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Palladium-Catalyzed Carbon-Carbon Coupling Reactions

2.1. Matsuda-Heck Reaction

2.1.1. Olefinic Coupling Partner

Kikukawa and Matsuda were the pioneers in studying the

reactivity of diazonium salts with transition metals. The

new method emerged as a complementary strategy to the

Meerwein reaction6 for the arylation of unactivated olefins

and also as an improvement on the method proposed in the

early studies with aryl halides that Mizoroki and Heck

separately conducted.20

Kikukawa和Matsuda是研究重氮盐与过渡金属盐反应的先驱者。

The olefins that were arylated were

styrene, cyclopentene, allylic alcohols, and ethyl acrylate.

The in situ reduction of LiPd(II)Cl3 by sodium formate or

Pd2(dba)3 as a source of Pd(0) in aqueous acetonitrile was

used as a catalytic system. The reaction occurred at room

temperature with sodium acetate as the base until production

of nitrogen gas ceased. The same authors extended the

methodology to the arylation of ethylene based on a

comparative study of a variety of monosubstituted arenediazonium

salts21,22 (Scheme 5).

Some exceptions were o and

p-nitrobenzenediazonium salts, which only gave nitrobenzene

as the main reaction product. It seems that the

reaction was also sensitive to the steric effects since mesitylenediazonium salt did not produce the corresponding

styrene. A specific application by the same authors was

vinylation of a benzocrown ether23

The detailed

study of acrylonitrile was taken up again in 2001 when Cai

et al.24 published a paper that investigated both the arylation

of acrylonitrile and acrylamide with various arenediazonium tetrafluoroborates using Pd(OAc)2 in EtOH at 80 ?C. The

corresponding (E)-cinnamonitrile and (E)-cinnamamide derivatives

were obtained in yields of between 78% and 89%.

In 2001, another paper published by Cai et al.25 reported yields of up to 63% for the arylation of alcohols 11 and 12 using Pd(OAc)2 as

the catalyst in EtOH at 60 ?C. More recently, Muzart,

Roglans et al.26 achieved the arylation of several allylic

alcohols with arenediazonium tetrafluoroborates with Pd2-

(dba)3 in MeOH, obtaining the corresponding protected

aldehydes 16 from primary alcohols 11 and 12 and ketones

19 from secondary alcohols 17 and 18 (Scheme 7).

One of the main limitations of olefin arylations by

diazonium salts is the instability of some of these salts at

room temperature. Studying the reaction of arylamines with styrene in the presence of palladium salts, Fujiwara et al.27 found that addition of an equimolar amount of tert-butyl

nitrite to the reaction mixture considerably improved the yields of the corresponding stilbenes. Inspired by Matsuda’s success in obtaining aryl-substituted olefins by a Pd-catalyzed reaction of the olefin and arenediazonium salts,19 Fujiwara described for the first time a direct domino diazotizationstyrene arylation by amines in the presence of palladium salts (Scheme 8). However, in the method used by Fujiwara, stoichiometric amounts of Pd(OAc)2 were required in order

to obtain good yields (conditions i in Scheme 8). At the same time, Matsuda et al.28 described the arylation of several

olefins by arylamines (the examples with styrene are given

in Scheme 8) using alkyl nitrite and catalytic amounts of

Pd2(dba)3. In this case it was necessary to add a mixture of monochloroacetic acid and acetic acid to improve the results (conditions ii in Scheme 8).

The “one-pot” diazotization-arylation reaction

was also subsequently employed by other authors. Beller et

al.29 described the direct synthesi s of substituted styrenes starting from several anilines and ethylene. The diazotization- arylation process took place in the presence of

t BuONO, acetic acid, and a catalytic amount (5 mol %) of

Pd(OAc)2 at room temperature and with ethylene under atmospheric pressure (Scheme 9).

Sengupta33 and Goeldner34 proposed an alternative to overcome the problem of the instability of arenediazonium salts based on the study of the effect of their counteranions

on the Matsuda-Heck reactions. Sengupta et al.33 generated several arenediazonium salts in situ with different counteranions (OAc, ClO4, F, CH3SO3, BF4, CF3CO2) by acidolysis

of 1-aryltriazenes with the corresponding acid and studied

their utility in the Matsuda-Heck reaction with ethyl acrylate. With the exception of acetic acid, all acids produced clean arylation processes in high yields (73-97%). For all cases studied, the more economical diazonium perchlorates

and fluorides gave better results than the corresponding isolated arenediazonium tetrafluoroborates. Goeldner et al.34 described an efficient, mild procedure for the synthesis of arenediazonium trifluoroacetates under anhydrous conditions. The method permitted production of large quantities of an extensive series of aniline derivatives. Their application in

the arylation of ethyl acrylate was studied in depth, and an interesting alternative to arenediazonium tetrafluoroborates was found.

A very recent contribution in this area is due to Barbero,

Fochi et al.35 and Dughera,36 which use arenediazonium

o-benzenedisulfonimides (Figure 1) as an interesting alternative to the more usual arenediazonium tetrafluoroborates.

These compounds are easy to prepare and isolate and are highly stable.37 Furthermore, benzenedisulfonimide is easily recovered for reuse at the end of the reaction. The authors

use this kind of arenediazonium salt in Matsuda-Heck35 and

Stille36 (see section 2.4.1.) coupling reactions.

It should be noted that in most cited cases reactions with

chloro-, bromo-, or iodo-substituted arenediazonium salts displayed a high degree of chemoselectivity, indicating the

superior reactivity of the diazonium nucleofuge over chloride, bromide, and even iodide. This fact illustrates one of the advantages of working with arenediazonium salts as arylating reagents in Matsuda-Heck reactions and shows that the

aryl-nitrogen bond is more reactive to zerovalent palladium

than aryl-halogen bonds. Sengupta38 and Xu39 have taken advantage of the above-mentioned differential coupling of

the nucleofuges.

Sengupta38 described a stepwise assembly

carried out on a 4-iodo-2-methylbenzenediazonium salt to

prepare unsymmetrical divinylbenzene derivatives (Scheme

11). As shown in Scheme 11, the different regioisomers were obtained by switching the order in which the olefins were

added.

Xu et al.39 also described the synthesis of unsymmetrical divinylbenzenes taking advantage of the superior reactivity

of arenediazonium salts as compared to aroyl chlorides.40

Several carboxybenzenediazonium salts were used to arylate methyl acrylate using Li2PdCl4-CuCl as a catalytic system

in a methanolic solution at room temperature in 10-30 min.

The corresponding alkenylated benzoic acids were transformed into their benzoyl chlorides, and this functionality

was used to run a second Pd-catalyzed arylation process.

Since it is known that arenediazonium salts in the presence

of Cu(I) can give a Meerwein reaction, the authors ran the reaction in the absence of Li2PdCl4 to confirm that this

reaction did not occur here. However, the authors do not

explain why CuCl is required (Scheme 12).

Two- and 4-fold Matsuda-Heck reactions of bisdiazonium

salts 20 and 21 and tetrakis-diazonium salt 22 were described

by Sengupta et al.41,42 as a further demonstration of the

greater reactivity of arenediazonium salts. Matsuda-Heck

adducts 23 and 24 were obtained after 1 h with 60-83%

yields when Pd(OAc)2 was used as a catalyst in EtOH at 80?C. Another specific demonstration of the superior reactivity

of arenediazonium salts over aryl halides as electrophiles in Matsuda-Heck reactions was given by Gene?t et al.43 on

studying the arylation of perfluoroalkenes.

2.2. Suzuki-Miyaura Reaction

It was not until 20 years after the first utilization of the arenediazonium salts in a palladium-catalyzed reactions that

these electrophiles were applied in Suzuki-Miyaura crosscouplings. This late discovery was made independently, but simultaneously, in the laboratories of Gene?t et al.83 and Sengupta at al.84 Moderate to good yields of biaryls were

obtained by coupling of arenediazonium tetrafluoroborates

and arylboronic acids in the presence of catalytic amounts

of Pd(OAc)2 and in the absence of both an added base and

ligands.

After the ini tial discovery the Gene?t group performed an

intensive study to improve the reaction by modifying the

boronic counterpart.85 The search for a more nucleophilic organoborane moiety led them to test potassium aryltrifluoroborates, whose easy preparation had been previously

reported by Vedejs et al.86 in the Suzuki-Miyaura coupling.

These very stable, water-resistant, and easily isolated nucleophiles were shown to be more efficient and reactive than

the corresponding organoboronic acids, leading to higher

product yields in shorter time periods

Gene?t et al.83b showed that alkenyl boronic acids could

also be effectively coupled to arenediazonium tetrafluoroborates using Pd(OAc)2 in 1,4-dioxane at room temperature.

Stilbene and styrene derivatives were obtained in good to

moderate yields (Scheme 31).

An elegant step forward was proposed by Gene?t et

al.85b,89 in describing an efficient synthesis for potassium vinyltrifluoroborate and studying its reactivity toward arenediazonium salts under palladium catalysis. Good yields

of differently substituted styrenes were obtained

As a logical follow-up on the diversification of substrates,

Gene?t et al.85b tried to extend the diazonium-trifluoroborate coupling to formation of sp2-sp carbon-carbon bonds.

2.3. Carbonylative Coupling

Kikukawa, Matsuda et al.97 pioneered the use of diazonium

salts in carbonylation reactions. They first reported the Pdcatalyzed reaction of arenediazonium tetrafluoroborates with

CO in the presence of sodium acetate, or other sodium carboxylates, in acetonitrile.

Kikukawa, Matsuda et

al.99 were again the pioneers in the Pd-catalyzed carbonylation

of arenediazonium salts in the presence of tin

compounds, and their first communication appeared in

1982,99a the same year that arylboronic acids were described

for the first time100

2.4.1. Stille Cross-Coupling

Conventional Stille couplings17 with diazonium salts have

attracted much less attention than both Suzuki-Miyaura

cross-couplings (section 2.2) and carbonylative couplings

involving organostannanes (section 2.3).

Kikukawa, Matsuda et al.79 reported methylations with

Me4Sn to give toluenes 103, arylations, as well as a vinylation

with CH2dCH-SnBu3 that produced styrene (Scheme 47). Methylation of diazonium salts, reported for the first time

in this study, was carried out using arenediazonium tetrafluoroborates

or hexafluorophosphates with different substituents,

giving moderate to good yields of substituted toluenes 103

in 2 h (Scheme 47).

2.4.2. Carbon Heteroatom Coupling

By analogy with carbonylations, Keim et al.104 prepared

sulfinic acids 104 by reaction of diazonium tetrafluoroborates

in an atmosphere of SO2 and hydrogen in the presence of

10 mol % Pd/C (Scheme 48). As a reducing agent, the

authors demonstrated that hydrogen was superior to silanes,

which had been used by Kikukawa et al.98 in reductive carbonylation processes.

Borylation of aromatics was achieved by Strongin et al.105

by palladium-catalyzed carbon-boron bond formation from arenediazonium tetrafluoroborates. Thus, arenediazonium

salts reacted with both halves of bis(pinacolato)diborane 105

in the presence of PdCl2(dppf) in refluxing methanol to afford boronic esters 106 (Scheme 49).

Two processes which do not fit any of our previous

headings involving arenediazonium salts in palladium crosscoupling reactions are shown in Scheme 50. A ternary

coupling between norbornadiene, arenediazonium tetrafluoroborates, and tin or boron compounds as formal donors of

Ph- or Ph-CtC-produced norbornenes 107 in moderate

to good yields.107

The second very different case is that of the reaction of benzenediazonium tetrafluoroborate with silyl enol ethers in

the presence of Pd(PPh3)4, NaBPh4 using pyridine as a

solvent to afford a 74% yield of R-phenyl ketone. However,

the reaction was more efficient in the absence of the

palladium catalyst, demonstrating that arylation proceeded

via a radical mechanism promoted by pyridine.108

Concluding Remarks

arenediazonium salts

are attractive partners in palladium-catalyzed cross-coupling reactions. In particular, Heck reactions involving arenediazonium salts have been extensively developed and widely

used in the synthesis of natural products and other complex organic compounds. There are fewer publications involving

use of these electrophiles in Suzuki-Miyaura, carbonylative, Stille, and carbon-heteroatom cross-couplings. A series of advantages of working with arenediazonium salts as electrophiles has been observed. Arenediazonium salts derive

from inexpensive aromatic anilines, and the corresponding tetrafluoroborates have the additional advantage of being

easily prepared in large quantities.

The

superior reactivity of the diazonium nucleofuge over halides

has also permitted the chemoselectivity of the crosscouplings, which has resulted in interesting applications being

developed. Moreover, the cross-couplings do not seem to be sensitive to the electronic nature of the substituents in the arenediazonium salts, which is an important drawback when aryl halides are used.

Synthesis of Oxindoles by Palladium-catalyzed C–H Bond Amidation

Synthesis of Oxindoles by Palladium-catalyzed C–H Bond Amidation Tomoya Miura,Yoshiteru Ito,and Masahiro Murakami ? Department of Synthetic Chemistry and Biological Chemistry,Kyoto University,Katsura,Kyoto 615-8510 (Received January 15,2009;CL-090055;E-mail:murakami@sbchem.kyoto-u.ac.jp) Treatment of N -tosylphenylacetamide derivatives with cop-per(II)acetate in the presence of a catalytic amount of palladi-um(II)acetate a?ords 3,3-disubstituted oxindoles.The reaction proceeds through the intramolecular metallation of an aromatic C–H bond and the following C–N bond formation by reductive elimination. The development of e?cient methods for the synthesis of nitrogen-containing heterocycles using transition-metal catalysts is of immense interest owing to the ubiquity of heterocyclic cores in natural products and pharmaceuticals.1Cyclization through the direct conversion of C–H bonds into C–N bonds would be attractive for the construction of these ring systems in view of atom economy and synthetic simplicity.2In 2005,Buchwald and co-workers reported a palladium-catalyzed syn-thesis of carbazoles from acetylated 2-phenylaniline via C–H functionalization forming a C–N bond.3Since then,the method has been applied to the synthesis of other classes of heterocycles using palladium-and/or copper-catalysts.4Herein,we describe a synthesis of oxindoles from N -tosylphenylacetamide derivatives facilitated by a combination of Pd(OAc)2and Cu(OAc)2.5 When N -tosyl-2-methyl-2-phenylpropanamide (1a )was treated with Pd(OAc)2(10mol %)in p -xylene at 140 C for 14h under an O 2atmosphere,the oxindole 2a was obtained in 15%yield (Table 1,Entry 1).6The e?ect of reoxidants as addi-tives was examined (Entries 2–5)to reveal that the reaction in the presence of Cu(OAc)2(1equiv)gave 2a in 82%yield.Re-ducing the amount of Cu(OAc)2to 0.3equiv and lowering the reaction temperature to 100 C decreased the yield of 2a (Entries 6and 7).The reaction under an O 2atmosphere proceeded faster than that under an Ar atmosphere (Entry 8).Although 4-nitro-benzenesulfonyl was also suitable as the protecting group of the amide (Entry 9),no reaction took place with 4-methoxyben-zyl-protected amide 1c (Entry 10). A proposed reaction pathway for the production of 2a from 1a is depicted in Scheme 1.Initially,the amide moiety of 1a binds to Pd(OAc)2forming the palladium amide A with concom-itant loss of a molecule of acetic acid.Then,cyclopalladation of A occurs to produce the six-membered-ring palladacycle B to-gether with another molecule of acetic acid.7Finally,reductive elimination a?ords 2a and a palladium(0)species,which is re-oxidized to Pd(OAc)2in the presence of Cu(OAc)2under an O 2atmosphere. Under optimized reaction conditions,a variety of N -tosyl-phenylacetamide derivatives reacted to a?ord the corresponding oxindoles in yields ranging from 30%to 97%(Table 2).8How-ever,nonsubstituted substrates on the methylene carbon such as N -tosylphenylacetamide failed to participate in the cyclization,presumably due to the gem -dialkyl e?ect.9The reaction of 1g and 1h bearing a substituent at the para position gave the desired oxindoles in good yields (Entries 4and 5).Whereas an electron-withdrawing chloro group was suitable as the meta substituent (Entry 6),an electron-donating methoxy group retarded the process (Entry 7).Notably,the C–H bond activation occurred exclusively at the less hindered 6-position of 1i and 1j .A similar electronic and steric e?ect was observed in the carbazole synthe-sis reported by Buchwald et al.3 The removal of the N -tosyl group in the products was readily achieved on treatment with magnesium in methanol under ultra-sonic radiation (eq 1).10 2a 3a 98%e1T In summary,we have demonstrated that the palladium-cata-lyzed C–H bond amidation of N -tosylphenylacetamide deriva- Table 1.Optimization of reaction conditions a 1 2 Me Me O Entry 1R 1Reoxidant (equiv)Gas T / C Yield/%b 11a Ts none O 21401521a Ts PhI(OAc)2(1)O 2140<531a Ts Benzoquinone (1)O 2140<541a Ts Ag 2CO 3(1)O 21408151a Ts Cu(OAc)2(1)O 21408261a Ts Cu(OAc)2(0.3)O 21406371a Ts Cu(OAc)2(1)O 21003581a Ts Cu(OAc)2(1)Ar 1404791b Ns Cu(OAc)2(1)O 21408410 1c PMB Cu(OAc)2(1) O 2 140 a Reactions conducted on a 0.2mmol scale.b Isolated yield.Ns =4-ni-trobenzenesulfonyl. O 2 1a Scheme 1.A plausible reaction pathway. Copyright ó2009The Chemical Society of Japan

商标国际分类-中英文对照

商标国际分类表中/英文对照 第一类用于工业、科学、摄影、农业、园艺、森林的化学品,未加工人造合成树脂,未加工塑料物质,肥料,灭火用合成物,淬火和金属焊接用制剂,保存食品用化学品,鞣料,工业粘合剂 [注释] 本类主要包括用于工业、科学和农业的化学制品,包括制造属于其他类别的产品用的化学制品. 尤其包括:堆肥;非食品防腐盐. 尤其不包括:未加工的天然树脂(第二类); 医学科学用化学制品(第五类); 杀真菌剂、除莠剂和消灭有害动物的制品(第五类); 文具用或家用粘合剂(第十六类); 食品用防腐盐(第三十类); 褥草(腐殖土的覆盖物)(第三十一类). 0101 工业气体,单质(共84 条商品/服务名称) 序号商品/服务名称 010086 砹Astatine 010061 氨Ammonia * 010101 钡Barium 010125 铋Bismuth 010092 氮Nitrogen 010516 锝Technetium 010250 镝Dysprosium 010517 碲Tellurium 010534 铥Thulium 010457 氡Radon 010276 铒Erbium 010302 氟Fluorine 010318 钆Gadolinium C010004 钙calcium 010333 干冰(二氧化碳)Dry ice [carbon dioxide] 010333 干冰(固体二氧化碳)Ice (Dry –) [carbon dioxide] C010005 工业硅industry silicon 010368 工业用碘Iodine for industrial purposes 010328 工业用固态气体Gases (Solidified –) for industrial purposes 010328 工业用固态气体Solidified gases for industrial purposes 010305 工业用石墨Graphite for industrial purposes 010387 汞Mercury 010483 硅Silicon C010007 海绵钯sponge palladium 010344 氦Helium 010326 焊接用保护气Welding (Protective gases for –) 010326 焊接用保护气Gases (Protective –) for welding 010326 焊接用保护气体Protective gases for welding 010365 化学用碘Iodine for chemical purposes

Bis(dibenzylideneacetone)palladium,双(二亚苄基丙酮)钯 MSDS

Material Safety Data Sheet Company Identification: RUIYUAN GROUP LIMITED YURUI(SHANGHAI)CHEMICAL CO.,LTD Address:No.2277Zuchongzhi Road,Pudong,Shanghai,China Zipcode:201203 Tel:+862150456736 Fax:+862160853441 Email:info@https://www.doczj.com/doc/639360464.html, 【Product Name】Bis(dibenzylideneacetone)palladium 【Synonyms】PD(DBA)2;PALLADIUM(0)BIS(DIBENZYLIDENEACETONE); Bis(dibenzylideneacetone)palladium(0)Pd(dba)2Pd2(dba)3dba 【CAS】32005-36-0 【Formula】C34H28O2Pd 【Molecular Weight】575.01 【EINECS】None known 【Appearance】Red-brown solid/powder 【Solubility in water】Insoluble 【Melting Point】150°C(302°F) 【Density】Not available.

【Vapor Density】Not available. 【Ingestion】 Never give anything by mouth to an unconscious person.Rinse mouth with water. 【Inhalation】 If breathed in,move person into fresh air.If not breathing,give artificial respiration. 【Skin】 Immediately flush skin with plenty of water for at least15minutes while removing contaminated clothing and shoes.Get medical aid if irritation develops or persists. 【Eyes】 Immediately flush eyes with plenty of water for at least15minutes,occasionally lifting the upper and lower eyelids.If irritation develo ps,get medical aid. 【Storage】 Keep container tightly closed in a dry and well-ventilated place. Air and moisture sensitive.Store under inert gas. 【Handling】 Provide appropriate exhaust ventilation at places where dust is formed.Normal measures for preventive fire protection. 【Inhalation】 May cause respiratory tract irritation.May be harmful if inhaled. 【Skin】

英语翻译

Elctrochemical Preparation and High Performance of Platinum and Palladium Nanocatalysts with High-Index Facets Summary:By developing the electrochemically shape-controlled synthesis method in this thesis, the surface structure and the growth of metal nanocatalysts have been well controlled. As results, we have prepared successfully not only platinum and palladium tetrahexahedral nanocatalysts, but also other nanocrystals of various shape enclosed by different high-index facets. The current study has enriched the contents of controlling the surface structure and the growth of metal nanocrystals, and has deepened the understanding of the growth habits of metal nanocrystals. We have been invited by J. Phys. Chem. to write a Feature Article based on these above results (N. Tian, et al, J. Phys. Chem., 2008, 112: 19801-19817). The as-prepared platinum-group nanocatalysts enclosed by high-index facets exhibit high activity and stability, which have opened an exciting avenue to improve the performance of metal nanocatalysts by means of controlling surface atomic arrangement, and made a breakthrough in the design and preparation of practical catalysts directed by the knowledge gained in fundamental studies of model catalysis using metal single crystal planes as model electrocatalysts. Key words:platinum-group metals, nanocrystals, high-index facets, electrocatalysis Platinum-group metal nanomaterials are widely used as catalysts applied in fuel cells, petroleum catalytic reform, automotive catalytic converters and other important fields. Among the platinum-group metals used as catalysts in the world, the platinum is consumed as high as 100 tons per year, which values more than 7 billion US dollars. The price of platinum-group metal is extremely high due to their rare reserve on the earth. So, the key scientific and technological issue of platinum catalysts is to further improve their activity, stability and utilization efficiency. Generally, catalytic properties of nanocrystals can be finely tuned either by their composition, which mediates electronic structure, or by their shape, which determines their surface atomic arrangement and coordination. Fundamental studies of model catalysts using single-crystal planes have demonstrated that high-index planes of platinum-group metals exhibit generally much higher catalytic activity and stability than those of the low-index planes, such as {111}, {100}, and even {110}, because

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珠宝英语 宝石(Stone) 钻石Diamond红宝石Ruby蓝宝石Sapphire 祖母绿Emerald 绿柱石Beryl 锆石Zircon橄榄石Peridot 石榴石Garnet 石英Quartz 水晶Rock crystal 翡翠Jadeite 绿松石Turquoise 孔雀石Malachite大理石Marble 寿山石Lardetite 珍珠Pearl 珊瑚Coral 琥珀Amber 象牙Ivory 贝壳Shell 闪山灵Opal 缟玛瑙Onyx 形状(Shape) 圆形Round 锥形Taper 马眼形Marquise梨形Pear正方形Square 长方形Rectangle椭圆形Oval 心形Heart 八角形Octagon 三角形Triangle 半圆形Semicircle 类型(Type) 戒指Ring耳环Earring 吊坠Pendant 手镯Bangle 手链Bracelet 项链Necklace 配件Parts 链Chain 呔针Tie Pin呔夹Tie Clip 呔链Tie Chain 呔钉Tie Tack 夹子Clip 套装Set 扣子Clasp 踝饰Anklet 袖口钮Cufflinks发夹Hair Clip 框Frame 笔夹Pen Clip金币Gold Coin 胸针Brooch 一串Strand 锁匙扣Key Holder 雕刻品Carving 条形襟针Stick Pin 表Watch相盒Locket 封底片Plate 瓜子耳Bails 珠子Bead 扣掣Snap款式Style 镶嵌(Setting) 针板镶座Bar setting 包镶Bezel setting 夹镶Channel setting 群镶Cluster setting 吉普赛镶Gypsy setting 隐藏式镶Invisible 密镶式镶Pave setting 爪镶Prong setting 座单石镶Solitaire setting 帝凡尼镶Tiffany setting

国内外八大知名运动品牌实力对比分析

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最全的合金材料缩写

Acron 铝基铜硅合金Adnic 耐蚀铜镍合金 Ajax 铅青铜轴承合金Akrit 钴铬钨刀具合金alader 硅铝合金 Alar 铝硅系合金 Alcres 铁铝铬耐蚀耐热合金Alcumite 铜铝铁镍耐蚀合金aldary 铜合金 Aldrey 铝镁硅合金Alfenol 高导磁铝铁合金alloy content 合金含量 alloy for die casting 压铸合金 alloy material 合金材料 alloy steel rod 合金钢抽油杆 alloy steel 合金钢 alloy 合金 alloyage 制合金;熔合alloying element 合金元素 allumen 锌铝合金 Alneon 铝锌铜合金 ALNI 镍合金钢 Alpax 铝硅合金 ALSI 硅铝合金 Alsical 硅铝钙合金 Alsifer 硅铝铁磁性合金Alsimin 硅铝铁合金

Aludur 铝镁硅合金 aluflex 锰铝合金 Alumel 阿留麦尔镍基合金Alusil 铝硅活塞合金Antaciron 硅铁合金 antifriction alloy 减磨合金 Avional 高拉应力铝合金 BAB 巴氏合金 babbit metal 巴氏合金 babbit packing ring 巴氏合金填密圈 babbit seat 巴氏合金座 babbit 巴比特合金 babbit-lined bearing 巴氏合金衬套轴承babbitting 巴比特合金 Badin metal 巴丁合金 Bahnmetal 铅基轴承合金barberite 铜镍锡硅合金 bearing metal 轴承合金 bendalloy 易熔合金;弯管合金bertholide 贝陀立合金 billon 金、银与其他金属的合金Bonalit 铝基活塞合金Britannia metal 锡锑铜合金 Calite 镍铝铬铁耐热合金Calmalloy 卡尔马洛伊合金Calmet 铬镍铝奥氏体耐热合金calorite 镍铬铁锰耐热合金

Buchwald-Hartwig

Buchwald-Hartwig Cross Coupling Reaction Palladium-catalyzed synthesis of aryl amines. Starting materials are aryl halides or pseudohalides (for example triflates) and primary or secondary amines. The synthesis of aryl ethers and especially diaryl ethers has recently received much attention as an alternative to the Ullmann Ether Synthesis . Newer catalysts and methods offer a broad spectrum of interesting conversions. Mechanism of the Buchwald-Hartwig Coupling Recent Literature

[(CyPF-t Bu)PdCl2]: An Air-Stable, One-Component, Highly Efficient Catalyst for Amination of Heteroaryl and Aryl Halides Q. Sheng, J. F. Hartwig, Org. Lett., 2008, 10, 4109-4112. A Multiligand Based Pd Catalyst for C-N Cross-Coupling Reactions B. P. Fors, S. L. Buchwald, J. Am. Chem. Soc., 2010, 132, 15914-15917. Palladium-Catalyzed Coupling of Ammonia with Aryl Chlorides, Bromides, Iodides, and Sulfonates: A General Method for the Preparation of Primary Arylamines G. D. Vo, J. F. Hartwig, J. Am. Chem. Soc., 2009, 131, 11049-11061. (IPr)Pd(acac)Cl: An Easily Synthesized, Efficient, and Versatile Precatalyst for C-N and C-C Bond Formation N. Marion, E. C. Ecarnot, O. Navarro, D. Amoroso, A. Bell, S. P. Nolan, J. Org. Chem., 2006, 71, 3816-3821.

首饰标记de含义

首饰标志的含义

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