非膦鈀配合物的合成及其催化直接芳基化反應與Suzuki反應的研究
發(fā)布時間：2018-11-17 16:01
【摘要】：通過C-C偶聯(lián)反應可以合成含有芳環(huán)-芳環(huán)、芳環(huán)-雜環(huán)或雜環(huán)-雜環(huán)結構的化合物,在天然產(chǎn)物、醫(yī)藥、農(nóng)藥、電子材料等方面有著非常廣泛的應用。而C-H鍵直接芳基化和Suzuki偶聯(lián)反應是C-C偶聯(lián)中非常高效的方法,不僅條件溫和、綠色環(huán)保和成本低廉,而且原料性質(zhì)穩(wěn)定、易于貯存。用于催化上述反應的配體大都為膦配體,膦配體在位阻效應和電子效應方面都很優(yōu)秀,表現(xiàn)出了很好的催化活性,然而,膦配體在空氣下很不穩(wěn)定、毒性較大,限制了其大規(guī)模應用。因此,開發(fā)出催化活性優(yōu)良、對空氣穩(wěn)定的非膦配體,已成為有機催化領域的熱點。1.設計并合成了3個大位阻二亞胺鈀配合物,對其結構進行了1H NMR、13C NMR表征,并對C1和C3兩個單晶結構進行了X-射線單晶衍射。通過考察位阻效應對配合物催化活性的影響,我們發(fā)現(xiàn),較大位阻有利于直接芳基化反應。原因在于,還原消除步為決速步的直接芳基化中,位阻最大的二亞胺鈀配合物C3可以加快還原消除速度,促進整個催化循環(huán)。2.設計并合成了7個大位阻氮雜環(huán)卡賓鈀配合物,對其結構進行了1H NMR、13C NMR表征,并對K1、K3、K4、K6四個單晶結構進行了X-射線單晶衍射,考察了位阻效應和電子效應對配合物催化活性的影響。通過在骨架上引進苊基和在N-芳環(huán)上引進二苯甲基,同時加快了氧化加成與還原消除速度,促進整個催化循環(huán)。大π-π共軛苊基骨架能增強π電子給電子能力,提高氧化加成速度;鄰位引進大位阻二苯甲基可以提高還原消除速度,對位引進二苯甲基可與氯代芳烴有π-π堆積作用,促進氧化加成步驟。我們發(fā)現(xiàn),在氧化加成為決速步的Suzuki反應中,氮雜環(huán)卡賓鈀配合物K5的活性最好,而位阻最大的K7活性卻很差。其原因在于N-芳環(huán)鄰位位阻過大,導致配合物失去了柔性,可協(xié)調(diào)性太差,抑制了氧化加成的進行,因此,位阻適中的K5為最佳催化劑。3.分別將其催化五元雜環(huán)及其衍生物C-H鍵直接芳基化反應、芳基/雜環(huán)氯代物與芳基/雜環(huán)硼酸的Suzuki反應。考察了配合物的位阻效應、電子效應、堿和溶劑等因素對偶聯(lián)產(chǎn)率和官能團容忍性的影響。3.1α-二亞胺鈀配合物催化C-H鍵直接芳基化反應的研究結果表明:C1-C3都能有效地在五元雜環(huán)α位進行C-H鍵直接芳基化反應。其中C3的活性最高,最佳反應條件:C3(0.5-0.1 mol%)、K2CO3(2.0 eq)、DMAc作為溶劑,在130 oC下反應12h,GC偶聯(lián)產(chǎn)率最高可達99%。3.2氮雜環(huán)卡賓鈀配合物催化Suzuki偶聯(lián)反應的研究在弱堿、空氣條件下,通過K5催化Suzuki偶聯(lián)反應合成了一系列芳環(huán)-芳環(huán)、芳環(huán)-雜環(huán)和雜環(huán)-雜環(huán)偶聯(lián)產(chǎn)物,其中K5的催化活性最高,催化劑用量可降低至0.025 mol%。最佳反應條件為:K5作催化劑、K2CO3為堿、無水乙醇作溶劑,在空氣下80oC反應4h,GC偶聯(lián)產(chǎn)率高達99%。
[Abstract]:Compounds containing aromatic ring, aromatic ring or heterocyclic structure can be synthesized by C-C coupling reaction. They have been widely used in natural products, medicine, pesticides, electronic materials and so on. The direct arylation of C-H bond with Suzuki coupling reaction is a very efficient method in C-C coupling. It is not only mild, green and low cost, but also stable in properties of raw materials and easy to store. Most of the ligands used to catalyze the above reactions are phosphine ligands. The phosphine ligands are excellent in the field of steric and electronic effects and exhibit good catalytic activity. However, the phosphine ligands are unstable and toxic in the air. It limits its application on a large scale. Therefore, the development of non-phosphine ligands with excellent catalytic activity and air stability has become a hot spot in the field of organic catalysis. Three large hindrance diimide palladium complexes were designed and synthesized. Their structures were characterized by 1H NMR,13C NMR, and the single crystal structure C1 and C3 were characterized by X-ray single crystal diffraction. By investigating the effect of steric resistance on the catalytic activity of the complexes, we found that the larger steric resistance is beneficial to the direct arylation reaction. The reason is that in the direct arylation of the reduction elimination step, the complex C _ 3, which has the largest steric resistance, can accelerate the reduction removal rate and promote the whole catalytic cycle. Seven carbene palladium complexes with large steric hindrance have been designed and synthesized. Their structures have been characterized by 1H NMR,13C NMR. The effects of steric resistance and electron effect on the catalytic activity of the complexes were investigated. By introducing acenaphthene on the skeleton and diphenyl methyl on the N-aromatic ring, the oxidation addition and reduction elimination rate were accelerated, and the whole catalytic cycle was promoted. The skeleton of large 蟺-蟺 conjugated acenaphthene can enhance the electron feeding capacity of 蟺 and increase the oxidation addition rate. The reduction removal rate can be improved by introducing biphenylmethyl with large steric hindrance at o-site, and 蟺-蟺 stacking with chlorinated aromatics can be obtained by introducing diphenylmethyl to p-position, thus promoting the oxidation addition step. It is found that in the Suzuki reaction, the activity of carbene palladium complex K5 is the best, while the activity of K7 with the largest steric resistance is very poor. The reason is that the N- aryl ring orthosteric resistance is too large, which leads to the loss of flexibility, poor coordination and inhibition of oxidation addition. Therefore, K _ 5 with moderate steric resistance is the best catalyst. It catalyzes the direct arylation of C-H bond and the Suzuki reaction of aryl / heterocyclic chlorides with aryl / heterocyclic boric acid. The steric and electron effects of the complexes were investigated. The effect of alkali and solvent on the coupling yield and the tolerance of functional groups. The results of direct arylation of C-H bond catalyzed by 3.1 偽 -diimide palladium complex show that C1-C3 is effective at the 偽 site of quaternary heterocyclic compounds. Direct arylation of C-H bond was carried out. The best reaction conditions were C3 (0.5-0.1 mol%), K2CO3 (2.0 eq), DMAc as solvent) for 12 h at 130 oC. Studies on the Suzuki Coupling reaction catalyzed by the Palladium complexes of nitrogen heterocyclic Carbenes with a maximum yield of 990.3.2 A series of aromatic rings were synthesized by K _ 5 catalyzed Suzuki coupling reaction under the condition of weak base and air. The coupling products of aromatic ring heterocyclic and heterocyclic are the most active, and the amount of catalyst can be reduced to 0.025 mol%.. The optimum reaction conditions were as follows: K5 as catalyst, K2CO3 as base, anhydrous ethanol as solvent, and 80oC reaction in air for 4 h, the coupling yield of GC was as high as 99wt%.
【學位授予單位】：廣東藥科大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：O641.4;O621.251
本文編號：2338380
[Abstract]:Compounds containing aromatic ring, aromatic ring or heterocyclic structure can be synthesized by C-C coupling reaction. They have been widely used in natural products, medicine, pesticides, electronic materials and so on. The direct arylation of C-H bond with Suzuki coupling reaction is a very efficient method in C-C coupling. It is not only mild, green and low cost, but also stable in properties of raw materials and easy to store. Most of the ligands used to catalyze the above reactions are phosphine ligands. The phosphine ligands are excellent in the field of steric and electronic effects and exhibit good catalytic activity. However, the phosphine ligands are unstable and toxic in the air. It limits its application on a large scale. Therefore, the development of non-phosphine ligands with excellent catalytic activity and air stability has become a hot spot in the field of organic catalysis. Three large hindrance diimide palladium complexes were designed and synthesized. Their structures were characterized by 1H NMR,13C NMR, and the single crystal structure C1 and C3 were characterized by X-ray single crystal diffraction. By investigating the effect of steric resistance on the catalytic activity of the complexes, we found that the larger steric resistance is beneficial to the direct arylation reaction. The reason is that in the direct arylation of the reduction elimination step, the complex C _ 3, which has the largest steric resistance, can accelerate the reduction removal rate and promote the whole catalytic cycle. Seven carbene palladium complexes with large steric hindrance have been designed and synthesized. Their structures have been characterized by 1H NMR,13C NMR. The effects of steric resistance and electron effect on the catalytic activity of the complexes were investigated. By introducing acenaphthene on the skeleton and diphenyl methyl on the N-aromatic ring, the oxidation addition and reduction elimination rate were accelerated, and the whole catalytic cycle was promoted. The skeleton of large 蟺-蟺 conjugated acenaphthene can enhance the electron feeding capacity of 蟺 and increase the oxidation addition rate. The reduction removal rate can be improved by introducing biphenylmethyl with large steric hindrance at o-site, and 蟺-蟺 stacking with chlorinated aromatics can be obtained by introducing diphenylmethyl to p-position, thus promoting the oxidation addition step. It is found that in the Suzuki reaction, the activity of carbene palladium complex K5 is the best, while the activity of K7 with the largest steric resistance is very poor. The reason is that the N- aryl ring orthosteric resistance is too large, which leads to the loss of flexibility, poor coordination and inhibition of oxidation addition. Therefore, K _ 5 with moderate steric resistance is the best catalyst. It catalyzes the direct arylation of C-H bond and the Suzuki reaction of aryl / heterocyclic chlorides with aryl / heterocyclic boric acid. The steric and electron effects of the complexes were investigated. The effect of alkali and solvent on the coupling yield and the tolerance of functional groups. The results of direct arylation of C-H bond catalyzed by 3.1 偽 -diimide palladium complex show that C1-C3 is effective at the 偽 site of quaternary heterocyclic compounds. Direct arylation of C-H bond was carried out. The best reaction conditions were C3 (0.5-0.1 mol%), K2CO3 (2.0 eq), DMAc as solvent) for 12 h at 130 oC. Studies on the Suzuki Coupling reaction catalyzed by the Palladium complexes of nitrogen heterocyclic Carbenes with a maximum yield of 990.3.2 A series of aromatic rings were synthesized by K _ 5 catalyzed Suzuki coupling reaction under the condition of weak base and air. The coupling products of aromatic ring heterocyclic and heterocyclic are the most active, and the amount of catalyst can be reduced to 0.025 mol%.. The optimum reaction conditions were as follows: K5 as catalyst, K2CO3 as base, anhydrous ethanol as solvent, and 80oC reaction in air for 4 h, the coupling yield of GC was as high as 99wt%.
【學位授予單位】：廣東藥科大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：O641.4;O621.251
【參考文獻】
相關碩士學位論文 前1條
1 雷小莉;鈀催化的選擇性偶聯(lián)反應合成2-吡喃酮類化合物及銅催化的Chan-Lam偶聯(lián)反應研究[D];江西師范大學;2011年
，本文編號：2338380
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