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  • 學位論文

過渡金屬應用於烯炔類分子進行分子內環化反應之研究

Transition-Metal Catalyzed Intramolecular Cyclization of Enynes

指導教授 : 劉瑞雄

摘要


本論文分成四個部分,主要是利用過渡金屬釕和金催化具有不飽和雙鍵和參鍵的有機小分子化合物進行環化反應。   第一部份是利用TpRuPPh3(CH3CN)2PF6為催化劑,在不加任何有機促進劑的情況下,催化3,5-雙烯-1-炔類分子作6-endo-dig環化反應,而產生具有多取代的苯環衍生物,在反應的過程中符合原子經濟效應,此外,在非環狀系統的取代基中,會有1,2-甲基位移及長碳鏈加成的現象產生,此反應提供在合成具有多取代基的苯環衍生物上一個簡單且具有位向選擇性的方法。   第二部分我們以相同的釕金屬錯合物TpRu(PPh3)(CH3CN)2PF6為催化劑,催化具有6,6-雙取代的3,5-雙烯-1-炔類化合物作環化反應,此反應會經由1,7-氫轉移的過程來完成反應,此外,我們也藉由改變1號和6號碳上的取代基而增加其反應效率,而1,7-氫轉移的現象類似“質子性”氫的轉移,為了使此反應在合成上變的更有應用性,我們發展了串聯式醛醇縮合脫水和環化反應,此反應是利用3-烯-1-炔-5-醛和環酮類分子在弱酸性的CpRu(PPh3)2Cl催化下,可以得到結構複雜的苯環衍生物,且在產率上有不錯的表現,藉由此1,7-氫轉移的現象我們可以導入鹵素及有機錫到苯環的甲基上,有助於未來在有機合成上的應用。   第三部分是利用AuPPh3SbF6錯合物催化具有arenyne-yne官能基的化合物,有效率地在溫和的條件下進行[3+2]-環化加成反應,在本反應中使用具有不同官能基的雙炔類分子都可以得到相當不錯產率的[3+2]-環化加成產物,同時也利用同位素標定實驗,驗證所推測的反應機構是經由[3+2]-環化加成的路徑,這個方法提供了在合成具有多環取代基的化合物上,簡易且符合原子經濟效應,有助於未來有機合成上的應用。   第四部分是利用利用金金屬錯合物在溫和的條件下,有效率的催化1,6-雙炔-4-烯-3-醇類和1,6-雙炔-4-烯-3-甲氧基類化合物作分子內環化反應形成萘酮類衍生物,反應過程主要是經由碳陽離子錯合物的形成而完成反應,藉由改變配位基上的羥基和甲氧基取代時,可分別的得到經由不同的途徑所生成萘酮類衍生物,本反應對於官能基容忍度的表現上極佳,未來希望可藉由此催化系統應用於合成具有不同官能基的的萘酮類化合物上。

並列摘要


Chapter I   In this chapter, we report a new ruthenium-catalyzed 6-endo-dig cyclization of 6,6-cycloalkylidenyl-3,5-dien-1-ynes, which produces highly substituted benzenes with considerable structural reorganization. In this process, we observe a regioselective 1,3-methylene migration via extrusion from a cycloalkylidenyl ring, in addition to a regiocontrolled 1,2-alkyl migration. This cyclization provides an easy and convenient synthesis of complex benzenes bearing various distinct substituents.   Chapter II describes the feasibility of thermal and catalytic cyclization of 6,6-disubstituted 3,5-dien-1-ynes via a 1,7-hydrogen shift. We first studied the thermal efficiency of model molecules via alternation of the C(1)-phenyl and C(6)-carbonyl substituents of substrates; we concluded that the observed 1,7-hydrogen shift is nearly a “protonic” hydrogen shift. This structure-activity relationship indicates that π-alkyne activators can catalyze suitably functionalized 3,5-dien-1-ynes efficiently although their thermal yields were generally low. We prepared various 6,6-disubstituted 3,5-dien-1-ynes bearing either a phenyl or carbonyl group, and found their thermal cyclizations to be greatly enhanced by RuCl3, PtCl2, TpRuPPh3(CH3CN)2PF6 catalysts to confirm our hypothesis: the C(7)-H acidity of 3,5-dien-1-ynes is crucial for thermal cyclization. To achieve the atom economy, we have developed a tandem aldol condensation-dehydration and aromatization catalysis between cycloalkanones and special 3-en-1-yn-5-als using the weakly acidic catalyst CpRu(PPh3)2Cl, which provided complex 1-indanones and α-tetralones with yields exceeding 65% in most cases.   In chapter III, we report a new efficient intramolecular [3+2]-cycloaddition of unactivated arenyne (or enyne)-yne function-nalities, catalyzed mainly by AuPPh3SbF6 complex under ambient conditions. The value of this cyclization is reflected by its applicability to a wide range of diyne substrates bearing various functional groups.   In chapter IV, we report a new efficient gold-catalyzed cyclization of 1,6-diyne-4-en-3-ol and 1,6-diyne-4-en-3-methoxy derivatives to give naphthyl ketone derivatives under ambient conditions. The cyclization is proposed to proceed via a vinylgold carbocation species, which subsequently triggers the cyclization via a 6-endo-dig attack of the allene group or intramolecular cycloadditon. The value of this cyclization is reflected by its applicability to a wide range of alcohol and methoxy substrates bearing various functional groups.

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