含吡啶基或苯基N,O-二齒配體化合物的合成

張雙龍,華宇鵬,董清晨,郭志強,韓鴻章,魏學紅

含吡啶基或苯基N,O-二齒配體化合物的合成

張雙龍,華宇鵬,董清晨,郭志強,韓鴻章,魏學紅＊

(山西大學應用化學研究所,山西太原030006)

以2-甲基吡啶和N,N-二甲基鄰甲苯胺為起始原料,經正丁基鋰去氫后與不同的酮或苯甲醛加成,然后水解,進而合成一類含N,O-二齒配體化合物,該方法反應條件溫和,后處理簡便,產率高,并通過1H NMR和13C NMR對產物進行了分析和表征.

N,O-二齒配體化合物;合成;分析表征

含吡啶官能團的配體化合物(I-IV)近年來引起了人們很大的興趣[1-6],如圖1所示.這些配體能夠與金屬中心形成許多種成鍵模式.如:η3-氮雜烯丙基配位、單齒的氨基配位、雙齒N,N-橋聯或螯合配位等.這些金屬配合物具有不同尋常的立體構型和不同形式的鍵合模式.

圖1 幾種常見的含吡啶基配體Fig.1 Some common pyridyl ligands

吡啶類化合物是合成醫(yī)藥、農藥、香料、染料、飼料添加劑、橡膠加工助劑等產品的重要原料,應用非常廣泛,深加工前景相當廣闊.含吡啶基N,O-二齒配體由于同時具有氮原子和氧原子配位中心,其金屬有機化合物在烯烴聚合、丙交酯開環(huán)聚合及Kumada偶聯反應中表現出良好的催化活性[7-12],進而含N,O-二齒配體金屬配合物的研究引起了大家的廣泛關注.

隨著一些新型N,O-二齒配體的合成,有關這類配體的金屬有機化合物的合成也逐漸增多[13-15].在探究金屬和碳原子間的成鍵機理方面與催化反應機理方面有很大的作用.在此,我們選用2-甲基吡啶和N,N-二甲基鄰甲苯胺為起始原料,經鋰化后與不同的酮(或醛)加成,然后水解合成了含吡啶基和苯基類的N,O-二齒配體化合物.分別如圖2和圖3(P256)所示.

圖2 含吡啶基N,O-二齒配體的合成Fig.2 Synthesis of pyridyl N,O-bidentate ligands

圖3 含苯基N,O-二齒配體的合成Fig.3 Synthesis of benzyl N,O-bidentate ligands

1 實驗部分

1.1 試劑與儀器

2-甲基吡啶(Alfa Aesar試劑公司,分析純),N,N-二甲基鄰甲苯胺(Alfa Aesar試劑公司,分析純),環(huán)己酮(分析純,北京化學試劑公司),苯乙酮(分析純,北京化學試劑公司),丁酮(分析純,北京化學試劑公司),苯甲醛(分析純,北京化學試劑公司),正丁基鋰(Alfa Aesar試劑公司,正己烷溶液);N,N’-四甲基乙二胺(TMEDA)(Alfa Aesar試劑公司,分析純),實驗中所用溶劑經干燥、蒸餾后使用;1H NMR(300 MHz)和13C NMR(75 MHz)核磁數據由Bruker DRX-300超導核磁共振儀測定.

1.2 實驗步驟

1.2.1 [(2-C5H4N)CH2C(OH)(CH2)4CH2](1)

在冰浴冷卻下,將正丁基鋰(19.2 mL,56.4 mmol)滴加到攪拌中的2-甲基吡啶(5.257g,56.4 mmol)的30 mL四氫呋喃溶液中,撤去冰水浴,溫度自然升至室溫繼續(xù)反應2 h得到深紅色溶液;將反應液重新冷卻至0°C,將環(huán)己酮(5.85 mL,56.4 mmol)慢慢滴加到上述反應溶液中,溶液逐漸由深紅色變成淺黃色,恢復至室溫后再反應2 h,將上述反應液倒入一盛有冰水的燒杯中,攪拌至冰塊全部融化,使得水解完全后,用無水乙醚(3×20 mL)萃取,合并有機相,用無水硫酸鎂進行干燥,真空除去易揮發(fā)溶劑,減壓蒸餾得到淺黃色油狀物1(9.05 g,84%).1H NMR(300 MHz,298K,CDCl3):δ(ppm)1.28～1.66[m,10 H,(CH2)5],2.88 (s,2 H,CH2),5.69(b,1 H,OH),7.12(m,2 H,C5H4N),7.60(m,1 H,C5H4N),8.47(m,1 H,C5H4N);13C NMR(CDCl3):δ(ppm)8.53(CH2CH3),27.10(CH),34.10(CH2CH3),45.98(CH2),73.38(CCH3), 121.48,124.53,136.71,148.58,160.15(C5H4N).

1.2.2 [(2-C5H4N)CH2C(OH)(Ph)CH3](2)

用苯乙酮代替環(huán)己酮,實驗步驟同1.2.1,得橙黃色油狀物2,產率87%.1H NMR(300 MHz,298K, CDCl3):δ(ppm)1.80(s,3 H,CH3),3.46(d,3 H,CH2),7.05(b,1 H,OH),7.19(m,1 H,Ar-H),7.29 (m,1 H,Ar-H),7.39(m,1 H,Ar-H),7.50(m,2 H,Ar-H),7.74(m,3 H,C5H4N),8.64(m,1 H, C5H4N);13C NMR(CCl3D):δ(ppm)30.73(CH3),48.95(CH2),74.65(Ar-C),121.56,124.42,136.81, 148.15,159.32(C5H4N),126.17,127.91,128.61,133.16,(Ar).

1.2.3 [(2-C5H4N)CH2C(OH)(CH2CH3)CH3](3)

用丁酮代替環(huán)己酮,實驗步驟同1.2.1,得橙黃色油狀物3,產率85%.1H NMR(300 MHz,298K, CDCl3):δ(ppm)0.84(t,3 H,CH2CH3),1.46(q,2 H,CH2CH3),1.07(s,3 H,CH3),2.80(q,2 H,CH2), 5.76(b,1 H,OH),7.08(m,2 H,C5H4N),7.57(m,1 H,C5H4N),8.44(m,1 H,C5H4N);13C NMR(CDCl3):δ(ppm)8.53(CH2CH3),27.10(CH3),34.10(CH2CH3),45.98(CH2),73.38(CCH3),121.48, 124.53,136.71,148.58,160.15(C5H4N).

1.2.4 [1-(2-(C2H6N)C6H4)CH2C(OH)(CH2)4CH2](4)

將N,N-二甲基鄰甲苯胺(5.25 g,38.8 mmol)與N,N’-四甲基乙二胺(1∶1)的混合物加入到盛有30 mL無水乙醚的Schlenk瓶中,攪拌均勻,冷卻至0℃,將正丁基鋰(16.2 mL,2.87 mol/L)用注射器緩慢滴加到上述溶液中,升至室溫后繼續(xù)反應2 h變?yōu)榱咙S色溶液;重新將上述反應液冷卻至0℃,將環(huán)己酮(4 mL,46.6 mmol)慢慢滴加到上述反應液中,溶液逐漸由亮黃色變成淺黃色,恢復至室溫后繼續(xù)反應2 h,然后在0℃用氯化銨的飽和水溶液水解,用無水乙醚(3×20 mL)萃取,所得有機相用無水硫酸鎂干燥,將溶劑旋干,減壓蒸餾得淺黃色油狀產物4(7.06 g,78%)1H NMR(300 MHz,298K,CDCl3):δ(ppm)2.67(s,6H, NC2H6),1.29～1.62(m,10H,(CH2)5),2.90(s,2H,C6H4CH2),7.05～7.24(m,4H,C6H4).

1.2.5 [1-(2-(C2H6N)C6H4)CH2C(OH)(Ph)CH3](5)

合成方法與化合物4相同,化合物5為黃色油狀產物73%.1H NMR(300 MHz,298K,CDCl3):δ(ppm) 1.16(s,3H,CCH3),2.65(s,6H,NC2H6),3.10～3.13(q,2H,C6H4CH2),6.77～7.41(m,9H,C6H4; C6H5),7.83(s,1H,OH).

1.2.6 [1-(2-(C2H6N)C6H4)CH2CH(OH)(Ph)](6)

化合物6的合成方法與化合物4相同,白色晶狀固體,產率72%.1H NMR(300 MHz,298K,CDCl3):δ (ppm)2.74(s,6H,NC2H6),3.01～3.23(m,2H,C6H4CH2),4.9～4.93(d,1H,OH),6.98～7.36(m,9H, C6H4;C6H5).

1.2.7 [1-(2-(C2H6N)C6H4)CH2C(OH)(C2H4)CH3](7)

化合物7的合成方法與化合物4相似,淺黃色油狀液體,產率52%.1H NMR(300 MHz,298K,CDCl3): δ(ppm)0.92～1.02(m,5H,CC2H5),1.43～1.50(m,3H,CCH3),2.67(s,6H,NC2H6),2.58～3.06(m, 2H,C6H4CH2),7.05～7.22(m,9H,C6H4).

2 結果和討論

在合成1-3化合物中,酮必須在低溫慢慢滴加至吡啶甲基鋰溶液中,否則極易發(fā)生酮的羥醛縮合等副反應,影響產率,而且產品難以提純.在合成4-7化合物中,直接用正丁基鋰鋰化N,N-二甲基鄰甲苯胺,反應不夠完全,導致下一步加成反應副反應增多,產品難以分離純化,在實驗過程中,我們曾嘗試改變溶劑、反應溫度等措施,均不能獲得滿意的效果.通過加入等量的N,N’-四甲基乙二胺,增強正丁基鋰的堿性,使得N,N-二甲基鄰甲苯胺的去氫反應進行的較完全,最終產率也得到了很大的提高.

在合成1-7化合物的水解過程中,中性或弱堿性條件下,水解不夠完全,導致產率降低,在鹽酸等酸性條件下,易發(fā)生脫水反應,經過反復試驗發(fā)現,使用弱酸性的飽和氯化銨水溶液,并在冰水浴條件下結果最佳.造成不同的酮或醛生成的化合物的產率有一定差異的原因是它們的化學活性和空間效應共同作用造成的.對已合成的N,O-二齒化合物,已經在嘗試合成其金屬配合物并將其用于催化丙交酯開環(huán)聚合反應,獲得了初步的研究結果,進一步的研究正在進行中.

[1] CARO C F,LAPPERT M F,MERL E P G.Review of Metal 1-azaallyl Complexes[J].Coordin Chem Rev,2001,219:605-663.

[2] CHAKRAVARTY A R,COTTON F A,SHAMSHOUM E S.2-Anilinopyridine Complexes of Dimolybdenum(II)and Ditungsten(II)[J].Inorg Chem,1984,23:4216-4221.

[3] BARR D CL EGG,W MULVEY R E,SNAAITH R.The Structural Isomers of{[Ph(2-pyridyl)NLi]·[OP(NMe2)3]}2: Dimeric Species with Alternative Central(LiN)2and(LiO)2Rings,the Latter Involving Unprecedented Neutral Bridging Oxygen Ligands[J].J Chem Soc Chem Commun,1984:700-702.

[4] POLAMOM,L ESKELA M.Synthesis and Crystal Structures of Phenyl(2-pyridyl)-amido Complexes of Zirconium(IV),Niobium(V)and Tantalum(V)[J].J Chem Soc Dalton Trans,1996:4345-4351.

[5] CL ERAC R,COTTON F A,DUNBAR K R,et al.Further Study of the Linear Trinickel(II)Complex of Dipyridylamide [J].Inorg Chem,1999,38:2655-2657.

[6] SPANNENBERG A,ARNDT P,KEMPE R.Yttrate-Mediated Ligand Transfer and Direct Synthesis as a Route to Amidopalladium Complexes[J].A ngew Chem Int Ed,1998,37:832-835.

[7] HICKS F A,J ENKINS J C,BROOKHART M.Synthesis and Ethylene Polymerization Activity of a Series of 2-Anilinotropone-Based Neutral Nickel(II)Catalysts[J].Organometallics,2003,22:3533-3545.

[8] J ENKINS J C,BROOKHART M.A Highly Active Anilinoperinaphthenone-Based Neutral Nickel(II)Catalyst for Ethylene Polymerization[J].Organometallics,2003,22:250-256.

[9] QIAN Y,ZHAO W,HUANGJ L.Synthesis,Crystal Structure,and Olefin Oligomerization Activity of Neutral Arylnickel (II)Phosphine Catalyst with 2-Oxazolinylphenolato N-O Chelate Ligand[J].Inorg Chem Commun,2004,7:459-461.

[10] FREDY S,PIEERE B,LUCIEN S.Dinuclear Nickel Complexes with Bidentate N,O Ligands:Synthesis,Structure,and Catalytic Oligomerization of Ethylene[J].Inorg Chem,2004,43:4234-4240.

[11] MARCELLO G,MATTEL T,MAURIZIO L,et al.A New Chiral N,N’,O-Donor Heteroscorpionate Ligand.Structures of Ni2+,Cu2+,Zn2+Complexes and Study of Solution Equilibria by Means of1H NMR/UV-Vis Titrations and EXSY NMR Spectroscopy[J].Inorg Chem,2007,46:3367-3377.

[12] WANG Z X,CHAI Z Y.Palladium(II)and Nickel(II)Complexes Bearing N,N,O-Chelate Ligands:Syntheses,Characterization and Catalysis in Heck and Kumada Coupling Reactions[J].Eur J Inorg Chem,2007:4492-4499.

[13] HICKS F A,BROOKHART M.Synthesis of 2-Anilinotropones via Palladium-Catalyzed Amination of 2-Triflatotropone [J].Org Lett,2000,2:219-221.

[14] HERRMANN W A,HAIDER J J,FRIDGEN J,et al.Chiral Molybdenum(VI)and Tungsten(VI)2’-pyridinyl Alcoholate Complexes.Syntesis,Structure and Catalytic Properties in Asymmetric Olefin Epoxidation[J].J Organomet Chem, 2000,603:69-79.

[15] PEREZ Y,MORANTE-ZARCERO S,ISBEL SIERRA I,et al.A Family of Titanium(IV)Alkoxo Complexes with N,O and O,O Chelating Ligands.Crystal Structure of[Ti(O-i-Pr)2{2-(-)-menthoxo-pyridine}2][J].Inorganica Chimica Acta,2007,360:607-618.

Synthesis of Pyridyl or Benzyl N,O-Bidentate Ligand Compounds

ZHANG Shuang-long,HUA Yu-peng,DONG Qing-chen, GUO Zhi-qiang,HAN Hong-zhang,WEI Xue-hong
(Institute of A pplied Chemistry,S hanxi University,Taiyuan030006,China)

A series of N,O-bidentate compounds were synthesized by the reaction of 2-methylpyridine or N, N-dimethyl-2-methylaniline deprotonated by n-butyllithium before with appropriate ketone or benzaldehyde and then hydrolysis.The method held the merits of mild condition,easy separation and purification of the products,and high yields.Also,the products were characterized by1H NMR and13C NMR.

N,O-bidentate ligand;synthesis;characterization

O621.3

A

0253-2395(2010)02-0255-04