第一部分：透過可見光光照射且不需要加入光敏劑的條件下，1,2-二氫-3-氧喹唑啉呸啶衍生物可以轉換為喹唑啉酮。藉由中間物與副產物的鑑定，我們提出合理的可見光光誘導反應機構。此外，我們設計3個兩性物質為主體的光敏劑，藉由斯特恩-沃爾默關係分析與反應機構的推導，確認他們在可見光光氧化還原催化中作為光敏劑的潛力，並同時具有氧化淬滅循環及還原淬滅循環雙重性質，其中一個光敏劑可以有選擇性的催化2,3-二氫亞氨基呸啶得到亞氨基吡啶。 第二部分：我們設計合成3種不同稠合位向的吡咯-香豆素稠合衍生物，並探討其潛在之電致變色性質。另外，我們運用烯胺與4-氯-3-硝基香豆素進行親核性取代反應作為關鍵步驟，用以天然物Ningalin B之全合成，其總反應為5步且總產率為42%。 Part I : Methyl-2-phenylquinazolin-4(1H)-ones were synthesized in good yield by exposing 1,4-dimethyl-2-phenyl-1,2-dihydroquinazoline 3-oxides or 1-methyl-2-phenyl-1,2-dihydroquinazoline 3-oxides to visible light in acetonitrile without the presence of any external photosensitizers. The key intermediate for this photochemical reaction was isolated and identified to be 1-methyl-2-phenyl-1,4-dihydroquinazolin-4-ol. The mechanism of this photosensitizer-free, visible-light-mediated reaction was proposed.Three organic zwitterions were designed and synthesized to evaluate their potentials to function as photosensitizers in visible light photoredox catalysis. Two of them were found to exhibit dual oxidative and reductive quenching properties via Stern-Volmer analysis. One designed photosensitizer can selectively catalyze the oxidation of 2,3-dihydro-1H-perimidines to the corresponding 1H-perimidines.Part II : Three types of pyrrolocoumarin-based derivatives were synthesized to explore their electrochromic properties. Moreover, an efficient construction of 1-phenylchromeno[3,4-b]pyrrol-4(3H)-one via coupling of 1-styrylpyrrolidine and 4-chloro-3-nitrocoumarin as a key step is applied to the total synthesis of the natural product ningalin B in five linear steps with an overall yield of 42%.
