卡宾和氮烯.pptx

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,#,7.1,卡宾,定义：电中性的含二价碳的化合物称为卡宾。,Carbenes are,uncharged,electron deficient,molecular species,H,2,C:ROOCCH:PhCH:BrCH:,ClCH:Cl,2,C:Br,2,C:,H,2,C:,ROOCCH:PhCH:BrCH:ClCH:,Cl,2,C:Br,2,C:,母体卡宾,不活泼的卡宾,能量逐渐降低,卡宾是一种能瞬间存在但不能分离得到的活性中间体。,Singlet state:,electrophilic character,trigonal planar geometry,Triplet state:,diradical-like in nature,linear geometry,C,H,H,s,p,2,p,1,3,6,o,C,H,H,s,p,2,p,1,0,3,o,C,H,H,S,i,n,g,l,e,t,C,H,H,T,r,i,p,l,e,t,s,p,2,s,p,2,p,p,1,0,3,o,1,3,6,o,C,H,2,N,2,h,v,8,-,1,0,k,c,a,l,/,m,o,l,N,N,H,H,s,t,a,b,l,e,c,r,y,s,t,a,l,m,p,2,4,0,-,2,4,1,o,C,共轭作用使卡宾稳定性增加,Carbenes with ferrocenyl substituents,Journal of Organometallic Chemistry,Volume:617-618,January 15,2001,pp.28-38,共轭作用使卡宾稳定性增加,共轭作用使卡宾的性质改变,Is triplet bis(10-phenylanthracen-9-yl)carbene(1)really a geminate diradical?,J.Org.Chem.,68,(12),4819-4832,2003.,Carbenes with ferrocenyl substituents,Journal of Organometallic Chemistry,Volume:617-618,January 15,2001,pp.28-38,A Search for Carbene-Solvent Interactions Using Time-Resolved Infrared Spectroscopy,Org.Lett.,5,(8),1305-1307,2003.,J.Org.Chem.,68,(12),4819-4832,2003.,Singlet carbene or pnictonium ylide?(a)Breslow,(b)Wanzlick,(c)Arduengo,and(d)Bertrand carbenes.,J.Org.Chem.,68,(12),4819-4832,2003.,Formation Reactions of Carbenes,（,1,）,-,消除,HCCl,3,Cl,2,C:+HCl,t-BuOK(or KOH),t-BuOK,HCCl,3,t-BuOK,t-BuOH,Cl,2,C,-,:,Cl,低酸性溶剂,Cl,2,C:+Cl,-,Cl,2,C:+Cl,-,+CO,2,（,2,）,某类双键化合物的裂分,h,h,H,2,C:+CO,H,2,C:+N,2,卡宾的反应,反应物 反应物,单线态卡宾 三线态卡宾,sp,2,sp,以单线态参与反应,衰变,以三线态参与反应,Typical Carbene Reactions,Carbene Insertion/Addition Reactions,Mechanistic Aspects of Carbene Chemistry,（,1,）,对双键的加成反应,+CHBr,3,(CH,3,),3,COH,(CH,3,),3,COK,*1,*2,CH,2,=CH-CH=CH,2,+:CH,2,:CH,2,*3,CH,2,=C=CH,2,+:CH,2,:CH,2,主要用于对,C=C,的加成，制备环丙烷的衍生物，但对,C=O,、,C=N,、碳碳叁键的加成也有报道。,*4,+2:CH,2,*5,*6,+:CH,2,+:CHCOOC,2,H,5,Cu,C,H,C,l,3,t,-,B,u,O,K,C,C,l,2,C,C,l,2,C,H,B,r,3,t,-,B,u,O,K,C,B,r,2,C,B,r,2,d,i,b,r,o,m,o,c,a,r,b,e,n,d,i,c,h,l,o,r,i,c,a,r,b,e,n,bis(diisopropylamino)phosphino(trimethylsilyl)carbene,J.Org.Chem.,68,(20),7707-7710,2003.,（,2,）,对,C-H,键的插入反应,最活泼的卡宾：,CH,2,易发生插入反应,单线态卡宾的反应过程为,三线态卡宾的反应过程为,+:CH,2,+,CH,2,+,CH,3,+,CH,3,自旋转化,结合,CH,2,N,2,h,加成反应产物,+,+,+,插入反应产物,26%11%26%37%,（,3,）,重排,Ring Expansion of Chloro(phenyl)carbene(9),Photolysis of 3-chloro-3-phenyl-3,H,-diazirine(8)in Ar at 10 K generates matrix-isolated chloro(phenyl)carbene(9),J.Org.Chem.,68(12),4819-4832,2003.,（,4,）,二聚5,）,Triplet carbenes could give free radicals,C,H,2,C,H,3,C,H,3,C,H,3,C,H,2,C,H,3,4,类卡宾与碳碳双键的加成反应,定义：,类卡宾是一类在反应中能起卡宾作用的非卡宾类化合物。,最常用的类卡宾是,ICH,2,ZnI,。,制备,CH,2,I,2,+Zn(Cu),ICH,2,ZnI,类卡宾与碳碳双键加成反应的反应机理,乙醚,+,ZnI,2,无插入反应,*3 CH,2,=CH-C-CH,3,=,O,Zn/Cu,CH,2,I,2,+,CH,2,I,2,+Zn(Cu),H,2,O,回流,(56-58%),*1 CH,2,CH-COOCH,3,+CH,2,I,2,+Zn(Cu),*2,(50%),Diazo Compounds,Org.Lett.;,(Communication);2003,;,5,(9);1479-1482.,Structural Diversity in Pyridine-N-Functionalized Carbene Copper(I)Complexes,Organometallics,20,(10),2027-2031,2001.,Organometallics,21,(10),2101-2106,2002.,7.2,氮烯,Nitrenes,R,N,R,N,S,i,n,g,l,e,tT,r,i,p,l,e,t,Nitrenes are uncharged,electron deficient molecular species that contain a monovalent nitrogen atom surrounded by a sextet of electrons.,Singlet state:,electrophilic character,trigonal planar geometry,Triplet state:,diradical-like in nature,linear geometry,酰基氮烯,Formation Reactions of Nitrenes,Generation of Nitrenes,1.Elimination,2.Breakdow of Certain Double-Bond Compounds,Mechanistic Aspects of Nitrene Cycloaddition Reactions,Nitrene Cycloaddition Reactions,Nitrene Insertion Reactions,Evidence of Singlet Nitrene Alkyl C-H Insertion Selectivity,Reactions of Nitrenes,1.Insertion reactions,3.Rearrangements,2,.,Addition to C=C bonds,5.Dimerization,4.Abstraction,R,N,+,R,H,R,N,H,+,R,异氰酸酯,胺基甲酸,酰基氮宾,重排,C,O,O,E,t,N,H,2,N,H,2,C,O,N,H,N,H,2,N,a,N,O,2,H,C,l,C,O,N,N,N,C,O,N,-,N,2,N,C,O,H,2,O,N,H,2,惰性溶剂,-N,2,R,C,N,:,O,重排,Nitrenium ions,the nitrogen analogs of carbocations,