的Cannizzaro 反应：反应：季戊四醇季戊四醇羧酸衍生物与亲核试剂得反应羧酸衍生物与亲核试剂得反应减小减小反应活性反应活性:加成加成-消除历程消除历程酯得水解酯得水解BAC2Or H+R具有手性时具有手性时,构型保持构型保持AAC2AAL1R具有手性时具有手性时,外消旋化外消旋化Claisen Condensation