化学试剂--Weinreb酰胺
weinerb 酰胺反应机理 -回复
weinerb 酰胺反应机理-回复酰胺是一类重要的有机化合物，广泛应用于医药、农药、染料和材料科学等领域。
其中，酰胺合成中的关键反应之一就是weinerb酰胺反应，也被称为weiner反应或weiner合成。
1. 简介weinerb酰胺反应是通过醛酮与酰胺基团发生反应，生成酰胺化合物的一种方法。
该反应以其高效、温和和多样性而闻名。
weinerb酰胺反应可利用不同的底物、催化剂和条件来合成各种具有生物活性和药理学意义的酰胺。
2. 反应机理（步骤1）首先，通过醛或酮的羰基碳与底物中的酰胺氮原子形成n-键。
在酸性条件下，氮和羰基之间的质子转移形成亚胺中间体。
（步骤2）此时，亚胺中间体进一步亲核加成攻击底物中的羰基碳，生成稳定的酮型中间体。
这个步骤类似于一般的亲核加成反应，与亚胺的位置有关。
在此步骤中，酰胺中的氮原子充当亲核试剂。
（步骤3）酮型中间体进一步与醛或酮继续进行第二次亲核加成反应。
这一步骤可以重复多次，直到获得所需的酰胺化合物。
3. 催化剂早期的weinerb酰胺反应需要强酸催化剂，如二氯甲磺酸或三氯甲磺酸等。
然而，现代weinerb酰胺反应已经发展出多种选择的催化剂体系。
一种常见的催化剂体系是酸碱型催化剂，如DNA碱基或天然氨基酸。
这种催化剂体系可以在中性条件下进行反应，避免了使用强酸的副作用。
此外，该催化剂体系对于底物的选择性也具有一定的影响。
另一种催化剂是过渡金属催化剂，如钼、铌、钯、铂等。
这些催化剂可以通过配体的选择来调控反应的速度和选择性。
此外，过渡金属催化剂还具有催化复杂底物和亲核试剂的特点。
4. 应用weinerb酰胺反应在有机合成中具有广泛的应用前景。
由于该反应具有高效、温和和多样性的特点，可以为药物发现、生物活性评估和材料科学提供合适的合成方法。
在药物发现中，weinerb酰胺反应可以用于合成具有生物活性的酰胺化合物。
这些化合物可以用于药物库筛选和结构活性相关性研究。
在生物活性评估中，weinerb酰胺反应可以用于合成化合物库，以评估其生物活性和毒性。
有机合成中碳链上增加一个碳原子的方法
有机合成中碳链上增加⼀个碳原⼦的⽅法⼀、以甲醛或甲醛等价物为底物进⾏反应增加碳链1、羟醛缩合反应（Aldol condensation）醛酮在碱性条件下得到烯醇盐和另⼀个羰基化合物缩合得到β-羟基醛酮的反应。
当利⽤甲醛作为底物时则底物增加⼀个碳。
Evans羟醛缩合反应，Abiko-Masamune羟醛缩合反应，Mukaiyama羟醛缩合反应2、Arens-van Dorp反应烷氧基⼄炔在强碱条件下对醛酮加成得到烷氧基炔甲醇的反应。
3、Stobbe condensation丁⼆酸⼆⼄酯及其衍⽣物和羰基化合物在碱性条件下进⾏缩合的反应。
4、Knoevenagel缩合反应羰基化合物和活泼亚甲基化合物在胺催化下缩合的反应。
5、Stetter反应醛和α,β-不饱和酮在噻唑盐的催化下反应制备1,4-⼆羰基化合物的反应。
噻唑盐是氰离⼦的安全替代试剂。
此反应也被称为 Michael-Stetter反应，机理和安息⾹缩合类似。
此反应直接利⽤甲醛作为底物的报道较少，但是有⽂献报道利⽤糖作为甲醛替代物进⾏反应可以得到多⼀个碳的1,4-⼆羰基化合物。
【J. Am. Chem. Soc. 2013, 135, 8113–8116】6、Barbier反应在有机⾦属试剂存在下，羰基化合物可以迅速与其反应，这类反应被称为Barbier反应。
7、Grignard反应（格⽒反应）格⽒反应有多多种⽅式增加碳链，可以考虑以甲醛为底物和格⽒试剂进⾏反应增加⼀个碳链得到醇，也可以以⼆氧化碳为底物进⾏加成得到羧酸，或者直接利⽤甲基格⽒试剂对其他亲电试剂进⾏延长碳链。
8、Kagan-Molander偶联反应9、贝蒂反应(Betti Reaction)酚与芳⾹醛和伯胺作⽤得到 α-氨基苯甲酚类。
这个反应可以视为苯酚的Mannich反应。
10、Mannich反应1903年，B. Tollens和von Marle发现苯⼄酮和甲醛，氯化铵反应可以⽣成三级胺。
酰胺的合成讲解
经典化学合成反应标准操作酰胺及酰亚胺的合成目录1. 前言 (3)2. 羧酸与胺的缩合酰化反应 (3)2.1活性酯法 (3)2.1.1应用氯甲酸乙酯或异丁酯活性酯法合成酰胺示例 (5)2.1.2应用氯甲酸乙酯或异丁酯活性酯法合成伯酰胺示例 (5)2.1.3应用羰基二咪唑合成Weinreb酰胺示例 (6)2.1.4应用的磺酰氯合成酰胺示例 (6)2.1.5应用Boc酸酐合成伯酰胺示例 (7)2.2碳二亚胺类缩合剂法 (7)2.2.1应用DCC缩合法合成酰胺示例 (9)2.2.2应用DIC缩合法合成酰胺示例 (10)2.2.3应用EDC缩合法合成酰胺示例一（二氯甲烷为溶剂） (10)2.2.4应用EDC缩合法合成酰胺示例二（DMF为溶剂） (11)2.3 鎓盐类的缩合剂法 (11)2.3.1应用HATU/TBTU为缩合剂合成酰胺示例 (13)2.3.2应用BOP为缩合剂合成酰胺示例 (14)2.3.3应用PyBOP为缩合剂合成酰胺示例一（常规） (14)2.3.4应用PyBOP为缩合剂合成酰胺示例二（用于合成伯酰胺） (15)2.4 有机磷类缩合剂 (15)2.4.1应用DPP-Cl为缩合剂合成酰胺示例 (16)2.4.2应用DPPA为缩合剂合成酰胺示例 (16)2.4.3应用BOP-Cl为缩合剂合成酰胺示例 (17)2.5.1应用三苯基磷-多卤代甲烷合成酰胺示例 (18)2.5.2应用三苯基磷-六氯丙酮合成酰胺示例 (18)2.5.3应用三苯基磷-NBS合成酰胺示例 (19)3. 氨或胺与酰卤的酰化反应 (19)3.1酰卤的制备示例 (20)3.5.1应用二氯亚砜合成酰氯示例 (20)3.5.2用草酰氯合成酰氯示例 (21)3.5.3用三氯均三嗪合成酰氯示例 (21)3.5.4用三氟均三嗪合成酰氟示例 (22)3.1应用酰卤的合成酰胺 (22)3.5.1应用酰氯合成酰胺示例（有机碱） (22)3.5.2应用酰氯合成酰胺示例（无机碱） (22)3.5.3应用酰氟合成酰胺示例 (24)4. 氨或胺与酸酐的酰化反应 (24)4.2酸酐合成酰胺示例 (25)5. 其他缩合方法 (25)1. 前言酰胺化是有机合成中最基本，也是最重要的合成方法之一。
weinerb 酰胺反应机理 -回复
weinerb 酰胺反应机理-回复"Weinerb酰胺反应机理"是有关有机合成中的重要反应之一，它是通过以酰胺作为底物进行的一个有机化学反应。
本文将详细解释Weinerb酰胺反应的机理，并一步一步回答这个问题。
首先，我们来了解一下Weinerb酰胺反应的定义。
Weinerb酰胺反应是指一类化合物间的反应，其中一个酰胺分子和一个碳酸酯分子在酸性条件下反应生成一种中间体α-酮酸酯的反应。
这个反应机制被广泛应用于有机合成中的关键步骤和中间体的制备。
Weinerb酰胺反应的机理如下：步骤1：质子化在反应开始时，酸性条件下的质子化是触发Weinerb酰胺反应的第一步。
在该步骤中，酸性条件使得碳酸酯和酰胺分子的酰基氧原子上的氢离子化。
这个质子化过程在一个质子酸（如HCl）的存在下发生，它将生成质子化的酰胺阴离子和质子化的碳酸酯阳离子。
步骤2：核机理的生成当质子化发生后，酰胺阴离子中的负电荷将会使氮原子成为一个强亲核试剂。
这会导致亲电的碳酸酯与酰胺阴离子氮原子之间的核机理的生成。
此时，碳酸酯中的羰基碳原子带有部分正电荷，对氮原子的亲电性质起到了吸引和促进作用。
亲核的酰胺阴离子会攻击碳酸酯中的羰基碳原子，从而形成羰基碳原子与氮原子之间的键合。
步骤3：中间体的形成在酰胺阴离子与碳酸酯之间的核机理反应完成后，将会形成一个新的中间体。
这个中间体是一个带有羰基碳原子、酰胺残基和氧原子的中间体。
这个中间体称为α-酮酸酯。
此时，中间体具有两个可能的反应途径。
它可以通过质子化和缩合反应生成酰胺酯，或通过质子化和断裂反应生成酮化合物。
步骤4：产物的生成当中间体形成后，它会进一步发生转化以生成最终的产物。
这可以通过两种不同的方式实现。
首先，中间体可以通过水分子的加入和加热以形成酰胺酯作为产物。
第二，中间体也可以通过碱性条件下的断裂反应而转化为酮化合物。
总结起来，Weinerb酰胺反应机理涉及到四个主要步骤：质子化、核机理的生成、中间体的形成和产物的生成。
经典合成反应标准操作
经典化学合成反应标准操作药明康德新药开发有限公司化学合成部编写前言有机合成研究人员在做化学反应经常碰到常规的反应手边没有现成的标准操作步骤而要去查文献，在试同一类反应时，为了寻找各种反应条件方法也得去查资料。
为了提高大家的工作效率，因此化学合成部需要一份《经典合成反应标准操作》。
在这份材料中，我们精选药物化学中各类经典的合成反应，每类反应有什么方法，并通过实际经验对每类反应的各种条件进行点评，供大家在摸索合成条件时进行比较。
同时每种反应的标准操作，均可作为模板套用于书写客户的final report，这样可以大大节省研究人员书写final report的时间，也相应减少在报告中的文法错误。
另外本版是初版，在今后的工作中我们将根据需要修订这份材料。
药明康德新药开发有限公司化学合成部2005-6-28目录1.胺的合成a)还原胺化b)直接烷基化c)腈的还原d)酰胺的还原e)硝基的还原f)叠氮的还原g)Hoffman降解h)羧酸通过Cris 重排2.羧酸衍生物的合成a)酰胺化的反应b)酯化反应c)腈转化为酯和酰胺d)钯催化的插羰反应e)酯交换为酰氨3.羧酸的合成a)醇氧化b)酯水解c)酰胺的水解d)腈的水解e)有机金属试剂的羰基化反应f)芳香甲基的氧化4.醛酮的合成a)Weinreb 酰胺合成醛酮b)醇氧化c)酯的直接还原d)有机金属试剂对腈加成合成酮5.脂肪卤代物的合成a)醇转化为脂肪溴代物通过PBr3 转化通过PPh3 与CBr4 转化HBr直接交换通过相应的氯代物或磺酸酯与LiBr交换、b)醇转化为脂肪氯代物通过SOCl2转化通过PPh3 与CCl4 转化HCl直接交换c)醇转化为脂肪碘代物通过PPh3 与I2 转化通过相应的氯代物或磺酸酯与NaI交换6.芳香卤代物的合成a)Sandermyyer 重氮化卤代b)直接卤代c)杂环的酚羟基或醚的卤代7.醇的合成a)羧酸或酯的还原b)醛酮的还原c)卤代烃的水解.d)吡啶的氧化转位8.酚的合成a)Sandermayer 重氮化反应b)醚的水解c)Bayer-vigerlar 氧化d)硼酸的氧化9.腈的合成a)磺酸酯或卤代烃的取代b)酰胺的脱水c)芳卤代烃的氰基取代10.硝化反应11.醚的合成a)芳香醚的合成酚与烷基卤代烃的直接烷基化Mitsunobu 芳香醚化Buckwald芳香醚化b)脂肪醚的合成醇的醚化12.脲的合成a)胺与异腈酸酯的反应b)用三光气合成脲c)羰基二咪唑（CDI）合成脲d)对硝基苯酚碳酰胺合成脲.13.烯烃的合成a)Wittig 反应b)羟基的消除c)Wittig-Horner 反应合成α,β-不饱和酯14.磺酸及磺酰氯的合成a)氯磺化反应合成磺酰氯b)从硫醇合成磺酰氯c)磺化反应15.氨基酸的合成a)Streck 反应合成b)手性氨基酸的合成16.偶联反应a)Suzuki Couplingb)Buckwald 芳胺化，芳酰胺化、c)Heck 反应17.Mitsunobu 反应a)醇的反转b)胺的取代18.脱羟基反应19.酮还原为亚甲基.20.氨的保护及脱保护策略a)用碳酰胺作保护基b)苄基保护21.醇的保护及脱保护策略a)用硅醚进行保护b)其他醚类保护22.羧基的保护Boc脱保护-------------------------------------------------------------------------------------------------------1格氏反应---------------------------------------------------------------------------------------------------------1 还原胺化---------------------------------------------------------------------------------------------------------2卤化反应---------------------------------------------------------------------------------------------------------2 Suzuki coupling-------------------------------------------------------------------------------------------------2 磺化反应---------------------------------------------------------------------------------------------------------3 酯化反应---------------------------------------------------------------------------------------------------------3 水解反应---------------------------------------------------------------------------------------------------------3 硝化反应---------------------------------------------------------------------------------------------------------4 n-BuLi------------------------------------------------------------------------------------------------------------4 LiAlH4还原-----------------------------------------------------------------------------------------------------4 POCl3的杂环氯代----------------------------------------------------------------------------------------------5 NaH---------------------------------------------------------------------------------------------------------------5 NBS---------------------------------------------------------------------------------------------------------------5 氢化反应---------------------------------------------------------------------------------------------------------6 m-CPBA----------------------------------------------------------------------------------------------------------6 EDC---------------------------------------------------------------------------------------------------------------6 用三光气成脲---------------------------------------------------------------------------------------------------7 芳卤用n-BuLi处理后与Weinreb酰胺成酮-----------------------------------------------------------------7Boc 上保护OHH 2NHO OOO OOO OHN HO OHO O A BTo a solution of A (2.72 g, 13.9 mmol) and tetramethylammonium hydroxide pentahydrate (5.62 g, 31.0 mmol) in acetonitrile (270 mL) was added di-tert-butyldicarbonate (3.79 g; 17.4 mmol) and the resulting solution was allowed to stir 18 h at rt and concentrated. The residue was partitioned between Et2O/H2O; the phases were separated and the aqueous phase extracted twice more with Et2O. The aqueous phase was brought to pH 4 with solid citric acid and extracted with CHCl3 (3.x.100 mL). The organic extracts were combined, dried (Na2SO4) and concentrated to afford 2.58 g (63 percent) B as a white foam.ReturnBoc 脱保护OON HOO OOH 2NTert-Butyl 2-(2-methoxyphenoxy)ethylcarbamate (23.8 g, 89 mmol) in dichloromethane (10 ml) was cooled to 0 deg C and stirred as a mixture of trifluoroacetic acid: dichloromethane (1:1, 40 ml) was added dropwise. The mixture was allowed to warm to rt, stirred for 2 hours and concentrated in vacuo. The residue was taken back up in dichloromethane (100 ml) and the solution was washed with saturated aqueous sodium hydrogen carbonate (3*20 ml) and aqueous sodium hydroxide (10percent, 3*20 ml), dried (Na2SO4), filtered and concentrated in vacuo to provide 2-(2-methoxyphenoxy)ethylamine (13 g, 88percent yield) as a light yellow solid.Return格氏反应NCNNOA stirred mixture of magnesium turnings (23.6 g, 0.98 mol) and Et2O (200 mL) under nitrogen is treated with a crystal of iodine and about 5percent of a solution of bromoethane (56.3 ml, 0.75 mol) in Et2O (375 mL). When the reaction starts, the remainder of the bromoethane solution is added, dropwise at a rate sufficient to maintain a gentle reflux. After the addition, stirring is continued for 1 hour. To this solution ofethylmagnesium bromide was slowly added a solution of 4-cyanopyridine (39 g, 0.375 mol) in Et2O (750 ml). The reaction mixture was warmed at reflux for 12 hours, treated with concentrated H2SO4 (125 ml)/H2O (125 ml), and then washed three times with Et2O (250 ml). The aqueous portion was made basic (PH 9) with 15percent NaOH solution and extracted five times with 250 ml portions of Et2O. The combined Et2O extracts were dried (MgSO4), and the solvent was removed under reduced pressure to afford a brown oil (48.4 g, 95percent).Return还原胺化OHO H 2N+HON HA solution of 2-amino-4-ethylphenol (1.00 g. 7.28 mmol), 2-naphthaldehyde (1.13 g, 7.28 mmol), and p-toluenesulfonic acid (0.05 g) in methanol (50 ML) was stirred at room temp for 24 h. To the resultant solution, sodium borohydride (0.82 g, 22 mmol) was added in small portions. After addition was completed, the mixture was stirred at room temperature for 30 min and concentrated under vacuum. The residue was then subjected to column chromatography on silica gel eluted with 10percent ethyl acetate in hexane and followed by recrystallization (aqueous methanol) yielded 450 mg (22percent) of analytically pure product.Return卤化反应O 2NO 2NBrTo a stirred solution of 8-methyl-1-nitro-naphthalene (10.6g, 56.32 mmol) and iron (III) chloride (0.45 g, 2.77 mmo) in CCl4 (150 ml) heated to 60°C was added dropwise (3.0 ml, 58.23 mmol) of bromine. After one hour, the reaction mixture was poured into saturated NaHCO3 solution, and the layers were separated. The aqueous layer was re-extracted with CH2Cl2. The combined organic layers were dried (MgSO4) and the solvent was removed under reduced pressure. The crude residue was recrystallized from ethanol and the mother liquors were concentrated and then flash chromatographed on silica, eluding hexanes:ethyl acetate (12: 1).Return Suzuki couplingBrBOO NH+NH To a mixture of 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-indole (2 g, 8.2 mnmol) and3-bromobenzene (0.87 ml, 8.3 mmol) in THF (28 ml) were added palladium catalyst Pd(PPh3)4 (284 mg, 0.25 mmol) and the freshly prepared sodium hydroxide solution (984 mg in 9 ml of water).The system was degassed and then charged with nitrogen for three times. The mixture was stirred under nitrogen at 70 °C oil bath for 6 hours. The reaction solution was cooled to room temperature, diluted with ethyl acetate and separated from water layer. The ethyl acetate solution was washed by brine, dried over Na2SO4 and concentrated. The residue was purified on a silica gel column eluding with hexanes: EtOAc 9:1 to give 1.38 g (78%yield) of 4-phenyl-1H-indole as a colorless liquid.Return 磺化反应NOFFFNOFFFSOClOChlorosulfonic acid (4.66g, 40 mmol) is added dropwise to a cold (0°C) solution of2,3-dihydro-2-trifluoroacetyl-1H-Benz[de]isoquinoline (2.9g, 8 mmol) in chloroform (800 ml). The resulting solution is stirred at 0°C for 30 minutes. The cold bath is then removed and the solution is stirred at room temperature for 1 hour then cautiously poured into ice water. The organic layer is separated, dried over magnesium sulfate and concentrated to afford the title compound. The crude product is purified by column chromatography eluted with 10% acetic ether in petroleum ether (2.36 g, 81% yield).Return酯化反应HOHO O HOOOA mixture of 4-hydroxymethylnaphthoic acid (10 g, 50 mmol), methanol (300 ml), and concentrate H2SO4 (2 ml) was refluxed overnight. The insolubles were filtered off and the filtrate was concentrated. The residue was taken up in ethyl acetate and washed with aqueous NaHCO3 (2*), brine, dried over MgSO4, and concentrated to give a yellow oil. Silica gel column chromatography using ethyl acetate/hexane (1/3) gave the desired product as a yellow oil (3.3 g, 35%yield).Return水解反应OO OHOA solution of 1-Methyl-naphthalene-2-carboxylic acid methyl ester (7.20g, 35mmol) and 2N sodium hydroxide (35ml) in tetrahydrofuran (130ml) was stirred under reflux for 18 hours. The mixture was neutralised using 2N hydrochloric acid, and extracted with dichloromethane (3x). The combined organic solutions were dried (MgSO4), and evaporated under reduced pressure. The crude product was purified by column chromatography on silica gelusing an elution gradient of dichloromethane: methanol (100:0 to 97:3) to afford the title compound as a solid (3.11g, 47.8%yield).Return硝化反应2To a cold (0°C) suspension of 1-methylnaphthalene (5 g, 35.2 mmol) in HNO3 was added H2SO4 (5 ml)dropwise. After stirring the reaction for one hour, the solution was diluted with ethyl acetate and washed with water (3*), aqueous saturated NaHCO3 (2*) and brine, dried over MgSO4, and concentrated. The product was purified by silica gel column chromatography using ethyl acetate: hexane (5: 95) and recrystallized from methanol to give yellow needles (0.22g, 33% yield).Returnn-BuLiEtOCF 3O CF 3O NCTo a dry three-necked round-bottomed flask with an addition funnel and at -78°C under inert atmosphere was charged with anhydrous THF (500 ml). A solution of n-butyllithium (2.5 M in hexane, 88 ml, 220 mmol) was added dropwise followed by addition of a solution of acetonitrile (10.43 ml, 200 mmol) in anhydrous THF (100 ml). The internal temperature was maintained below -70°C during the entire addition process. After 2 hr at -78°C a solution of Trifluoro-acetic acid ethyl ester (14.2 g, 100 mmol) in anhydrous THF (30 ml) was added dropwise and the mixture was stirred for 1.5 hr. To the mixture was added acetic anhydride to quench the reaction. The reaction mixture was allowed to warm up to rt. A precipitate was filtered and the filtrate was concentrated to give a brown oil, which was used in the next step without purification.ReturnLiAlH4还原HOHO O HOHOA solution of 2,3-naphthalenedicarboxylic acid (4.6 g, 0.023 mole) in dry THF (135 ml, warmed to 50° to maintain solution) is added dropwise over 15 minutes to a 1.15 M lithium aluminum hydride solution in THF (45 ml, 0.052 mole). The solution is stirred 3 hours after which TLC indicated consumption of diacid and formation of a new major product. The reaction is quenched carefully with THF-water, then 2N hydrochloric acid (40 ml) is added, and the resulting mixture is extracted 3 times with ether. The combined ether extracts are washed with water (2 times), with saturated sodium bicarbonate solution (1 time), with water, and are dried (sodium sulfate), filtered, and concentrated to give a tan solid (3.67 g). The solid isrecrystallized from ethyl acetate giving the title compound (2.91 g, 67.3%yield) as a light tan crystalline material.ReturnPOCl3的杂环氯代NNHOOH NClClTo a suspension of 2,4-dihydroxy-5,6-dimethylpyrimidine (6.2 g, 0.044 mol) in POCl3 (25 ml) was slowly added N,N-dimethylaniline (6.18 ml, 0.049 mol). The mixture was then refluxed at 125 °C for 3 hours. After this time, the starting material completely dissolved indicating that the reaction was completed.The reaction mixture was cooled and then poured slowly onto ice to quench the POCl3(caution[exothermic]). A precipitate formed, which was filtered and washed with ice-cold water. The precipitate was dried under high vacuum overnight to yield 2,4-dichloro-5,6-dimethyl-pyrimidine (7.2 g, 0.041 mol, 92%yield) as a yellow solid.ReturnNaHHSH 2N Cl+SNH 2Sodium hydride (50% in mineral oil, 5.5 g, 0.11 mol) was added portionwise at 0 °C under a nitrogen atmosphere to a solution of 2-aminobenzenethiol (12 ml, 0.1 mol) in DMF (120 ml). After 0.5 h, benzyl chloride (11.5 ml, 0.1 mol) in DMF (80 ml) was added in 0.5 h. The solution was stirred for 3 h while the temperature was allowed to rise to rt, then it was poured into ice/water (1000 g). The precipitate was filtered, dissolved in ethyl acetate and washed with brine. The organic layer was dried over Na2SO4 and evaporated. The solid obtained was ground in pentane (19.3 g, 90% yield).ReturnNBSN NFClCl NBSNNFClClBrA mixture of 2,4-Dichloro-6-ethyl-5-fluoro-pyrimidine (27.46 g，0.14mol), AIBN (1.32 g) and n-bromosuccinimide (27.02 g，0.152mol) in CH2Cl2 (170 ml) was refluxed under a nitrogen atmosphere for 36 h. Then washed by water, the aqueous was extracted by CH2Cl2. The combined organic layer was washed by saturated Na2S2O3 and brine, dried over Na2SO4, and evaporated to give a white solid which was purified by column chromatography eluted with 50% acetic ether in petroleum ether (34 g, 88.6% yield).Return 氢化反应O ONH OONH2Cl ClA mixture of ethyl 3-(N-benzylamino)-3-methylbutyrate hydrochloride (25g, 0.1 mol) and 10percent Pd-C (2g) in 250 ml of dried alcohol was hydrogenated under 55 psi H2 for four days. The reaction medium was then filtered and evaporated under reduced pressure to provide an amber oil which gradually crystallized upon standing (18 g, 100% yield).Returnm-CPBAS NH2SNH2OA solution of 85% m-chloroperoxybenzoic acid (19 g, 94 mmol) in CH2Cl2 (350 ml)was added at –5 –0 °C to a solution of 2-Benzylsulfanyl-phenylamine (19 g, 88 mmol) in CH2Cl2 (400 ml). The mixture wasallowed to warm to rt in 3 h, then it was washed with a 5% Na2S2O3 solution, 10% NaHCO3 solution and brine. The organic layer was dried over Na2SO4, and evaporated. The solid was ground in pentane (19 g, 95% yield).ReturnEDCNH 2O+H OTo a 0°C mixture of Boc-L-tyrosine (2.04 g, 7.26 mmol) and amylamine (0.63 gl, 7.26 mmol) in methylene chloride (30 ml) is added 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC) (1.53 g, 9.9 mmol). The white mixture is stirred at 0°C for 5 min and at room temp for 23 hrs. The resulting solution is diluted with methylene chloride (30 ml) and washed successively with 0.5 M HCl (40 ml), water (20 ml) and sat aq sodium bicarbonate (25 ml). The organic phase is dried over magnesium sulfate and concentrated to a foam (1.84 g, 72.4%yield), sufficiently pure to carry into the next step. An analytical sample is obtained by HPLC.Return三光气成脲NH 2ONO 2Si O Cl ClO Cl ClO 2NHN H NOHOHNO 2+To a solution of 2-(tert-butyldimethylsilyloxy)-4-nitroaniline (200 mg, 0.75 mmol) in toluene (10 ml) triethylamine (0.13 ml, 1.64 mmol) and triphosgene (88.4 mg, 0.3 mmol) were added. The reaction mixturewas stirred at 70 °C for 2 hours, then cooled to room temperature. Then more 2-(tert-butyldimethylsilyloxy)-4-nitroaniline (200 mg, 0.75 mmol) was added. The resulting mixture was allowed to stir at 70 °C for 48 hours then cooled to room temperature. The reaction mixture was partitioned between water and ethyl acetate. The combined organic phase was washed with brine, dried over MgSO4 and filtered. Removal of solvent at reduced pressure and chromatography of the resulting oil on silica gel (hexane: ethyl acetate, 10:1) gave 1,3-Bis-(2-hydroxy-4-nitro-phenyl)-urea (130 mg, 31%yield).Return芳卤用n-BuLi 处理后与Weinreb 酰胺成酮N F FFN O O+F FF ONFTo a solution of diisopropylamine (17.69 ml, 0.135 mole) in THF (200 ml) at –78°C under argon wasadded n-butyllithium (54.0 ml, 2.5M in hexane, 0.135 mole), followed after 5 min by dropwise a solution of 2-fluoro-4-methylpyridine (10 g, 0.090 mole) in THF (20 ml). After stirring for 15 min at –78°C, a solution of N-methoxy-N-methyl-3-trifluoromethylbenzamide (23.08 g, 0.099 mole) in THF (10 ml) was added dropwise. After stirring for more 5 min, the reaction was allowed to warm to 0°C and quenched by pouring into water (400 ml) and ethyl acetate (400 ml). The layers were separated, and the aqueous layer washed with ethyl acetate (200 ml). The ethyl acetate extracts were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to an oil which was chromatographed on silica gel with 20percent ethyl acetate in hexane to give 21.6 g of 2-(2-Fluoro-pyridin-4-yl)-1-(3-trifluoromethyl-phenyl)-ethanone (84.8%yield).Return。
Weinreb酰胺的制备及应用研究进展
学年论文题目： Weinreb酰胺的制备及应用研究进展学院：化学化工学院专业： 11级化学（师范）指导教师：学生姓名学号：2014年 5月 30日目录摘要------------------------------------------------------------------------------第3页关键字---------------------------------------------------------------------------第3页1.Weinreb酰胺简介------------------------------------------------------第3页2.Weinreb酰胺的合成方法：-------------------------------------------第4页2.1有机锌试剂制备weinreb酰胺的方法------------------------第4页2.2以羧酸为原料的合成法-----------------------------------------第5页2.3以羧酸酯为原料的合成法----------------------------------------第6页2.4以酰氯为原料的合成法-------------------------------------------第6页2.5以酰胺为原料的合成法-------------------------------------------第7页3. weinreb酰胺的应用进展----------------------------------------------第7页3.1用weinreb酰胺合成酮---------------------------------------------第7页3.2weinreb酰胺还原反应--------------------------------------------第7页3.3weinreb酰胺水解反应--------------------------------------------第8页4.总结：-------------------------------------------------------------------------第8页参考文献：---------------------------------------------------------------------第8页Weinreb酰胺的制备及应用研究进展摘要：Weinreb酰胺是一类十分重要的酰基化试剂，在许多天然产物的合成中有着的广泛的应用，其合成的方法有很多种，在此介绍羧酸、羧酸酯、酰氯、酰胺为原料和用有机锌试剂制备weinreb酰胺的方法。
weinreb酰胺的制备
weinreb酰胺的制备
Weinreb酰胺是一种重要的羰基合成试剂，可以用于合成酮和醛化合物。
下面是Weinreb酰胺的制备方法：
1. 材料：
- N，N-二甲基甲酰胺（DMF）
- 三氯甲烷（CHCl3）
- 碳酸二甲胺（DMA）
- 甲酸
- 二甲基氨基乙基氯化铜（CuCl2·2DMF）
2. 实验步骤：
a. 准备一个干净的干燥的反应瓶，用氮气干燥瓶内空气。
b. 向瓶中加入DMF（1.2当量），然后加入三氯甲烷（2.2当量）。
c. 向瓶中加入碳酸二甲胺（1当量）。
d. 将甲酸（1当量）添加到瓶中。
e. 加入二甲基氨基乙基氯化铜（0.1当量）。
f. 将反应瓶密封，并在室温下搅拌反应约24小时。
g. 完成反应后，用水稀释反应混合物，并用氯化钠饱和。
h. 用冷水洗涤有机相，然后使用氯化钠饱和水溶液洗涤，最后用氯化钠饱和溶液洗涤。
i. 使用旋转蒸发仪将有机溶剂蒸发掉，得到Weinreb酰胺产物。
j. 需要根据具体的实验需求进行进一步纯化和抽提等操作。
请注意，这只是Weinreb酰胺的一种制备方法，实际操作中可
能还会有其他变体的方法。
此外，在操作化学试剂时，请严格遵循操作规程和实验室安全指南。
卤代酮的合成-060123
经典化学合成反应标准操作α-卤代酮的合成目录1．前言 (2)2. 直接卤化 (2)3．经重氮酮制备 (4)4．从weinreb 酰胺制备 (6)5．傅克酰基化合成卤代酮 (7)6 其他合成α-卤代酮的方法 (9)1．前言α-卤代酮的合成广泛应用于现代有机合成中， 多用于溴的烷基化、合成咪唑及噻唑等杂环类化合物，其合成方法常用直接卤化、经重氮酮制备、经Weinreb 酰胺制备、傅克酰基化等方法合成。
2. 直接卤化酮的α-氢易被取代，可以直接合成α-卤代酮。
一般操作是将酮与卤素于醋酸、氯仿、DMF 或水中反应。
除卤素外， 硫酰氯、五卤化磷、过溴化吡啶氢溴酸盐（C5H5NH.Br 3）、三卤化三甲基苄基铵盐等也可以做卤化试剂。
对称酮或只有一个取代方向的酮卤代时，可以良好产率（80~90%）生成α-卤代酮。
不对称酮卤代，往往生成α-及α’-卤代酮的混合物。
由于酮卤代的决定步骤是酮的烯醇化，因此，易形成烯醇的方向优先卤代。
例 2-甲基环己酮与亚硫酰氯作用， 多取代的α-氢优先氯代1。
OCH 3OCH 3Cl 2485%若利用双（二甲基乙酰胺基）三溴化氢做溴化剂，可使不对称酮在少取代一边溴代2。
OOBr[(Me 2NCOCH 3)2H]Br 3384%若将不对称酮首先转变成为一定构型的烯醇盐，继而卤代，是区域定向卤代的新方法3。
OH 3COH 3CCl1. i -Pr 2NLi, THFPhCOOEtO CH 3PhOCH 3Br 1. NaH, DMSO另外，甲基酮可用甲基格式试剂与相应的Weinreb 酰胺来制备， 如下例即是先合成甲基酮，后溴化来合成α-溴代酮的4。
NBocO HONBocO NO NBocODCC, D MAP, N HMeOMe MeMgI , e t h er合成实例一 5OOOOOOBrBr 2, AcOH2B 2AA suspension of ketone 2A (700 mg, 2.17 mmol) in acetic acid (15 ml) was heated to 70℃, followed by addition of bromine (347 mg, 2.17 mmol). After the mixture was stirred at 70℃ for 3h, the solvent was evaporated and the residue was purified by column chromatography to give the compound 2B (591 mg, 68%).合成实例二6OMe MeOO Br OMeMeOOBr232C2DBromine (7.99 g, 50 mmol) in CHCl 3 (20 ml) was added in a dropwise manner to a stirred solution of 2, 5-dimethoxy-4-bromoacetophenone 2C (12.95 g, 40 mmol) in CHCl 3 (100 ml) at 5℃. After the addition was completed, the reaction mixture was allowed to warm to room temperature and stirred for an additional 2 h. The mixture was poured onto crushed ice, the organic portion was separated and washed with water, saturated NaHCO 3 solution, and again with water. The solution was dried MgSO 4, and evaporated to dryness under reduced pressure to give a crude product. The product was recrystallized from MeOH to yield 14.70 g (87%) of the desired bromoacetophenone 2D as a white solid.ON NH 2NON NH 2NBr AcOH, 48% aq. HBr and Br 2To a solution of 1-(2-aminopyrimidin-4yl) ethanone (412 mg, 3 mmol) in glacial acetic acid (1 mL) and 48% aq. HBr (0.3 mL), bromine (0.153 mL) in acetic acid (0.4 mL) was added and the resulting orange solution was stirred at RT for1.5 hours. After diluting with ethyl acetate (15 mL), the precipitate was filtered and washed with ethl acetate thus affording the target compound as a whitish solid (580 mg, 65%).合成实例四8O OSiOOSi Br 2E 2FBenzyltrimethylammonium tribromide (4.17 g, 10.7 mmol) was added to a solution of Compound 2E (4.00 g, 10.7 mmol) in CH 2Cl 2-MeOH (5:2, 25 mL). The mixture was stirred at RT for 3 h. At this time the reaction mixture was concentrated in vacuo and H 2O (15 mL) was added. The mixture was extracted with diethyl ether (3 × 20 mL). The combined organic extracts were washed with brine (15 mL), dried over MgSO 4, filtered and concentrated in vacuo. The residue was purified by silica gel chromatography (hexanes:EtOAc, 3:1) to afford to afford Compound 2F (3.97 g, 8.8 mmol, 82%) as a thick yellow oil.3．经重氮酮制备不对称酮卤代时，有时无法得到单卤代产物。
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N-甲基-N-甲氧基酰胺，又称Weinreb酰胺(WAs)，是一种被广泛应用于有机合成中的酰基化试剂。
Weinreb酰胺既可与格氏试剂或有机锂试剂反应合成酮，也可经金属氢化物还原成醛，且金属试剂过量不会导致产品过度加成。
此外，Weinreb酰胺具有易制备、稳定易存储，可放大反应的优势。
制备
Weinreb酰胺一般可通过羧酸活化、羧酸衍生物（酰卤、酯、内酯、酰亚胺、酸酐、醛等）与N,O-二甲基羟基胺盐酸盐（DMHA）缩合、三氯甲基醇经同系化-胺化反应等制备。
近年来，也有报道，过渡金属Pd催化合成反应也可合成乙烯基或芳基WAs。
主要反应
Weinreb酰胺在合成中最重要的应用就是通过WAs能与各种金属有机试剂反应得到醛酮，且该反应中金属离子可与WAs的羰基氧和甲氧基氧形成稳定的螯合环，因此不会发生过度加成（反应机理详见下图）。
其中，Weinreb酰胺还能参与Wittig反应和Shapiro反应制得醛酮。
此外，在一些反应中，WAs会发生脱甲氧基副反应，即N-O键发生断裂的现象，导致WAs分解。
常用的Weinreb酰胺列表。