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1、經(jīng)典合成反應(yīng)標(biāo)準(zhǔn)操作鈀催化的插羰反應(yīng) 藥明康德新藥開發(fā)有限公司經(jīng)典化學(xué)合成反應(yīng)標(biāo)準(zhǔn)操作鈀催化的插羰反應(yīng)編者:錢占山藥明康德新藥開發(fā)有限公司化學(xué)合成部Contents1 前言2-32 插羰反應(yīng)制備羧酸及其衍生物4-153 插羰反應(yīng)制備羧酸實(shí)驗(yàn)操作15-164 插羰反應(yīng)制備羧酸酯實(shí)驗(yàn)操作16-195 插羰反應(yīng)制備酰胺實(shí)驗(yàn)操作19-206 插羰反應(yīng)制備醛207 插羰反應(yīng)制備醛實(shí)驗(yàn)操作21-228 插羰反應(yīng)制備酮22-309 插羰反應(yīng)制備酮實(shí)驗(yàn)操作30-311. 前言在有機(jī)合成中,鈀催化的反應(yīng)是一類特別有用的反應(yīng),它提供了一種形成碳-碳鍵的獨(dú)特的方法。這類反應(yīng)的優(yōu)點(diǎn):1、不需要加入其他氧化劑催化;2、

2、只需催化量的鈀催化劑。鈀催化的插羰反應(yīng)是這類反應(yīng)中應(yīng)用最為廣泛的反應(yīng)之一,在這里我們將重點(diǎn)介紹它。眾所周知,在格氏反應(yīng)中單質(zhì)鎂金屬與帶有sp3雜化碳原子的有機(jī)鹵化物(烷基鹵化物)反應(yīng)要比帶有sp2雜化碳原子的有機(jī)鹵化物(芳基和烯基鹵化物)反應(yīng)更容易。而與此相反,鈀的絡(luò)合物與含有sp2雜化碳原子的有機(jī)鹵化物反應(yīng)更容易。換句話說,烯基和芳基鹵化物非常容易與Pd(0)發(fā)生氧化加成反應(yīng),從而生成含有鈀-碳-鍵的絡(luò)合物中間體1;然后,不飽和化合物(例如:烯烴、共軛二烯、炔烴和一氧化碳等)插入到鈀-碳鍵之間;最后,經(jīng)過還原消去或者-氫消去反應(yīng)生成相應(yīng)的目標(biāo)化合物。與此同時(shí),Pd(0)催化劑得以再生并開始新

3、的催化循環(huán)。由此可見,正是因?yàn)樯闪诉@種含有鈀-碳-鍵的絡(luò)合物中間體,才使得接下來的插入和金屬轉(zhuǎn)移過程變成可能。實(shí)驗(yàn)證明,Pd的配合物比較容易與碘化物和溴化物發(fā)生氧化加成反應(yīng)。碘化物可以在不加入任何膦配體的條件下,只用Pd(dba)3、Pd(OAc)2甚至是Pd/C作催化劑即可發(fā)生反應(yīng)。而溴化物的反應(yīng)一般是需要膦配體的。但是氯化物在一般的條件下是非常惰性的,只有用較強(qiáng)給電子性的具有雙配位基(bidentate)的配體(如dppp),同時(shí)在非常劇烈的條件下才能發(fā)生反應(yīng)。例如氯苯的鈀催化反應(yīng)往往要加入Cr(CO)3,目的是利用它的強(qiáng)吸電子性活化Cl-C鍵。應(yīng)該指出的是,為了中和反應(yīng)生成的HX酸,堿

4、(R3N、NaOAc、KOAc、Na2CO3、K2CO3等)的使用是必需的。除了鹵化物以外,類鹵化物R-X = ArCO-Cl, ArSO2-Cl, Ar-N2+X-, R-OP(O)(OR)2, R-OSO2CF3 (OTf), R-OSO2Rf (Rf = perfluoroaikyl), R-OSO2F, R-OSO2CH3和Ar-ArI+是很好的離去基團(tuán),它們也能與Pd(0)發(fā)生氧化加成反應(yīng)從而形成芳基和烯基鈀配合物中間體。但是,這些離去基團(tuán)對于Pd(0)的反應(yīng)活性是各不相同的,它們中的某些化合物往往只能和某些特定的底物在非常特殊條件下發(fā)生反應(yīng)。最有用的類鹵化物是酚的三氟甲磺酸芳基酯和

5、從羰基化合物派生出來的三氟甲磺酸烯醇酯。芳?;u化物和磺?;u化物通過先與Pd(0)發(fā)生氧化加成反應(yīng),緊接著脫去CO和SO2就形成了芳基鈀配合物。另外,苯的重氮鹽是形成芳基鈀配合物的最活潑反應(yīng)源。烷基鹵化物和Pd(0)的氧化加成反應(yīng)是非常緩慢的。而且,通過烷基鹵化物的氧化加成反應(yīng)得到的烷基鈀配合物經(jīng)過-氫消除之后,反應(yīng)就停止在這一階段,而不再進(jìn)行插入或金屬轉(zhuǎn)移過程。對于炔基鹵化物來說,雖然沒有太多的文獻(xiàn)報(bào)道,但是炔基碘化物的確可以和Pd(0)反應(yīng)生成炔基鈀配合物。2. 插羰反應(yīng)制備羧酸及其衍生物芳基和烯基鹵化物在溫和條件下的鈀催化插羰反應(yīng)是合成羰基化合物的非常有用的合成方法。反應(yīng)機(jī)理是芳基和烯

6、基鹵化物先和Pd(0)發(fā)生氧化加成反應(yīng)生成芳基或烯基鈀配合物,然后CO插入到鈀-碳鍵之間,最后在醇或水等試劑的親和進(jìn)攻下就形成了相應(yīng)的酯或羧酸。芳香的或,不飽和的羧酸或酯就是芳基或烯基鹵化物在水或醇中通過插羰反應(yīng)制得的。在玉米烯酮2-4的全合成中,酯2-3是通過基團(tuán)密集的芳基碘化物2-1的插羰反應(yīng)制得的。然而醇分子2-2中的烷基碘部分是不參與反應(yīng)的。三氟甲基丙烯酸甲酯2-6 被制備是通過3,3,3-三氟-2-溴丙烯的插羰反應(yīng)。這個(gè)羰基化反應(yīng)在烷基尿素存在下就生成化合物2-7,它可以進(jìn)一步被轉(zhuǎn)化成三氟甲基尿嘧啶2-8。這是個(gè)非常有價(jià)值的反應(yīng)。在通常情況下,碘化物和溴化物常被用于插羰反應(yīng),而氯化物

7、是非常惰性的。但是,在使用雙配位基膦(bidentate phosphine)的條件下,芳基氯化物的氧化加成反應(yīng)可以順利進(jìn)行。因?yàn)殡p配位基膦可以和鈀形成一個(gè)六元環(huán)螯合物結(jié)構(gòu),這樣就增強(qiáng)了鈀的電子云密度。舉個(gè)例子,苯甲酸可以通過氯苯的羰基化反應(yīng)合成,但是這個(gè)反應(yīng)必須要用bis(diisopropylphosphine)propane 2-9(dippp)作為配體,在150oC高溫條件下進(jìn)行。另外,tricyclohexylphosphine被用于芳基鹵化物在氫氧化鉀水溶液等兩相條件下的插羰反應(yīng)也是可取的。碘苯的衍生物在H2O/DMF(1:1)的混合溶劑中,不加任何膦配體在室溫和1atm壓力下就可

8、以進(jìn)行插羰反應(yīng)生成苯甲酸的衍生物2-10。在利用插羰反應(yīng)合成鄰氨基苯甲酸衍生物2-10的過程中發(fā)現(xiàn),反應(yīng)物鄰溴苯胺衍生物上的氨基被乙?;Wo(hù)對插羰反應(yīng)是至關(guān)重要,這也許是螯合效應(yīng)的緣故。在鹵化物的插羰反應(yīng)中,有時(shí)需要鈀催化劑和相轉(zhuǎn)移催化劑合用來催化反應(yīng)。1,1-二溴烯烴2-12在相轉(zhuǎn)移催化劑BnNEt3Cl的作用下成功的合成出不飽和二羧酸2-13。在此反應(yīng)中,極性溶劑的使用是非常重要。醇2-14用Pd(OAc)2和Ph3P作催化劑在甲苯溶劑中插羰可以得到內(nèi)酯2-15。有趣的是,在此反應(yīng)中加入Me3SiCl(2 equiv.)可以非常明顯提高反應(yīng)收率。甲酸酯可以代替CO作為插羰反應(yīng)的羰基源,它常

9、和NaOR一起用于插羰反應(yīng)。碘苯在氮?dú)獗Wo(hù)下,用PdCl2(Ph3P)2作催化劑,與甲酸甲酯和甲醇鈉反應(yīng)制得苯甲酸甲酯。氯苯在Cr(CO)3活化下可以與甲酸乙酯發(fā)生插羰反應(yīng)。芐氯插羰可以得到苯乙酸酯。芐氯在兩相溶劑(水和庚烷)中用水溶性的磺化的膦化物作為配體(water-soluble sulfonated phosphine,DPMSPP)通過插羰反應(yīng)以較高的收率(89%)制得苯乙酸2-16。在一個(gè)大氣壓下,通過用triethylbenzylammonium chloride作為相轉(zhuǎn)移催化劑,芐氯和叔丁醇插羰反應(yīng)可以制備苯乙酸叔丁酯。芐基鹵化物的插羰反應(yīng)還可以在中性的的條件下進(jìn)行,例如使用分

10、子篩、四甲基尿素等。在大環(huán)內(nèi)酯彎孢霉菌素2-20的全合成中,酯2-19的制備就是在這種中性的條件下通過芐基氯化物的鈀催化插羰反應(yīng)而獲得的。雖然絕大多數(shù)的醋酸芐酯不能應(yīng)用于插羰反應(yīng),但是手性化合物1-和2-(1-acetoxymethy)naphthalenes 2-21可以進(jìn)行插羰反應(yīng)的,它在HCO2Na和dppp的條件下通過formate-mediated carbonylation得到羧酸2-22和2-23(84:16)。同樣,相應(yīng)的1-naphthylethyl formate也能進(jìn)行插羰反應(yīng)。苯乙酸衍生物2-25也可以由帶有給電子基團(tuán)的芳香醛2-24通過插羰反應(yīng)獲得。這個(gè)反應(yīng)要在110

11、oC,50-100 atm(CO)壓力和Pd-Ph3P-HCl的催化體系中進(jìn)行。此反應(yīng)的可能機(jī)理如下所示:三氟甲磺酸苯酚酯用Ph3P作為配體插羰可以制得芳香酸酯。如果這個(gè)反應(yīng)改用dppp作為配體,反應(yīng)速度可以提高500倍。這個(gè)反應(yīng)是由苯酚制備苯甲酸酯和由萘酚制備萘甲酸酯2-26的非常好的方法。軸手性化合物1,1-聯(lián)萘-2,2-二酚的三氟甲磺酸酯 2-27用dppp作為配體插羰可得單羧酸酯2-28。而光學(xué)純二羧酸酯2-29在類似的條件也能得到,但必須要用4.4倍量的受阻胺(hindered amine),例如ethyldiisopropylamine;這種胺的用量對于二羰基化反應(yīng)來說是至關(guān)重要的

12、,多于或少于4.4倍量都會(huì)得到單酯2-28。由醛或酮派生的三氟甲磺酸烯醇酯通過插羰反應(yīng)可以得到,-不飽和酯。甾族酯可以從他們相應(yīng)的三氟甲磺酸芳香酯和烯醇酯制得。在下列化合物2-30中,三氟甲磺酸烯醇酯要比三氟甲磺酸芳香酯反應(yīng)活性更高,因此這個(gè)插羰反應(yīng)是逐步進(jìn)行的。首先,三氟甲磺酸烯醇酯插羰得到胺2-31;然后,在DMSO中用dppp作配體進(jìn)行第二次插羰得到酯2-32。通過插羰反應(yīng)制備羧酸是在水中進(jìn)行的。對于enol triflate和aryl triflate的羰基化反應(yīng)來說,選擇反應(yīng)溶劑是至關(guān)重要的。Enol triflate 2-33的插羰反應(yīng)制備羧酸要在水和DMF的混合溶劑中才得以進(jìn)行。

13、Aryl triflate 2-34的羰基化反應(yīng)要在水和DMSO的混合溶劑中進(jìn)行,并要用dppp作配體。由enol triflate 2-35制備,-不飽和羧酸2-36是用dppf作配體在水和DMF的混合溶劑中進(jìn)行的。非常有意思的是,在堿性條件下,碘苯可以和氯仿反應(yīng)生成苯甲酸,此反應(yīng)無需CO參與。其他的類鹵化物也可以用于插羰反應(yīng)。Phenyl fluorosulfonate 2-37插羰可得苯甲酸酯。Aryl(alkenyl)iodonium salts、aryl(alkenyl)iodonium salts 2-38和aryl(alkynyl)iodonium salts 2-39時(shí)活性非常

14、高化合物,他們在比較溫和的條件(室溫, 1 atm)下就可以插羰生成芳基、烯基和炔基酯。Iodoxybenzene 2-40在1atm,40oC的水溶劑中就可以發(fā)生插羰反應(yīng)得到苯甲酸。另外,苯甲酸的衍生物也可以通過芳基重氮鹽在溫和條件下插羰反應(yīng)制備。例如,苯基重氮鹽2-41在醋酸中插羰可得混合酸酐2-41。利用這個(gè)方法,硝基苯可以間接轉(zhuǎn)化成苯甲酸。在CsF存在下,芳基鹵化物能夠極其溫和的條件下進(jìn)行插羰反應(yīng),并以較高收率得到?;?-43。與酰氯不同,酰氟對于鈀催化劑來說是惰性的。苯磺酰氯2-44在160oC和titanium tetralkoxide存在下,經(jīng)過脫磺酸基和插羰反應(yīng)可以得到苯

15、甲酸酯2-45。雜芳環(huán)溴化物通過插羰反應(yīng)可以生成雜芳基酯(例如:2-46)和雜芳酰胺。甚至二氯吡嗪2-47和氯吡啶在比較苛刻的條件(120 oC, 40 atm)下都可以進(jìn)行插羰反應(yīng)。Trifluoroacetimidoyl iodides 2-48 在溫和條件下的插羰反應(yīng)可以被用來合成三氟甲基甘氨酸的衍生物2-49和2-50。在1 atm壓力,伯胺或仲胺存在的情況下,鹵化物的插羰反應(yīng)生成酰胺。帶有氨基的芳基溴化物的分子內(nèi)羰基化反應(yīng)可以得到內(nèi)酰胺,這個(gè)方法已經(jīng)被應(yīng)用于異喹啉生物堿2-51的合成。天然七元環(huán)內(nèi)酯2-52(tomaymycin, neothramycin)的合成也是通過這個(gè)方法。-

16、烯基-內(nèi)酯2-53的形成也是通過2-溴-3-烷氨基-1-丙烯的分子內(nèi)羰基化反應(yīng)。鄰二碘苯和伯胺的插羰反應(yīng)可以生成鄰苯二甲酰亞胺2-54。在DBU或2,6-二甲基吡啶存在下,碘苯和鄰苯二胺的插羰反應(yīng)得到2-苯基苯并咪唑2-56。手性的aryl或alkenyl oxazoline 2-59被制備是通過aryl或enol triflates在手性氨基醇2-57存在下先進(jìn)行插羰反應(yīng)得到酰胺2-58,然后再在SOCl2中脫水關(guān)環(huán)。對于插羰反應(yīng)來說,烯基氯化物一般是非常不活波的,但是氯乙烯是個(gè)例外,它可以和NH3在100oC發(fā)生插羰反應(yīng)生成邁克爾加成產(chǎn)物酰胺2-60,這個(gè)反應(yīng)的收率非常高。在一定條件下,鹵

17、化物還可以進(jìn)行兩次插羰反應(yīng),從而生成-酮酸的衍生物。它是單羰基化反應(yīng)的競爭反應(yīng)。用Ca(OH)2作堿,烷基膦作配體,碘苯在水中插羰生成-酮酸(苯基乙醛酸)2-61。同樣,在水和異丙醇的混合溶劑中,Ca(OH)2作堿,Me3P作配體,碘苯經(jīng)過兩次插羰和還原之后得到苦杏仁酸2-62。另外,碘苯和二級胺在用烷基膦或雙齒膦作配體的條件下經(jīng)過二次插羰反應(yīng)生成-酮酰胺2-63,此反應(yīng)的化學(xué)選擇性非常高。鄰碘苯胺衍生物的二次插羰產(chǎn)物可以轉(zhuǎn)化成靛紅2-65和喹啉2-64。氯苯在Cr(CO)3作用下,用PdCl2(MePh2P)2作催化劑經(jīng)過兩次插羰反應(yīng)生成-酮酰胺和苯甲酰胺。-酮酯2-67能夠通過碘苯和大位阻

18、二級胺的二次羰基化反應(yīng)形成,但是這個(gè)反應(yīng)的選擇性非常低。對于二次插羰反應(yīng)來說,烯基溴化物比芳基鹵化物的反應(yīng)活性更低。-酮酰胺能夠通過芳基和烯基溴化物的二次羰基化反應(yīng)得到,而-酮酯是不能夠通過他們在相應(yīng)醇中的羰基化反應(yīng)得到。3. 插羰反應(yīng)制備羧酸實(shí)驗(yàn)操作A 200-mL glass pressure bottle equipped with two valves and a pressure gauge was charged with 8 mg of Pd(PPh3)(Cl)2, 40 mg of triphenylphosphme, and 2.0 g of 2-(acetylamino)-

19、5-(1-methylethyl) phenylbromide. The bottle was then evacuated, refilled with argon three times, and charged further with 2.2 mL of deoxygenated tri-n-butylamine and 0.5 mL of deoxygenated water. The apparatus was then pressurized with 3 atm of carbon monoxide, sealed, heated 18 h with stirring at a

20、 bath temperature of 120-125 °C, and then allowed to cool. The final pressure was 1.1 atm at 23 °C. Hydrochloric acid (2.4 M) was added to the viscous orange-brown reaction mixture in four 2-mL portions with constant agitation. The crude yield of 2-11 which separated (95% pure by NMR) was

21、1.63 g (94%). Recrystallization from ethanol-water gave 1.35 g (78%) of a light yellow solid.4. 插羰反應(yīng)制備羧酸酯實(shí)驗(yàn)操作A mixture of the iodobenzene 2-1 (0.46 mmol), w-indo alcohol 2-2 (0.83 mmol), K2CO3 (1.38 mmol), and PdCl2 (0.04 mmol) in dry benzene (6 mL) was heated at 120 with stirring in an autoclave un

22、der carbon monoxide (12 atm) for 16 h. The reaction mixture was filtered and the easter 3 was isolated by column chromatography in 70% yield.(2R,4S)-4-3,5-Bis(trifluoromethyl)benzyl-(5-bromopyrimidin-2-yl)-amino-2-ethyl-6-methoxy-3,4-dihyfro-2H-1,5naphthridine-1-carboxylic acid ethyl ester (18 g) is

23、 dissolved in N,N-dimethylformamide (60 mL), and thereto are added palladium acetate (611 mg), 1,1-bis(diphenylphosphino)-ferrocene (3.02 g), ethane (31.7 mL) and triethylamine (37.9 mL). The mixture is purged by carbon monoxide at room temperature for 10 minutes, then is heated at 90 oC and stirred

24、 overnight under 40 psi of carbon monoxide. The reaction solution is cooled to room temperature, and thereto is added saturated brine and extracted with ethyl acetate. The organic layer is washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The resulti

25、ng residue is purified by column chromatography (silica gel; hexane:ethyl acetate = 8:1) to give (2R.4S)-4-3,5-bis(triflouromethyl)benzyl-(5-ethoxycarbonylpyrimidin-2-yl)amino-2-ethyl-6-methoxy-3,4-dihydro-2H-1,5naphthyridine-1-carboxylic acid ethyl ester (12.4 g).To a stirred solution of 3-(aminoca

26、rbonyl)-4-3-(methyloxay)penylamino-6-iodoquinoline (1 g) in ethanol (50 mL) was added triethylamine (0.63 mL) and dichlorobis(triphenylphosphine)palladium (II) (0.08 g). The flask was evacuated and refilled with nitrogen three times and then evacuated and refilled with carbon monoxide two times. The

27、 mixture was heated at 80oC under an atmosphere of carbon monoxide for 16 h. the mixture was cooled to 20oC and the solvent removed in vacuo. Purification by column chromatography on silica gel, eluting with 9:1 ethyl acetate: cyclohexane, gave the title compound as a pale yellow solid (0.8 g).6-bro

28、mo-4-2-(6-methyl-pyridin-2-yl)-5,6-dihydro-4H-pyrrolo1,2-Bpyrazol-3-yl-quinoline (22.7 g, 45 mmol) is added to a mixture of sodium acetate (19 g, 230 mmol) and the palladium catalyst 1,1-bis (diphenylphosphimo) ferrocene dichloropalladium (II) complex with dichloromethane (1:1) (850 mg, 1.04 mmol) i

29、n 130 mL methanol. Place the mixture under 50 psi carbon monoxide atmosphere and stir while warming to 90oC over 1 hour and with constant charging with additional carbon monoxide. Allow the mixture to cool over 8 hours, recharge again with carbon monoxide and heat to 90oC. The pressure may rise to a

30、bout 75 psi. The reaction is complete in about an hour when the pressure is stable and TLC (1:1 toluene/acetaone) shows no remaining bromide. Partition the mixture between methylene chloride (600 mL) and water (1 L). Extract the aqueous portion with an additional portion of methylene chloride (400 m

31、L). Filter the organic solution through a 300 mL silica plug and wash with 500 mL methylene chloride, 1200 mL ethyl acetate and 1500 mL acetone. Discard the acetone portion. Combine appropriate fractions and concentrate to yield 18.8 g (87.4%) of the desired subtitled intermediate as a pink powder.A

32、 solution of N-(4-chlorobenzyl)-4-hydroxy-6-iodo-3-quinolinecarboxamide (30.0 g), Et3N (19.1 mL), MeOH (110.6 mL), Pd(OAc)2 (431 mg), and 1,3-bis(diphenylphosphino)propane (791.9 mg) in 375 mL anhydrous DMF is stirred at room temperature until everything dissolves. CO (g) is slowly bubbled through f

33、or 2 days and the reaction is maintained at 70oC. The reaction is cooled to room temperature. The product is precipitated by adding 160 mL 1 N HCl into the reaction mixture. An orange solid precipitates is collected. The solid is triturated with EtOAc, filtered, and washed with CH2Cl2 to afford 23.8

34、 g (93 % yield) of the title compound as an off-white solid.A mixture of 2-(3-iodo-2-methyl-phenyl)-pyrrolidine-1-carboxylic acid tert-butyl ester (26 g, 0.067 mol), Pd(PPh3)4 (2.4 g, 0.002 mol), Et3N (14.3 mL, 0.1 mol), 110 mL of acetonitrile and 50 mL of methanol was stirred under 50 Psi of carbon

35、 monoxide at 50 °C for 8 h. The reaction mixture was filtered and concentrated in vacuo. The residue was dissolved in 250 mL of ethyl acetate, then washed with water and brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give crude product, which was purified by column chro

36、matography (petroleum ether: ethyl acetate 30:1 to 10:1) to afford the title product (20 g, 93%) as a gray solid.PdCl2 (18.4 g, 0.104 mol) and BINAP (27.6 g, 0.044 mol) were added to a solution of 5-(2-bromo-phenyl)-oxazole (331.0 g, 0.44 mol) and Et3N (242.2 g, 2.22 mol) in 6 L CH3OH/CH3CN (2:1) in

37、 steel bomb. The mixture was stirred at 100 °C under CO (1 atm) for 48 h. The mixture was filtered and the filtrate was evaporated. The residue was purified by column chromatography (EtOAc/petroleum = 1:10) to give 2-oxazol-5-yl-benzoic acid methyl ester (210.0 g, 70 %) as brown oil.5. 插羰反應(yīng)制備酰胺

38、實(shí)驗(yàn)操作A mixture of 2-52-A (6.3 mg, 11 rmnol), Pd(PPh3)4 (1.27 g, 1.1 mmol) and n-Bu3N (4.47 g, 24.2 mmol) in toluene (20 mL) was heated under carbon monoxide(10 atm) at 1l0oC for 24 h. Ethyl acetate was added to the reaction mixture and the organic layer was washed with 5% HCl, 5% Na2S2O3, sat. NaHCO3

39、 and then brine, dried over Na2SO4 and evaporated. The residue was purified by column chromatography ethy1 acetate-CH2Cl2 (1:l). The second fraction was 2-52 (3.93 g, 69 %).6. 插羰反應(yīng)制備醛醛可以通過鹵化物在不同氫源中的鈀催化的插羰反應(yīng)制備。芳基和烯基碘化物和溴化物在惰性溶劑中,三級胺存在的條件下與CO和H2(1:1)發(fā)生插羰反應(yīng)生成醛。而芳基氯化物要先生成碳酸鉻的衍生物后,才能在130oC的溫度下轉(zhuǎn)化成醛。甲酸鈉可以代

40、替H2被用作氫源來合成醛。氯苯在150oC的溫度下,用dippp作為配體,與CO和甲酸鈉反應(yīng)制得苯甲醛。用錫的氫化物作為氫源,Pd(Ph3P)4作為催化劑,芳基、烯基鹵化物或三氟甲磺酸酯和芐基、烯丙基氯化物的羰基反應(yīng)也能制備醛。硅的氫化物也能被用作氫源。重氮鹽6-1通過用Et3SiH或PHMS作為氫源,可以高收率快速的轉(zhuǎn)化成鄰甲基苯甲醛。7. 插羰反應(yīng)制備醛實(shí)驗(yàn)操作To the 45 mL-Parr bombwere added 3.95 g (25.0 mmol) of 3-bromopyridine, 10 mL of triethylamine, 10 mL of benzene, an

41、d 0.30 g (0.375 mmol) of dibromobis(triphenylphosphine)palladium (II). The bomb was then flushed with argon, sealed, and pressurized to 600 Psi with carbon monoxide. After the pressure was released, the bomb was re-pressurized to 600 Psi with carbon monoxide and finally pressurized to 1200 Psi with

42、hydrogen. The reaction vessel was heated in an oil bath with stirring at 145oC. After 20 min, the pressure reached a maximum of 1350 Psi. Times and pressure were periodically recorded until gas absorption stopped (26 hr), and the pressure in the reaction vessel had decreased to 1025 Psi. The reactio

43、n vessel was cooled, and the gases were slowly released. After addition of anhydrous ether, the reaction mixture was filtered to remove the triethylamine hydrochloride, concentrated in vacuo to remove ether, benzene, and triethylamine, and finally distilled to give 2.15 g of (80% yield) of product.T

44、he 75-mLreaction bomb was charged with 5.9 g (25.0 mmol) of 1,4-dibromobenzene, 11.2 g (60.0 mmol) of tri-n-butylamine, 15 mLof benzene, and 0.4 g (0.5 mmol) of dibromobis(triphenylphosphine)palladium (II). The bomb was then flushed with argon, sealed, and pressurized to 600 Psi with carbon monoxide

45、. After the pressure was released, the bomb was re-pressurized to 600 Psi with carbon monoxide and finally pressurized to 1200 Psi with hydrogen. After 15 min, the pressure reached 1375 Psi at 140oC and decreased to 600 Psi after 24 hr of treaction. The vessel was then cooled to room temperature and

46、 the pressure released. After addition of anhydrous ether, the reaction mixture was filtered to remove the triethylamine hydrochloride, concentrated in vacuo to remove ether, benzene, and triethylamine. After evaporation of the ether, the resulting solids were sublimed (100oC, 8 mm) to give 3.79 g o

47、f a mixture of the terephthalaldehyde and 1,4-dibromobenzene. The mixture was separated by chromatography on silica gel. There were obtained 0.66 g (2.8 mmol) of 1,4-dibromobenzene and 2.47 g (18.4 mmol) of 1,4-benzenedicarboxaldehyde (83% yield). Recrystallization from hexane yielded 2.21 g of pure

48、 dialdehyde.8. 插羰反應(yīng)制備酮在Zn, B, Al, Sn, Si, Hg等有機(jī)金屬化合物或其他親核試劑(他們可以進(jìn)攻?;Z中間體,發(fā)生金屬轉(zhuǎn)移和還原消去反應(yīng))的存在下,鹵化物和類鹵化物的羰基化反應(yīng)可以生成酮。芳基碘化物在烷基碘化物和Zn-Cu存在條件下發(fā)生插羰反應(yīng),以非常高的收率生成了烷基芳基酮。這個(gè)反應(yīng)首先生成烷基鋅試劑,然后再發(fā)生金屬轉(zhuǎn)移和還原消去反應(yīng)。在堿性條件下,有機(jī)硼化物可以被用于合成酮的插羰反應(yīng)中:有機(jī)鋁化物(例如三苯基鋁)可以被用于合成酮的插羰反應(yīng)。應(yīng)注意的是,i-Bu3Al應(yīng)用此類反應(yīng)時(shí),往往會(huì)發(fā)生還原羰基化反應(yīng),從而生成相應(yīng)的醇:有機(jī)錫化物,如芳基、烯基和炔基

49、錫化物,可以用于合成酮的插羰反應(yīng)。反應(yīng)機(jī)理和實(shí)例應(yīng)用如下圖所示:有機(jī)硅化物可以用于合成酮的插羰反應(yīng):烷基和芳基汞(II)的鹵化物也可以用于酮的合成反應(yīng),因?yàn)榇祟惙磻?yīng)并不多見,所以在此就不再列舉。如果用活性亞甲基化合物(例如-酮酯或丙二酸酯)代替醇類化合物進(jìn)行插羰反應(yīng),可以得到-酮酯或丙二酸酯的衍生物8-1。對于這個(gè)反應(yīng)來說,dppf是非常好的配體。通過烯醇式陰離子捕獲酰基鈀中間體的方式發(fā)生分子內(nèi)反應(yīng),可以形成五元和六元環(huán)?;衔?-2的形成就是一個(gè)典型實(shí)例。這是一個(gè)非常有價(jià)值的反應(yīng)。當(dāng)有一個(gè)可烯醇化的羰基存在的時(shí)候,C和O之間的捕獲競爭就會(huì)發(fā)生。一般來講,在形成同樣大小環(huán)的情況下,O的捕獲能力

50、要強(qiáng)于C的捕獲能力,因此更多的情況下是形成內(nèi)酯。如果在適當(dāng)?shù)奈恢糜须p鍵存在,那么在CO插入完成之后會(huì)緊接著發(fā)生烯鍵插入反應(yīng)。在化合物8-3的分子內(nèi)反應(yīng)中,通過使用不同的催化劑可以得到不同的產(chǎn)物:使用Pd(dba)2作催化劑,插羰后得到產(chǎn)物8-4;而使用PdCl2(Ph3)2作催化劑則得到化合物8-5。下面是通過芳基鹵化物與分子內(nèi)雙鍵的羰基化反應(yīng)合成雜環(huán)化合物8-6的實(shí)例:鄰碘苯酚與降冰片二烯和CO反應(yīng)得到內(nèi)酯8-7,它可以通過反Diels-Alder反應(yīng)進(jìn)一步轉(zhuǎn)化成香豆素8-8。有末端炔烴和非末端炔烴參與的鹵化物羰基化反應(yīng)可以得到各種各樣的產(chǎn)物。取代二氫茚酮8-9的合成就是通過在Pd(Ph3P

51、)4和Zn催化下鄰二碘苯和炔烴、CO反應(yīng)制得的。在末端炔烴存在情況下,芳基碘化物的羰基化反應(yīng)可以制備?;矡N8-10。在這個(gè)反應(yīng)中,使用雙齒配體(如dppf)可以得到非常好的結(jié)果。但如果使用Ph3P作為配體,苯乙炔主要轉(zhuǎn)化成二苯乙炔。通過類似的反應(yīng),三氟甲磺酸酯8-11可以生成炔酮8-12:用Zn-Cu試劑作為還原劑,通過Pd和Cp2TiCl2協(xié)同催化下,烯酮8-13能夠以較高收率被制備:通過鹵化物與炔烴的羰基化應(yīng)制得的炔基酮可以和自身具有的親和試劑進(jìn)一步發(fā)生分子內(nèi)反應(yīng):碘苯和芐基乙炔8-14通過羰基化反應(yīng)得到(E)-3-arylidenebutenolide 8-16(也可以通過苯乙?;驳聂驶磻?yīng)制備)。烯基鈀化物8-15被形成通過Pd-H加成反應(yīng)。接著烯醇形成,雙鍵異構(gòu)化,二次羰基化反應(yīng)得到丁烯羥酸內(nèi)酯8-16。在10 atm下,CO和CO2混合氣體中,碘苯和取代炔丙基醇8-17反應(yīng)得到3(2H)-furanone 8-20。首先碘苯和醇8-17以及CO通過羰基化反應(yīng)生成苯乙酰炔基醇8-18;然后CO2與醇8-18加成得到碳酸酯8-19;

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