TheSakuraireaction(alsoknownastheHosomi–Sakuraireaction)isthechemicalreactionofcarbonelectrophiles(suchasaketoneshownhere)withallyltrimethylsilanecatalyzedbystrongLewisacids.Lewisacidactivationisessentialforcompletereaction.StrongLewisacidssuchastitaniumtetrachloride,borontrifluoride,tintetrachloride,andAlCl(Et)2arealleffectiveinpromotingtheHosomireaction.Thereactionisatypeofelectrophilicall...[
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First-generationGrubbscatalystItissynthesizedfromRuCl2(PPh3)3,phenyldiazomethane,andtricyclohexylphosphineinaone-potsynthesis.Second-generationcatalystThesecond-generationcatalysthasthesameusesinorganicsynthesisasthefirstgenerationcatalyst,butgenerallywithhigheractivity.Thiscatalystisstabletowardmoistureandair,thusiseasiertohandleinthelab.Hoveyda–GrubbscatalystsFirst-generationHoveyda–...[
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Formorethanahalfofacentury,BarryTrosthasbeenahighlyinfluentialscientistinalmosteveryaspectoforganicsynthesis,includingmethodologyandtotalsynthesis.Hestartedhiscareerataremarkablyyoungage.AfterobtaininghisB.Sc.degreeinchemistryfromtheUniversityofPennsylvania(1962),hemovedtoMITwherehecompletedhisPh.D.withH.O.House,workingonfundamentalaspectsofenolatechemistry.Remarkably,attheageof24,immediatelyafter...[
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TheShiepoxidationisachemicalreactiondescribedastheasymmetricepoxidationofalkeneswithoxone(potassiumperoxymonosulfate)andafructose-derivedcatalyst(1).Thisreactionisthoughttoproceedviaadioxiraneintermediate,generatedfromthecatalystketonebyoxone(potassiumperoxymonosulfate).Theadditionofthesulfategroupbytheoxonefacilitatestheformationofthedioxiranebyactingasagoodleavinggroupduringringclosure.Itisnotab...[
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該反應是1958年加拿大的化學家Brook發現報道的。α-矽基氧負離子通過生成一個五配位矽中間體重排得到α-矽氧基碳負離子的反應稱為[1,2]-Brook重排，或[1,2]-矽基遷移。後來發現此類矽遷移反應普遍存在，因此[1,n]-矽基由碳原子遷移到氧原子的反應統稱為Brook重排。矽原子上的取代基可以是脂肪基團或芳香基團，醇可以是仲醇或叔醇，酚也可以發生此反應。常用的堿有胺類[
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Weinreb酮合成法是有機金屬親核試劑（如：格氏試劑、有機鋰試劑）與Weinreb酰胺（N-甲氧基-N-甲基酰胺）反應製備酮的方法。Weinreb酰胺與金屬氫化物（如：氫化鋁鋰）反應也是製備醛的標準方法。反應機理與一般的羧酸衍生物（如酯、普通的酰胺、酰鹵）相比，該試劑的主要優點在於避免了與金屬有機試劑加成時的過量添加問題。對於一般的羧酸衍生物而言，兩個當量的親核基[
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HATU(1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium3-oxidehexafluorophosphate,HexafluorophosphateAzabenzotriazoleTetramethylUronium)isareagentusedinpeptidecouplingchemistrytogenerateanactiveesterfromacarboxylicacid.HATUisusedalongwithHünig'sbase(N,N-diisopropylethylamine,DIPEA),ortriethylaminetoformamidebonds.TypicallyDMFisusedassolvent,althoughotherpolaraproticsolvent...[
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用酒精消毒，是大家都知道的常識。可奇怪的是，在醫療上所用的消毒酒精是濃度為75％的酒精，純酒精反而不能殺菌。這是什麽原因呢？酒精的學名叫做乙醇（C2H5OH），它具有很強的滲透力，能夠鑽入細菌內部，使菌體蛋白質凝固（化學上叫做變性），造成細菌因失去活性而死亡。不同濃度的醫用酒精，它的作用是不同的。25%～50%的酒精，可用於物理退熱。40%～50%的酒精，可[
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