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1、有機(jī)催化論文:手性伯胺催化不對(duì)稱Michael反應(yīng)研究【中文摘要】用有機(jī)催化的不對(duì)稱Michael反應(yīng)以形成新的C-C鍵,從而高效地從簡(jiǎn)單的前體分子構(gòu)建復(fù)雜的分子結(jié)構(gòu),近年來得到廣泛發(fā)展,也大大拓展了有機(jī)催化在不對(duì)稱催化領(lǐng)域的應(yīng)用。本論文首先較全面地綜述了手性伯胺催化不對(duì)稱反應(yīng)的研究現(xiàn)狀,特別是不對(duì)稱Michael反應(yīng)的研究進(jìn)展。在此基礎(chǔ)上,對(duì)手性伯胺分別催化2-羥基-1,4-萘醌和β-二酮酯與α,β-不飽和酮的不對(duì)稱Michael反應(yīng)進(jìn)行了較深入的研究。通過手性伯胺催化2-羥基-1,4-萘醌和α,β-不飽和酮的不對(duì)稱Michael反應(yīng)實(shí)現(xiàn)了Lapachol類似物的手性合
2、成。由天然金雞納堿作為手性源,合成的一系列金雞納堿手性伯胺催化劑,在以三氟乙酸為助催化劑的條件下,對(duì)各種α,β-不飽和酮都有較好的催化活性(高達(dá)93%收率)和對(duì)映選擇性(高達(dá)98%ee)。通過圓二色CD光譜與計(jì)算相結(jié)合的方法確定了產(chǎn)物的絕對(duì)構(gòu)型,并通過ESI-MS確證了反應(yīng)關(guān)鍵中間體的存在,證實(shí)了亞胺離子的活化機(jī)理。通過手性伯胺催化劑實(shí)現(xiàn)了β-二酮酯和α,β-不飽和酮的不對(duì)稱Michael反應(yīng)。金雞納堿型手性伯胺催化劑對(duì)各種α,β-不飽和酮和β-二酮酯底物都有較好的催化活性,取得了較高的收率(高達(dá)93%)和對(duì)映體選擇性(最高大于99.5%ee)。通過ESI-MS發(fā)現(xiàn)伯胺與
3、不飽和酮形成亞胺活化的關(guān)鍵中間體,證實(shí)了手性伯胺催化劑與反應(yīng)底物通過亞胺離子與氫鍵協(xié)同催化活化的反應(yīng)過渡態(tài)模型。【英文摘要】ThestrategyoforganocatalyticasymmetricMichaeladditionreactiontoformnewC-Cbondforcomplexmolecularstructuresfromsimpleprecursorshasbeenwidelydevelopedintherecentyearsandalsogreatlyexpandthefieldoforganocatalyticapplicationsinasym
4、metricsynthesis.Inthisdissertation,recentadvancesinthechiralprimaryaminescatalyzedasymmetricreactionsweresummarizedandreviewed,particularlytheasymmetricMichaelreactions.Onthisbasisofabove,theprimaryaminecatalyzedMichaelreactionsofα,β-unsaturatedketoneswith2-hydroxy-1,4-naphthoquinoneandβ-
5、ketoestersweremadein-depthstudyrespectively.AnenantioselectiveMichaelreactionofsubstitutedα,β-unsaturatedketoneswith2-hydroxy-1,4-naphthoquinonehasbeendevelopedbyusingachiralprimaryamineorganocatalystderivatedfromcinchonacombinedwithaco-catalystTFAfortheasymmetricsynthesisoflapacholanalog
6、ues.Thecorrespondingproductswereobtainedinmoderatetogoodyields(upto93%yield)withupto98%eeundermildconditions.Todeterminetheabsoluteconfigurationsofthefinaladducts,ausefultechniquebycomparingtheelectroniccirculardichroism(ECD)spectraofthechiralproductwithcalculatedtime-dependentdensityfunc
7、tionaltheory(TDDFT)resultswasadopted.BasedontheexperimentalresultsandESI-MSofseveralkeyintermediates,theactivationmechanismofiminiumionwasconfirmed.Inthefollowingstudy,anenantioselectiveMichealreactionofα,β-unsaturatedketoneswithβ-ketoesterpromotedbysimplechiralprim