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翻译过程中出现一些句子和专业名词有些拿捏不准，希望能有哪位大侠帮忙翻一下。个别翻译也可以。 1.The innocuous nature of boronic acids, which are generally nontoxic and thermally, air-, and moisture-stable, isa practical advantage of the Suzuki reaction, relative to many other cross-coupling processes. 2.a large number of protocols for accomplishing the transformation, the choice of which depends on the structure of the reactants.1 Clearly, the development of a general protocol that could reliably effect cross-coupling, independent of the structure of the reactants, would be worthwhile. 3.In this report,we describe significant progress toward substantiating that possibility. 4.Thus, 4-chloroacetophenone cross-couples efficiently with sterically hindered, with electron-rich, and with electron-poor arylboronic acids(entries 1-3, Table 1).27 5.elevated reaction temperatures have been employed in essentially all of the reactions of aryl triflates that have been reported to date.38 6.We decided to explore other trialkylphosphines as ligands, based on speculation that the larger steric demand of a triflate relative to a halide might require the use of a less bulky, but nevertheless electronrich, phosphine. 7 4-methoxyphenyl triflate 8.Variation in the electronic nature of the aryl triflate and of the arylboronic acid is well-tolerated (entries 1-6, Table 5), as is the presence of ortho substituents (entry 7, Table 5; 5% Pd(OAc)2). 9.Suzuki Cross-Coupling of Sterically Hindered Substrates. 10.sterically hindered biaryls 11.For substrates that bear more than one halide/triflate, the ability to effect selective monofunctionalization through Suzuki crosscoupling can be a powerful tool.44 12.We have established that with the Pd2(dba)3/P(t-Bu)3 catalyst system it is possible to carry out highly selective monofunctionalizations of difunctionalized arenes (Table 7). 13.In the case of 4-bromophenyltriflate, we observe very selective reaction of the bromide in the presence of the triflate (entry 3, Table 7). 14.We developed the Suzuki cross-coupling methods reported above (Tables 1-5) with the goal of providing general and reliable procedures that should work on the first try for a large majority of the substrates that one might encounter; we therefore did not attempt to optimize reaction conditions for each substrate pair. 15.To provide a sense for the turnover numbers that are achievable with Pd2(dba)3/P(t-Bu)3, 16.olefins that bear a substituent geminal to the chloro group react cleanly under these conditions. The cross-coupling of 1-chloro-2-methylbutene establishes that the reaction also tolerates a substituent cis to the chloride (entry 3). 17.Previous reports have been limited to activated substrates wherein the vinyl chloride is conjugated to an electron-withdrawing group. 18.Due to the potential lability of vinyl triflates, the availability of mild reaction conditions can be critical for efficient coupling of sensitive substrates. 19.Even extremely hindered substrates cross-couple under these conditions， although the reaction requires a higher catalyst loading and proceeds in somewhat lower yield if the boronic acid is also bulky (entries 8 and 9, Table 9). 20.the steric demand favors dissociation (relative to less bulky phosphines) to a monophosphine complex that, due to the donating ability of P(t-Bu)3, readily undergoes oxidative addition. 21.but that ratelimiting transmetalation of the resulting Pd(P(t-Bu)3)(Ar)(I) is less rapid than is transmetalation of Pd(P(t-Bu)3)(Ar)(Br). 22.In Suzuki crosscoupling reactions, it is generally believed that Lewis-base additives facilitate the process by binding to the organoboron reagent, forming a more reactive four-coordinate “ate” complex that transfers the organic group to palladium。 23.a period of time during which the cross-coupling of 4-bromo-N,N-dimethyaniline and o-tolylboronic acid proceeds to completion in the presence of 3.3 equiv of KF. 24.phosphine-free palladium, 25.rather than the catalytically active monophosphine complex 26 4-chlorophenyltriflate 27.On the basis of first-try dependability, we therefore recommend use of the general protocol, although for large-scale applications it may be worthwhile to explore lowphosphine conditions. 28.With these versatile catalyst systems, electronically and sterically diverse reactants can be efficiently cross-coupled, without the need for substrate-specific optimization of reaction conditions. 29.for Pd2(dba)3/P(t-Bu)3, very high selectivity for the following order of reactivity, I > Br > Cl,with chlorides being much more reactive than triflates; |
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zyy816
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515825903931(金币+5,VIP+0): 12-22 17:50
515825903931(金币+5,VIP+0): 12-22 17:50
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1.The innocuous nature of boronic acids, which are generally nontoxic and thermally, air-, and moisture-stable, isa practical advantage of the Suzuki reaction, relative to many other cross-coupling processes. 1.相对于很多其他的交叉欧联工艺而言，硼酸通常具有无毒，热、空气、潮湿稳定性等无害特性，在Suzuki反应中有着实质性的优势。 3.In this report,we describe significant progress toward substantiating that possibility. 在本报告中，我们描述了证实那种可能性的重要进展。 [ Last edited by zyy816 on 2009-12-22 at 09:11 ] |
2楼2009-12-22 09:07:22
残阳下的孤独
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3楼2009-12-22 09:57:29
残阳下的孤独
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4楼2009-12-22 10:03:16
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zap65535(金币+2,VIP+0):鼓励新人 12-22 10:57
515825903931(金币+5,VIP+0): 12-22 17:51
zap65535(金币+2,VIP+0):鼓励新人 12-22 10:57
515825903931(金币+5,VIP+0): 12-22 17:51
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1.The innocuous nature of boronic acids, which are generally nontoxic and thermally, air-, and moisture-stable, is a practical advantage of the Suzuki reaction, relative to many other cross-coupling processes. 硼酸基本无毒而且对热、空气及湿度等稳定，凭借着硼酸的这些无害特性，使得Suzuki反应相对于众多其它交叉偶联反应而言，更具实用优势。 2. In this report, we describe significant progress toward substantiating that possibility. 本报告描述了实现那种可能性的重大进展。 |
5楼2009-12-22 10:11:03
6楼2009-12-22 10:14:15
7楼2009-12-22 10:19:53
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515825903931(金币+3,VIP+0): 12-22 17:52
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27.On the basis of first-try dependability, we therefore recommend use of the general protocol, although for large-scale applications it may be worthwhile to explore low phosphine conditions. 尽管对于大规模应用来说，开发低磷化氢的条件也许会有价值，但基于对初试结果的信赖，我们因此推荐使用常规方案。 |
8楼2009-12-22 10:26:54
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515825903931(金币+3,VIP+0): 12-22 17:52
515825903931(金币+3,VIP+0): 12-22 17:52
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28. With these versatile catalyst systems, electronically and sterically diverse reactants can be efficiently cross-coupled, without the need for substrate-specific optimization of reaction conditions. 凭借这些“神通广大”的催化剂系统，那些电子云和空间位阻各不相同的反应物都能有效地实现交叉偶联，无需针对底物对反应条件优化。 |
9楼2009-12-22 10:34:38
10楼2009-12-22 10:44:44