【DOC】-FeCl3催化羰基化合物與芳烴的還原Friedel-Crafts 烷基化反應(yīng)-圖文

FeCl3催化羰基化合物與芳烴的還原Friedel-Crafts烷基化反應(yīng)_圖文

2009年第29卷

第3期,403～408

e

有機(jī)化學(xué)

ChineseJournalofOrganicChemistry

Vol.29,2009No.3,403～408

*E-mail:gqlai@

ReceivedApril23,2008;revisedSeptember11,2008;acceptedNovember3,2008.

浙江省自然科學(xué)基金(No.Y4080380)和浙江省錢江人才計劃基金(No.2008R10018)資助項目.

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有機(jī)化學(xué)Vol.29,2009

1實(shí)驗(yàn)

1.1試劑

所用FeCl3,AlCl3,ZnCl2,TiCl4,InCl3,CuCl2,有機(jī)溶劑,羰基化合物和芳香烴及雜環(huán)化合物均為市售化學(xué)純藥品;氯硅烷為市售分析純藥品.溶劑和氯硅烷在使用前需經(jīng)過干燥或蒸餾.1.2儀器

GC-MS采用TraceDSQGC-MSColumn測定;核磁共振譜采用BrukerAdvance400MHz型核磁共振儀測定,CDCl3為溶劑,TMS為內(nèi)標(biāo);紅外光譜采用液膜或壓片法,在BrukerTensor-27型紅外儀上測定.1.3羰基化合物的還原烷基化反應(yīng)

在25mL三口燒瓶中加入路易斯酸催化劑(0.025mmol),5mL有機(jī)溶劑,羰基化合物1(0.5mmol),噻酚或者芳烴2(0.55mmol)和二甲基氯硅烷(0.5mmol),在氮?dú)獗Ｗo(hù)下加熱回流數(shù)小時.實(shí)驗(yàn)過程中通過薄層硅膠板(TLC)跟蹤,用紫外燈檢測.反應(yīng)完全后,加入稀鹽酸終止反應(yīng).乙醚萃取,有機(jī)層用飽和碳酸氫鈉和氯化鈉溶液各洗兩次,然后用無水硫酸鎂干燥,減壓蒸去有機(jī)溶劑,經(jīng)柱層析得烷基化產(chǎn)物3

.

Scheme1

2.3產(chǎn)物數(shù)據(jù)

2-(1-苯基乙基)噻吩(3a)[15a]:1HNMR(400MHz,CDCl3)δ:7.30～7.17(m,5H,ArH),7.11(d,J＝8.0Hz,1H,thiophene-H),6.94～6.87(m,1H,thiophene-H),6.78(d,J＝8.0Hz,1H,thiophene-H),4.32(q,J＝4.6Hz,1H,CH),1.69(d,J＝4.8Hz,3H,CH3);13CNMR(100MHz,CDCl3)δ:150.84,146.41,128.64,128.40,127.69,126.89,126.67,125.52,123.77,123.11,41.05,23.32;IR(film)νmax:3026.5,2968.6,1610.2,1492.9,1451.5,1383.5,1262.8,1223.6,1047.9,1027.3,850.6,828.9,760.0,698.1cm－

1;MSm/z(%):188(M＋

,45),173(100),129(10).

2-[1-(4-氯)苯基乙基]噻吩(3b):1HNMR(400MHz,CDCl3)δ:7.32～7.16(m,5H,Ar-Handthiophene-H),6.97(t,J＝8.0Hz,1H,thiophene-H),6.83(d,J＝8.0Hz,1H,thiophene-H),4.36(q,J＝4.2Hz,1H,CH),1.72(d,

J＝3.0Hz,CH3CH);13CNMR(100MHz,CDCl3)δ:150.01,144.45,132.28,128.70,127.70,126.63,125.70,124.14,123.15,120.08,40.28,23.17;IR(film)νmax:3080.3,3040.2,3026.0,2965.2,2891.3,2843.5,1594.5,1492.3,1451.6,1390.4,1372.5,1060.2,1092.0,1014.1,950.6,827.7,804.5,761.6,745.2,698.7cm－

1;MSm/z

(%):223(M＋

,19),222(52),209(36),207(100),172(25),171(30).

2-[1-(4-甲氧基)苯基乙基]噻吩(3c):1HNMR(400MHz,CDCl3)δ:7.27～7.14(m,3H,ArH),6.92(d,J＝8.0Hz,1H,ArH),6.88～6.84(m,2H,thiophene-H),6.80(d,J＝8.0Hz,1H,thiophene-H),4.31(q,J＝4.2Hz,1H,CH),3.80(s,3H,CH3OAr),1.69(d,J＝4.6Hz,3H,CH3CH);

13

CNMR(100MHz,CDCl3)δ:158.15,151.34,138.29,

128.24,126.53,123.44,122.74,119.70,113.84,55.27,39.98,23.35;IR(film)νmax:2965.8,2910.3,2812.5,1610.6,1582.3,1462.1,1403.7,1302.5,1266.7,1246.2,1178.4,1035.1,862.6,631.0,810.8,697.9,581.3cm－

1;

MSm/z(%):218(M＋

,40),203(100),160(9).

2-[1-(4-硝基)苯基乙基]噻吩(3d)[15a]:1HNMR(400MHz,CDCl3)δ:8.48～7.89(m,4H,ArH),7.75～7.36(m,2H,thiophene-H),7.25(d,J＝8.2Hz,1H,thiophene-H),4.25(q,J＝4.2Hz,1H,CH),1.71(d,J＝5.6Hz,3H,CH3CH);MSm/z(%):233(M＋

,51),218(100),172(28).

2-(1-苯基正丁基)噻吩(3e):1HNMR(400MHz,CDCl3)δ:7.30～7.24(m,3H,ArH),7.20～7.15(m,2H,ArH),7.11(d,J＝8.6Hz,1H,thiophene-H),6.89(t,J＝

8.2Hz,1H,thiophene-H),6.80(d,J＝8.0Hz,1H,thio-phene-H),4.12(dd,J＝4.2,4.2Hz,1H,CHC3H8),2.04(m,2H,CH2C2H5),1.29(m,2H,CH2CH3),0.91(t,J＝5.2Hz,3H,CH3);13CNMR(100MHz,CDCl3)δ:149.93,146.43,144.92,128.51,127.84,126.38,125.32,123.55,119.98,46.72,39.69,21.13,14.05;IR(film)νmax:3062.6,3026.6,2957.0,2929.4,2870.7,1598.2,1493.5,1452.6,1350.8,1259.6,1221.3,1067.4,1031.3,851.2,806.0,775.6,749.3,679.3cm－

1;MSm/z(%):216(M＋

,16),173

(100),129(8).

2-(1,1-二苯基甲基)噻吩(3f)[15b]:1HNMR(400MHz,CDCl3)δ:7.30～7.18(m,11H,ArHandthiophene-H),6.92(dd,J＝8.2,8.2Hz,1H,thiophene-H),6.68(d,J＝8.6Hz,1H,thiophene-H),5.67(s,1H,CH);13CNMR(100MHz,CDCl3)δ:143.88,129.07,129.01,128.92,128.83,128.75,128.60,128.54,128.45,126.79,126.65,126.52,126.15,125.57,124.61,122.85,52.45;IR(KBr)νmax:3060.5,3022.6,1597.4,1493.6,1448.4,1075.6,1029.4,

No.3

李志芳等：FeCl3催化羰基化合物與芳烴的還原Friedel-Crafts烷基化反應(yīng)

405

750.6,737.3,698.5cm－

1;MSm/z(%):250(M＋

,100),217(20),173(68),165(30).

2-芐基噻吩(3g)[15c]:1HNMR(400MHz,CDCl3)δ:7.35～7.18(m,5H,Ar-H),7.12(d,J＝8.2Hz,1H,thio-phene-H),6.93～6.89(m,1H,thiophene-H),6.80(d,J＝8.0Hz,1H,thiophene-H),3.97(s,2H);MSm/z(%):174(M＋

,100),129(11),96(42).

2-(4-氯代芐)噻吩(3h)[15d]:1HNMR(400MHz,CDCl3)δ:7.29～7.09(m,4H,ArH),7.03(d,J＝8.0Hz,1H,thiophene-H),6.95～6.91(m,1H,thiophene-H),6.82(d,J＝8.0Hz,1H,thiophene-H),4.15(s,2H);MSm/z(%):210(29),208(M＋

,88),173(100),171(25.29),129(18),97(36),85(27).

(E)-1-苯基-3-(2-噻吩)-1-丙烯(3i)[15e]:1HNMR(400MHz,CDCl3)δ:7.48～7.29(m,5H,ArH),7.25(d,J＝8.0Hz,1H,thiophene-H),7.08～7.01(m,1H,thiophene-H),6.96(d,J＝8.2Hz,1H,thiophene-H),6.60(d,J＝8Hz,1H,CH(Ar)＝CH),6.50～6.43(m,1H,CH(CH2)＝CH),3.82(d,J＝4.6Hz,2H,CH2);MSm/z(%):200(M＋

,100),184(21),167(25),114(32),96(20).

2-環(huán)己基噻吩(3j)[15e]:1HNMR(400MHz,CDCl3)δ:7.10(d,J＝8Hz,1H,thiophene-H),6.92～6.90(m,1H,thiophene-H),6.81(d,J＝8Hz,1H,thiophene-H),3.10～3.02(m,1H,CH),2.13～2.09(m,2H),1.81～1.75(m,2H),1.69～1.64(m,2H),1.62～1.58(m,2H);MSm/z(%):152(M＋

,31),86(100),68(89),56(65).

1,1-二苯基乙烷(3k)

[15c]:1

HNMR(400MHz,CDCl3)

δ:7.29～7.12(m,10H,ArH),4.14(dd,J＝8.0,8.0Hz,1H,CH),1.63(d,J＝4.0Hz,3H,CH3);MSm/z(%):182(M＋

,37),167(100),65(21),152(19).

1-對甲苯基苯乙烷(3l)[15a]:1HNMR(400MHz,CDCl3)δ:7.21～7.02(m,9H,ArH),4.08(dd,J＝8.0,8.0Hz,1H,CH),2.27(s,3H,CH3Ar),1.58(d,J＝4.6Hz,3H,CH3CH);13CNMR(100MHz,CDCl3)δ:146.57,143.39,135.39,130.39,129.03,128.41,127.64,126.07,125.80,44.36,21.92,20.94;MSm/z(%):196(M＋

,36),184(100),166(35),114(9),89(15).

1-(2,5-二甲基苯基)-1-苯基乙烷(3m)[15a]:1HNMR(400MHz,CDCl3)δ:7.38～7.07(m,9H,ArH),4.40(dd,J＝8.0Hz,8.0Hz,1H,CH),2.42(s,3H,CH3Ar),2.31(s,3H,CH3Ar),1.74(d,J＝5.6Hz,3H,CH3CH);MSm/z(%):210(M＋

,46),195(100),180(29),165(28).

4-(1-苯基乙基)苯酚(3n)[15a]:1HNMR(400MHz,CDCl3)δ:7.38～7.02(m,9H,ArH),4.62(s,1H,OH),4.34(q,J＝5.6Hz,1H,CH),1.60(d,J＝5.6Hz,3H,

CH3);MSm/z(%):198(M＋

,47),183(100),165(25),153(12).

2-甲基-5-(1-苯基乙基)噻吩(3p)[15a]:1HNMR(400MHz,CDCl3)δ:7.34～7.13(m,5H,ArH),7.08(d,J＝8.6Hz,1H,thiophene-H),6.79(d,J＝8.0Hz,1H,thiophene-H),4.21(q,J＝5.6Hz,1H,CH),2.39(s,3H,CH3-thio-phene),1.61(d,J＝4.6Hz,3H,CH3CH);MSm/z(%):202(M＋

,15),200(46),200(31),187(100),185(39).

3-甲基-2-(1-苯基乙基)噻吩(3q)[15c]:1HNMR(400MHz,CDCl3)δ:7.26～7.15(m,5H,ArH),7.11～7.06(m,1H,thiophene-H),6.57～6.53(m,1H,thiophene-H),4.34(q,J＝5.2Hz,1H,CH),2.06(s,3H,CH3-thiophene),1.62(d,J＝5.2Hz,3H,CH3CH);MSm/z(%):202(M＋

,17),200(36),187(100),185(41).

2-氯-5-(1-苯基乙基)噻吩(3r):1HNMR(400MHz,CDCl3)δ:7.25～7.15(m,3H,ArH),7.08(d,J＝8.0Hz,2H,ArH),6.63(d,J＝7.8Hz,1H,thiophene-H),6.46(d,J＝8.0Hz,1H,thiophene-H),4.11(q,J＝4.6Hz,1H,CH),1.53(d,J＝5.6Hz,3H,CH3CH);13CNMR(100MHz,CDCl3)δ:148.80,143.68,132.54,128.77,128.57,128.41,128.05,125.59,123.03,40.49,22.77;IR(film)νmax:2951.3,2920.2,2854.6,1491.3,1446.3,1416.5,1094.0,1022.7,1014.1,976.2,829.0,786.2cm－

1;MSm/z

(%):222(M＋

,22),207(100).

2結(jié)果和討論

2.1苯乙酮的還原烷基化反應(yīng)

以苯乙酮和噻吩為底物,二甲基氯硅烷為質(zhì)子源,選用不同的催化劑和溶劑研究苯乙酮和噻酚的還原烷基化反應(yīng),優(yōu)化反應(yīng)條件(表1).

首先考察不同的路易斯酸催化苯乙酮的還原烷基化反應(yīng),從表1可以看出FeCl3的催化效果最佳(Entry1),以良好的收率得到目標(biāo)產(chǎn)物2-(1-苯基乙基)噻吩,區(qū)域選擇性也較為理想(o∶m＝89∶11).在InCl3催化下,得到2-(1-苯基乙基)噻吩和2,5-二(1-苯基乙基)噻吩的混合物,二者的比例是2∶1(Entry2).其它路易斯酸,如:ZnCl2和AlCl3雖然也能得到預(yù)期的產(chǎn)物,但收率較低(Entries3和4).而TiCl4和CuCl2對該反應(yīng)沒有催化效果(Entries5和6).

我們還考察了不同溶劑對該反應(yīng)的影響.在THF,CH3CN,CHCl3和CH2Cl2溶劑中,以較低的收率得到烷基化產(chǎn)物2-(1-苯基乙基)噻吩(Entries8,9,10和11).而在DME,DMF和DMSO溶劑中,沒有檢測到目標(biāo)產(chǎn)物(Entries12,13和14).同時,溫度對該反應(yīng)的影響也比

406

有機(jī)化學(xué)Vol.29,2009

表1二甲基氯硅烷作用下FeCl3催化苯乙酮和噻酚的還原Friedel-Crafts烷基化反應(yīng)

Table1FeCl3catalyzedreductiveFriedel-Craftsalkylationofthiophenewithacetophenoneinthepresenceofchlorodimethyl-

silane

較大,在室溫下,把反應(yīng)時間延長至24h,產(chǎn)率只有8%(Entry7).因此,羰基化合物的還原烷基化的最佳反應(yīng)條件為:FeCl3為催化劑,以正己烷為溶劑,在回流狀態(tài)下進(jìn)行反應(yīng).

2.2FeCl3催化羰基化合物和噻酚的還原烷基化反應(yīng)

在上述優(yōu)化的反應(yīng)條件下考察了該試驗(yàn)方法的使用范圍,從表2可以發(fā)現(xiàn),芳香族酮和醛都可以與噻吩進(jìn)行還原烷基化反應(yīng),以良好的收率得到相應(yīng)的烷基化噻吩衍生物.在該反應(yīng)條件下醚鍵、硝基和C＝C雙鍵不受影響.但是,當(dāng)二苯甲酮作為反應(yīng)底物時,由于位阻效應(yīng),在相同的反應(yīng)條件下反應(yīng)8h,產(chǎn)率只有15%(Entry6).在不使用其它任何有機(jī)溶劑,而以過量的噻吩作為溶劑,則以93%的收率得到烷基化產(chǎn)物2-(1,1-二苯基甲基)噻吩,區(qū)域選擇性為99∶1(Entry7).在FeCl3催化下,環(huán)己酮也能與噻吩進(jìn)行反應(yīng),以77%的收率和99%的區(qū)域選擇性得到2-環(huán)己基噻吩(Entry11).鏈狀脂肪族醛和酮在該體系下不能進(jìn)行還原烷基化反應(yīng),只得到羰基化合物的還原氯代物和醚[14].

在FeCl3催化下,芳烴,2-甲基噻酚,3-甲基噻酚和2-氯噻酚也能與苯乙酮進(jìn)行還原烷基化反應(yīng),以良好的收率得到相應(yīng)的烷基化產(chǎn)物(表3).由于氯苯的反應(yīng)活性較差,僅以31%的收率得到烷基化產(chǎn)物(Entry5).2.3反應(yīng)機(jī)理探討

FeCl3催化的羰基化合物的還原烷基化反應(yīng)的可能

EntrySolventewisacidYield/%Regiosel.(o∶m)1234567d

n-HexaneFeCl393n-HexaneInCl320n-HexaneZnCl210n-HexaneAlCl310n-HexaneCuCl20n-HexaneTiCl40n-HexaneFeCl38

FeCl310

ca

b

89∶11

71∶2981∶19

8THF

9CH3CNFeCl33511CH2Cl2FeCl37512DME13DMF

ac

10CHCl3FeCl345e67∶33

FeCl30FeCl30FeCl30

Isolatedyieldsbasedon1used.bSelectivitiesweredeterminedbyGC-MS.Theratioof2,5-di(1-phenylethyl)thiopheneto2-(1-phenylethyl)thiophene

14DMSOwas2∶1.dr.t.,24h.e2,5-Di(1-phenylethyl)thiophenewasobtainedin15%isolatedyield.

表2FeCl3催化羰基化合物和噻酚的還原Friedel-Crafts烷基化反應(yīng)

Table2FeCl3

catalyzedreductiveFriedel-Craftsalkylationofthiophenewithcarbonylcompounds

EntryR11Ph

R2Time/hYielda/%MajorproductCH34

9389938487159393

3a3b3c3d3e3f3f

Regiosel.(o∶m)b

89∶1175∶2591∶965∶3583∶1799∶1

24-ClC6H4CH3434-MeOC6H4CH3444-NO2C6H4CH385Ph6Ph7Ph8Ph

c

n-C3H75Ph8Ph4H4

3g92∶83i80∶20

94-ClC6H4H4893h77∶2310C6H5CH＝CHH88012C5H11CH34

a

11(C2H4)54773j99∶1

0d

13C4H9H40

Isolatedyieldsbasedon1used.bSelectivitiesweredeterminedbyGC-MS.cFeCl3(5mol%),benzophenone(1mmol),thiophene(5mL),chlorodimethylsilane(1

d

mmol),reflux.Amixtureof2-chloroheptane(17%)andether(65%).eAmixtureof1-chloropentane(51%)anddipentylether(47%).

No.3

李志芳等：FeCl3催化羰基化合物與芳烴的還原Friedel-Crafts烷基化反應(yīng)表3FeCl3催化苯乙酮與芳烴的還原烷基化反應(yīng)

Table3FeCl3

catalyzedreductiveFriedel-Craftsalkylationofareneswithacetophenone

407

EntryArHTime/hYielda/%Majorproduct1Benzene2Toluene4Phenol5Chlorobenzene

493496495831

3k3l3m3n3o3p3q3r

o∶p＝28∶72

o∶p＝44∶56

o∶m＝95∶5o∶m＝72∶28o∶m＝99∶1Regiosel.b

31,4-Dimethylbenzene498

62-Methylthiophene49973-Methylthiophene49982-Chlorothiophene496

a

Isolatedyieldsbasedon1used.bSelectivitiesweredeterminedbyGC-MS.

機(jī)理為(Scheme2):(1)FeCl3催化下,羰基化合物被二甲基氯硅烷還原成相應(yīng)的硅醚A;(2)硅醚A生成碳正離子中間體B;(3)該中間體B與芳烴進(jìn)行親電取代反應(yīng)生成相應(yīng)的烷基化產(chǎn)物C.反應(yīng)過程中,如果碳正離子中間體穩(wěn)定性較弱會產(chǎn)生氯代物和醚.如:2-庚酮與噻吩的反應(yīng)(表2,Entry12),得到2-氯庚烷和二庚醚的混合物.說明脂肪族的酮所形成的碳正離子中間體B穩(wěn)定性比較差,反應(yīng)按Step2'或者Step3'進(jìn)行[11]

.

References

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Scheme2

3結(jié)論

在二甲基氯硅烷作用下,FeCl3能催化羰基化合物與芳香烴及噻酚的還原Friedel-Crafts烷基化反應(yīng),以良好的收率和區(qū)域選擇性得到相應(yīng)的烷基化產(chǎn)物.

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