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The most commonly used precatalysts for the Sonogashira reaction include [PdCl2ACHTUNGTRENUNG(PPh3)2],PdCl2/PPh3, and [PdACHTUNGTRENUNG(PPh3)4] with CuI as cocatalyst, which are effective for very reactive organic halides (e.g., vinyl and aryl iodides). We first utilized the [PdACHTUNGTRENUNG(PPh3)4]/CuI catalyst to synthesize PSNs, and obtained PSN-1 to PSN-3 from the crosscoupling of BrPh-D4R with 1–3, respectively. Progress of the reaction was evaluated by means of the residual amount of bromine. Energy-dispersive X-ray fluorescence spectroscopic data revealed that the Br/Si molar ratio of the obtained PSNs (after 48 h of the reaction; see details in the Experimental Section) was about 0.55, which corresponds to 45% conversion of phenyl bromides. As aryl bromides are less reactive electrophiles in Sonogashira coupling, a more active catalyst is needed. Palladium catalysts incorporating sterically demanding,electron-rich phosphines can furnish unusually high reactivity in a wide spectrum of coupling reactions. In particular, PtBu3 and bis(1-adamantyl)benzylphosphine ((1-Ad)2PBn) have proved to be exceptionally effective ligands for the Sonogashira reaction. Therefore,we tested Na2PdCl4/ACHTUNGTRENUNG[tBu3PH]BF4/CuI as precatalyst for our system.The phosphonium salt was used as a ligand precursor because it is insensitive toward oxidation and hence easily handled.[26e] The Br/Si molar ratios of PSN-1 to PSN-3 obtained with the Na2PdCl4/ACHTUNGTRENUNG[tBu3PH]BF4/CuI precatalyst were 0.13, 0.09, and 0.08, respectively, which suggests that less than one phenyl bromide moiety per D4R cage was left in the polymer networks. Thus, the present catalytic system was effective enough for constructing the PSNs.To investigate the effects of the length and connection points of the ethynyl compounds on physicochemical properties of the resulting PSNs, all reactions were carried out under the same conditions (concentration of the D4R compound, catalyst loading, reaction temperature and time, and molar ratio of ethynyl to aryl bromide groups). |
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大四寫論文: 金幣+50, ★★★很有幫助 2015-03-20 13:15:22
大四寫論文: 金幣+50, ★★★很有幫助 2015-03-20 13:15:22
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The most commonly used precatalysts for the Sonogashira reaction include [PdCl2ACHTUNGTRENUNG(PPh3)2],PdCl2/PPh3, and [PdACHTUNGTRENUNG(PPh3)4] with CuI as cocatalyst, which are effective for very reactive organic halides (e.g., vinyl and aryl iodides). 對于薗頭偶合反應(yīng)，最常見的預(yù)催化劑包括[PdCl2ACHTUNGTRENUNG(PPh3)2]，PdCl2/PPh3以及[PdACHTUNGTRENUNG(PPh3)4]和CuI(助催化劑)混合物, 它們對催化高活性有機(jī)鹵化物（例如乙烯基、芳基碘化物），也是有效的。 We first utilized the [PdACHTUNGTRENUNG(PPh3)4]/CuI catalyst to synthesize PSNs, and obtained PSN-1 to PSN-3 from the crosscoupling of BrPh-D4R with 1–3, respectively. 首先我們利用[PdACHTUNGTRENUNG(PPh3)4]/CuI催化劑來合成PSNs，同時對BrPh-D4R與BrPh-D4R 1–3分別進(jìn)行交叉耦合，從而得到PSN-1 PSN-2 PSN-3. Progress of the reaction was evaluated by means of the residual amount of bromine. Energy-dispersive X-ray fluorescence spectroscopic data revealed that the Br/Si molar ratio of the obtained PSNs (after 48 h of the reaction; see details in the Experimental Section) was about 0.55, which corresponds to 45% conversion of phenyl bromides. 運(yùn)用殘余的溴，對反應(yīng)過程進(jìn)行評價。能量色散x射線熒光光譜數(shù)據(jù)顯示，所獲得的PSNs的Br / Si摩爾比率（反應(yīng)48小時后，參見具體的實(shí)驗(yàn)部分）約為0.55，相當(dāng)于45%的溴苯轉(zhuǎn)換。 As aryl bromides are less reactive electrophiles in Sonogashira coupling, a more active catalyst is needed. Palladium catalysts incorporating sterically demanding,electron-rich phosphines can furnish unusually high reactivity in a wide spectrum of coupling reactions. 由于芳基溴代物，在薗頭偶合反應(yīng)中，是低活性親電體，所以需要一種活性更高的催化劑。一種結(jié)合鈀催化劑，有空間需求的，富電子的膦類化合物，能在耦合反應(yīng)的寬頻譜中，提供非比尋常的高活性。 In particular, PtBu3 and bis(1-adamantyl)benzylphosphine ((1-Ad)2PBn) have proved to be exceptionally effective ligands for the Sonogashira reaction. Therefore,we tested Na2PdCl4/ACHTUNGTRENUNG[tBu3PH]BF4/CuI as precatalyst for our system. 值得一提的是，PtBu3 和 二度（1-金剛烷基）芐基磷化氫 ((1-Ad)2PBn)，被證明是薗頭偶合反應(yīng)，格外有效的配體。因此我們測試了預(yù)催化劑Na2PdCl4/ACHTUNGTRENUNG[tBu3PH]BF4/CuI，已確定其是否符合我們的系統(tǒng)。 The phosphonium salt was used as a ligand precursor because it is insensitive toward oxidation and hence easily handled.[26e] The Br/Si molar ratios of PSN-1 to PSN-3 obtained with the Na2PdCl4/ACHTUNGTRENUNG[tBu3PH]BF4/CuI precatalyst were 0.13, 0.09, and 0.08, respectively, which suggests that less than one phenyl bromide moiety per D4R cage was left in the polymer networks. 鏻鹽被當(dāng)作一種配位前體，因?yàn)樗鼘ρ趸幻舾校子谔幚�。[26e] Na2PdCl4/ACHTUNGTRENUNG[tBu3PH]BF4/CuI作為預(yù)催化劑，得到的PSN-1 PSN-2 PSN-3的Br/Si摩爾比，分別是0.13, 0.09, 和 0.08，這表明，每D4R籠 有低于一個溴苯部分的含量，被留在了聚合物網(wǎng)絡(luò)中。 Thus, the present catalytic system was effective enough for constructing the PSNs.To investigate the effects of the length and connection points of the ethynyl compounds on physicochemical properties of the resulting PSNs, all reactions were carried out under the same conditions (concentration of the D4R compound, catalyst loading, reaction temperature and time, and molar ratio of ethynyl to aryl bromide groups). 因此，目前的催化體系有足夠的活性，催化PSNs的生成。為了調(diào)查，乙炔基化合物的接點(diǎn)和長度，對生成物PSNs的物化性能的影響，所有的反應(yīng)都在相同的條件下進(jìn)行，形同的條件有D4R化合物的濃度，催化劑量，反應(yīng)溫度和反應(yīng)時間，以及 乙炔基與芳基溴銨組的摩爾比。 |
2樓2015-03-20 12:26:00
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