通過醛類與二硒醚之耦合反應合成硒酯化合物

A DTBP-promoted C-H selenation of aldehydes with diselenides under metal-free and solvent-free conditions is described. This system shows good functional group compatiblility, functional groups including bromo, trifluoromethyl, chloro, amine and heterocyclo-containing moieties including thiophene and furan are all tolerated by the reaction conditions employed. Both diaryl and dialkyl diselenides reacted smoothly with aldehydes to provide selenoesters in good to excellent yields.本論文探討的二叔丁基過氧化物在無金屬以及無溶劑下促進醛類上的碳-氫鍵硒化。此系統下有很好的官能基容忍性，官能基包括有溴基、三氟甲基、氯基、氨基，還有噻吩、呋喃等雜環官能基。二芳香基二硒醚和二烷基二硒醚都能與醛類反應提供產率不錯的硒酯化合物。摘要…………………………………………………………………….....i 英文摘要………………………………………………………………....ii 目錄……………………………………………………………………...iii 表目錄…………………………………………………………………....v 圖目錄…………………………………………………………………...vi 第一章　緒論…………………………………………………………....1 　　第一節　過渡金屬催化之耦合反應…….…………………...........1 　　第二節　碳-碳鍵之交互耦合應……………………………….......2 　　第三節 碳-氮鍵之交互耦合反應……………………………….....4 　　第四節 碳-氧鍵之交互耦合反應……………………………….....5 　　第五節 碳-硫鍵之交互耦合反應………………………………….8 　　第六節 羧酸衍生物之合成………………………………………27 　　第七節　碳-硒鍵的合成及其介紹………………………….........35 第二章 通過醛類與二硒醚之耦合反應合成硒酯化合物……………37 　　第一節　研究動機………………………………………………..37 　　第二節　結果與討論……………………………………………..41 　　第三節　結論……………………………………………………..51 第三章 儀器設備與藥品溶劑………………………………………....52 　　(一) 儀器設備…………………………………………………….52 　　(二) 藥品溶劑…………………………………………………….53 實驗步驟………………………………………………………………..54 光譜數據………………………………………………………………..59 參考文獻………………………………………………………………..86 NMR光譜………………………………………………………………9

Phytoplasma SAP11 alters 3-isobutyl-2-methoxypyrazine biosynthesis in Nicotiana benthamiana by suppressing NbOMT

Phytoplasma effector SAP11 modulates plant volatile organic compound emissions by suppressing the expression of NbOMT1, which encodes an O-methyltransferase required for the biosynthesis of 3-isobutyl-2-methoxypyrazine.Phytoplasmas are bacterial phytopathogens that release virulence effectors into sieve cells and act systemically to affect the physiological and morphological state of host plants to promote successful pathogenesis. We show here that transgenic Nicotiana benthamiana lines expressing the secreted effector SAP11 from Candidatus Phytoplasma mali exhibit an altered aroma phenotype. This phenomenon is correlated with defects in the development of glandular trichomes and the biosynthesis of 3-isobutyl-2-methoxypyrazine (IBMP). IBMP is a volatile organic compound (VOC) synthesized by an O-methyltransferase, via a methylation step, from a non-volatile precursor, 3-isobutyl-2-hydroxypyrazine (IBHP). Based on comparative and functional genomics analyses, NbOMT1, which encodes an O-methyltransferase, was found to be highly suppressed in SAP11-transgenic plants. We further silenced NbOMT1 through virus-induced gene silencing and demonstrated that this enzyme influenced the accumulation of IBMP in N. benthamiana. In vitro biochemical analyses also showed that NbOMT1 can catalyse IBHP O-methylation in the presence of S-adenosyl-L-methionine. Our study suggests that the phytoplasma effector SAP11 has the ability to modulate host VOC emissions. In addition, we also demonstrated that SAP11 destabilized TCP transcription factors and suppressed jasmonic acid responses in N. benthamiana. These findings provide valuable insights into understanding how phytoplasma effectors influence plant volatiles