资源描述
,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,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,单击此处编辑母版标题样式,*,Protecting Groups in Organic Synthesis,Protecting Groups in Organic,选择保护基的原则:,(1),保护基的供应来源,包括经济程度。,(2),保护基团必须能容易进行保护,且保护效率高。,(3),保护基的引入对化合物的结构论证不致增加过量的复杂性,如保护中忌讳产生新的手性中心。,(4),保护以后的化合物必须承受的起以后进行的反应和后处理过程。,(5),保护基以后的化合物对分离、纯化、各种层析技术要稳定。,(6),保护基团在高度专一的条件下能选择性、高效率地被除去。,(7),去保护过程的副产物和产物能容易被分离。,呼之即来,挥之即去。,切莫请神容易,送神难。,选择保护基的原则:(1)保护基的供应来源,包括经济程度。,羟基的保护基,1).,酯类保护基,t,-BuCO(Pivalyl,新戊酰基,;Piv);PhCO;MeCO;ClCH,2,CO,et al.,90%,Nicolaou,K.C.;Webber,S.E.,Synthesis,1986,453,羟基的保护基1).酯类保护基,酯类保护基的除去,(cleavage),碱性条件下水解,水解能力:,t,-BuCO(Piv)PhCO MeCO ClCH,2,CO,常用的碱:,K,2,CO,3,NH,3,NH,2,NH,2,Et,3,N,i,-Pr,2,NEt et al,去除,Piv,一般用较强的强碱体系,如,KOH/H,2,O,LiAlH,4,DIBAL,KBH(OEt),3,酯类保护基的除去(cleavage),ClCH,2,CO,的去除可以用硫脲,氨,/,甲醇,苯,吡啶水溶液,,NH,2,CH,2,CH,2,SH,NH,2,CH,2,CH,2,NH,2,PhNHCH,2,CH,2,NH,2,等除去。,ClCH2CO的去除可以用硫脲,氨/甲醇,苯,吡啶水溶液,N,有机合成中的保护基ppt课件,2).,硅醚保护基,硅醚保护基主要有:,Me,3,Si (trimethylsilyl,TMS);,Et,3,Si (triethylsilyl,TES);,t,-BuMe,2,Si(,tert,-butyldimethylsilyl,TBDMS or TBS),i,-Pr,3,Si (triisopropylsilyl,TIPS),t,-BuPh,2,Si (,tert,-butyldiphenylsilyl,TBDPS),酸水解相对稳定性,:,TMS(1)TES(64)TBDMS(20,000)TIPS(700,000)TBDPS(5,000,000),碱水解相对稳定性,:,TMS(1)TES(50)TBDMS=TBDPS(20,000)TIPS(100,000),硅醚保护基的除去:(,F-Si 142 kcal/mol;O-Si 112 kcal/mol,),通常用,HF/CH,3,CN;TBAF/THF;HF.Py/CH,3,CN,2).硅醚保护基,TMS ether,:,TMSCl or TMSOTf in pyridine,NEt,3,i,-Pr,2,NEt,imidazole,DBU,TMS ether:TMSCl or TMSOTf in,TES ether,:,TESCl/Imid.DMAP;TESOTf/Py.or 2,6-dimethylpyridine(2,6-lutidine),TES ether:TESCl/Imid.DMAP;T,TBDMS ether,:,TBDMSCl/imid./DMF;TBDMSOTf /2,6-lutidine,TBDMS ether:TBDMSCl/imid./,TBDPS ether,:,TBDPSCl/imidazole/DMF,catalyst:DMAP,solvent:CH,2,Cl,2,TBDPS ether:TBDPSCl/imidazo,TIPS ether,:,TIPSCl/DMF/imidazole.,TIPS ether:TIPSCl/DMF/imi,Cleavage,Cleavage,Cleavage,Cleavage,C,l,eavage,Cleavage,Cleavage,Cleavage,cleavage,烷基醚类:,Me(,甲基醚,),reagent:MeI;(MeO),2,SO,2,;MeOTf,cleavage:TMSI/CH,3,Cl(CH,2,Cl,2,or MeCN)or BBr,3,/CH,2,Cl,2,Bn(,苄基醚,),reagent:PhCH,2,Br or PhCH,2,Cl,cleavage:H,2,/10%Pd/C,Raney-Ni,Rh-Al,2,O,3,;Li(Na)/NH,3,PMB(,对甲氧基苄基醚,);DMB or DMPB(3,4-,二甲氧基苄基醚,),reagent:PMBCl;p-MeOC,6,H,4,CH,2,O-C(=NH)CCl,3,cleavage:DDQ,CAN,Tr(,三苯甲基醚,),reagent:TrCl/Py/DMAP;TrOTf/2,6-lutidine,claevage:HCO,2,H-H,2,O;HCO,2,H-,t,-BuOH;HCl/MeCN;Na/NH,3,tert,-butyl(,叔丁基醚,),reagent:isobutene/CH,2,Cl,2,;,t,-BuO-C(=NH)CCl,3,cleavage:HCO,2,H;CF,3,CO,2,H;HBr-HOAc,FeCl,3,;TiCl,4,;TMSI,allyl(,烯丙基醚,),reagent:Allyl bromide,cleavage:,t,-BuOK/DMSO/NaOH,烷基醚类:Me(甲基醚),烷氧基烷基醚:,MOM(,甲氧基甲基醚,),m,eth,o,xy,m,ethyl ether,MTM(,甲硫基甲基醚,),m,ethyl,t,hio,m,ethyl ether,MEM(,甲氧基乙氧基甲基醚,),m,ethoxy,e,thoxy,m,ethyl ether,BOM(,苄氧基甲基醚,),b,enzyl,o,xy,m,ethyl ether,SEM(,三甲硅基乙氧基甲基醚,)trimethyl,s,ilyl,e,thoxy,m,ethyl ether,reagents,:RCl or RBr/NaH/THF,cleavage,:MOM HCl/THF/H,2,O(1:2:1);Lewis acid:Me,3,SiBr/CH,2,Cl,2,;Me,2,BBr/CH,2,Cl,2,MTM AgNO,3,/2,6-lutidine;HgCl,2,/CaCO,3,MEM ZnBr,2,/CH,2,Cl,2,;HBr/THF;TiCl,4,/CH,2,Cl,2,;Me,2,BBr/CH,2,Cl,2,BOM Na/NH,3,/EtOH,H,2,/Pd(OH),2,/C;Raney-Ni/EtOH;,BF,3,/PhSH/CH,2,Cl,2,SEM HCl/MeOH;Lewis acid;,THP(,四氢吡喃,)tetrahydropyrane ether,reagents,:DHP(3,4-dihydro-2,H,-pyran),cleavage,:HOAc/THF/H,2,O(4:2:1),烷氧基烷基醚:MOM(甲氧基甲基醚)methoxymeth,O,O,-Acetals(,缩醛和缩酮),Reagents:,Acetone;benzaldehyde,cyclo-ketone,Cleavage:,Acid;Lewis acid,1,2,或,1,3-,二醇的保护:,O,O-Acetals(缩醛和缩酮)Reagents:1,2,醛酮的保护:,O,O,-acetals:,1,3-dioxalane(5-number ring)and 1,3-dioxane(6-number ring),Catalyst:,p,-TsOH,CSA,PPTs,醛酮的保护:O,O-acetals:,有机合成中的保护基ppt课件,Carboxylic acid,:,1)Methyl ester,Reagent:MeOH/HCl;MeOH/TMSCl;MeOH/SOCl,2,;MeI/KHCO,3,Cleavage:LiOH,KOH,NaOH/MeOH,THF,Carboxylic acid:1)Methyl este,Carboxylic acid 2,2),tert,-butyl ester,Reagent:iso,but,ene/H,2,SO,4,Cleavage:acetic acid/isopropanol;TFA/CH,2,Cl,2,Carboxylic acid 22)tert-butyl,Carboxylic acid 3,:,3)MOM(methoxymethyl),MEM(2-methoxyethoxymethyl),BOM (benzyloxymethyl),MTM(methylthiomethyl),SEM (2-trimethylsilyl ethoxymethyl),TCE(2,2,2-trichloroethyl),TMSE(2-trimethylsilylethyl),TsE (2-tosylethyl),Bn (benzyl),allyl(allyl)ester,Carboxylic acid 3:3)MOM(meth,Amino group 1,:,1)Boc(,tert,-butoxycarbonyl),Reagent:(Boc),2,O;,BocON(2-(,tert,-butoxycarbonyloxyimino)phenylacetonitrile),Cleavage:TFA;TFA/CH,2,Cl,2,Amino group 1:1)Boc(tert-but,有机合成中的保护基ppt课件,Amino group 2,2)Cbz(benzyloxycarbonyl)Bergman(1932),reagent:CbzCl/base,cleavage:catalytic hydrogenation,Amino group 22)Cbz(benzyloxy,Amino group 3,:,3)Fmoc(9-fluorenylmeth,ox,ycarbonyl),reagent:Fmoc-Cl/NaHCO,3,Cleavage:NH,3,Et,2,NH,piperidine,marpholine,Amino group 3:3)Fmoc(9-fluor,有机合成中的保护基ppt课件,
展开阅读全文