Korean Chem. Eng. Res., Vol. 44, No. 4, August, 2006, pp. 417-423 아민고정화 MCM-41 염기촉매를이용한 Knoevenagel 축합반응 o Çg p 402-751 p}e n 253 (2006 7o 14p r, 2006 7o 25p }ˆ) Knoevenagel Condensation Reaction Using Amine-functionalized MCM-41 Base Catalysts Jung-Sik Choi and Wha-Seung Ahn School of Chemical Engineering, Inha University, 253, Yonghyun-dong, Nam-gu, Incheon 402-751, Korea (Received 14 July 2006; accepted 25 July 2006) k e s v MCM-41 vv~ ol l p aminopropyltrimethoxysilane(apms)p eˆ m rs m t m pp Knoevenagel pp l r p r m. Methyltrimethoxysilanep }, APMS m o o e l 2 k r eˆ MCM-41 (BAPM) rs, MCM-41 p q OH r p p k rp p k p lr l p TONp lp pl. Žl p l p kp k p r MCM-41p, p p p tl, pr k p p p l p m m rp k. rs tl BAPMp p q n m. h Abstract A series of amine functionalized MCM-41 catalysts were prepared by aminopropyltrimethoxysilane grafting and their catalytic performance in Knoevenagel reaction of selected substrates was investigated. Water resistant and catalytically active amine grafted MCM-41 was prepared by post-synthetic silylation using methyltrimethoxysilane ; hydrogen bonding of the water molecules formed during the condensation reaction to the active N group was suppressed, which led to high TON of the reaction. Amine functionalized MCM-41 prepared by coating method produced high conversion, but the TON of the catalyst was much lower than that of the amine grafted MCM-41; pore volume of the functionalized MCM-41 decreased substantially and large portion of the immobilized amine is believed to be hydrogen bonded to each other, which can result in decrease in the basicity of the N group. A secondary amine group was prepared by room temperature condensation between aminopropylsilane and chloropropylsilane, and the MCM-41 grafted with the secondary amine group demonstrated the highest catalytic activity among the catalysts prepared. Key words: Mesoporous Silica, Aminopropyltrimethoxysilane, Silylation Solid Base Catalyst, Knoevenagel Condensation 1. sp kˆ p, m p p v p, p, p p o p m l p p lv. p p p p m l v pv, p m p n p p p n l q p ep p rp r, p p rv kp p n p. p p p ~ re pv, ~m To whom correspondence should be addressed. E-mail: whasahn@inha.ac.kr tp p p ˆ l p d l p pp rnp l, ~ l l rp l l, ~ p n 100 n rp p, ~ m p n n rp l kv v erp [1-3]. ~ l l Pines l p m p p v pp Na/Aluminal p v eqp [4], k, k p pm rm p l l p v l. pm rm p p n, k p m l m p k p pm l vl Cs +, Rb +, K +, Na +, Li p + p [5]. 417
418 reëk d k p v p m v eˆ k r p, NaOHm Na p k l v e rs Na/NaOH/aluminam KOHm K p k l ve rs K/KOH/alumina ~ m p, m rp p Nam Kp pm l p [6]. pr vp ~m l m p p v p p p p n pp l ~ m p rp r p q l t p lp, l p k m l p lv Michael p, Knoevenagel p p ~ m n p m pp ~ l t p pp, o l rr p ep vt p [7-10]. rp k l p lr m monoglyceridep p k p s vp pn l p e lp, α-monoglyceride p p 90Í p p l, l p q nl k rrp pp ltl [11, 12]. Choudari p diamine p p l Knoevenagel pp m. monoaminel p p n m, k Š s k p k p v m [13]. Rodriguez p quarternary ammonium hydroxide MCM-41 l e chromenep p e m. p m p l p chromene coumarinl ˆ r l, m p sr l p p ˆ sr m [14]. l l ~ m n pl tn r p p t l p m rp r [1, 2, 8] tp p r } p l q m. p rp aminopropyltrimethoxysilane(apms)p s e p MCM-41l r l p } p l t m pp Knoevenagel pp p p p s m. 2. 2-1. { 2-1-1. q p v MCM-41 vv~p q p v MCM-41p Lindlar [15]p l l rs m. p qp o l, C 16 TACl(hexadecyltrimethylammonium chloride)m C 12 TABr(dodecyltrimethylammonium bromide)p l s r n m, mesitylene Ž}r n m. e op p e (HS-40, Ludox)m np e (Cab-O-Sil M5) l n m. kp p k. SiO 2 : 0.542 NaOH : 0.116C 16 TMACl : 0.025C 12 TMABr : 0.75 mesitylene : 30.3H 2 O. kp ml 30 eˆ 373 Kl 4p l. t lkr p v eˆ o l, ph k p 24e 11.0±0.1p 3 sr. vp l v } 353 K v l s m. s e 823 Kl 4e l s p ll. o44 o4 2006 8k 2-1-2. APM(aminoproplysilane grafted MCM-41)p rs MCM-41p 353 K, v l s. s e 1.5 g aminopropyltrimethoxysilanep 15 ml Š ll eˆ 6e k. e l ethanol } 353 Kl s. 2-1-3. SAPM(silylated aminopropylsilane grafted MCM-41)p ol rs APM e p methyltrimethoxysilanep n l om p p l } rp ~ e rs. 2-1-4. CAPM(coated aminopropylsilane MCM-41)p 353 K, v l s e 100 ml v l 3e k p,, l p rp ~ p o e l. Deanstark q pn l rlp e p p 1.0~1.5 ml r. p e kp, p 3-aminopropyltrimethoxysilanep ~ eˆ 4e k l. e l, } 353 Kl s. 2-1-5. BAPM(bridged aminopropylsilane grafted MCM-41)p 3-chloropropyltrimethoxysilane 3-aminopropyltrimethoxysilanep Š ll 8e k ml. r } MCM-41 l p kp ~, s l 6e k l,. e l, } 353 Kl s. 2-2. { m v X r p X-ray diffractometer(rigaku, Miniflex, Target: CuKα, Filter: Ni) n l m. r rp o r} r(1.4 Pa. p p k, 383 K l 10e )p Micromeretics ASAP 2000 automatic analyzer n l v p m. BET p e p rp r m BJH(Barrett-Joyner-Halenda) p r m. s v l p o vp r p p o Porapack PQS lr (TCD) q o (CE instrument) pn l CHNS o p m ( n ol p ). FT-IR spectrum(bomem MB104) p e KBrl k eˆ pelletp l 500~1,400 cm ol 1 Œ r m., p ˆ p o TEM(Phillips, CM 200)p n m. 2-3. Knoevenagel } m s k o v p r ˆ o k m methylene p pn l knoevenagel pp m. p m m s l 2t q 2 d n m. pp Š l 15 ml n l 323 Kl 6e k m. 20 mgp n m, p p 1:1p 10 mmol p aldehydem 10 mmolp methylene p n m. k benzaldehyde(99í, Aldrich), butyraldehyde(99.5í, Aldrich) p n m, methylene p ethyl cyanoacetate(98í, Aldrich)m diethyl malonate(97í, Aldrich)p n m. p p n-decane(99í, Aldrich)p t v l, pm (FID)m HP-5 capillary p d Š (HP 5890) n l m.
k r MCM-41 m pn Knoevenagel p 419 Fig. 2. TEM images of the pore-enlarged MCM-41. Fig. 1. XRD patterns(a) and N 2 adsorption-desorption plot(b) of enlarged MCM-41. 3. y 3-1. Functionalized MCM-41m r vv~ pn q p v MCM-41p XRD v m p Fig. 1l ˆ l. Fig. 1(a) p XRD Ž l 1.0~3.0 ol MCM-41p s s o ˆ (1 0 0) plp, r p 2θ mll ~ p, (1 1 0), (2 0 0), (2 1 1) p ˆ p p ˆ v kk. 832 Kl } l r r p q m. p s vp long range order mp, p m q lpp k pl. Fig. 1(b)l v l p s vp m p ˆ l. vp s vp p ˆ r rp IV ˆp p mp SBA-15 p q s vl p hysteresis loopp ˆ l. p 4.8 nm, BET r 894 m 2 /g BJH p 1.32 cm /gp p 3 ˆ l. q p v MCM-41p evrp ˆ p o l TEM p mp Fig. 2 l ˆ l. vp p p Fig. 2(a)m p rp s lp, Fig. 2(b)m p p kp lp rp p l v k }p pl. p p q ˆp, q p v MCM-41p p rp p rs MCM-41l l 2 p p p s p v pl, rp sm rp s q ppp k pl. q p v MCM-41p k p lp o e v } mp, r p Scheme 1l e m. n MCM-41p l sq Si-OH pn l k p o e p l APM (aminoproplysilane grafted MCM-41) e m, APMp q Si-OH silylation } l SAPM(silylated aminopropylsilane grafted MCM-41) m. p eˆ e p FT-IR Fig. 3l m. Fig. 3(a) p q MCM-41p IR p. p MCM-41 p 960 cm -1l p Si-OH ˆ. p o e p l rp p Fig. 3(b), (c)m p r. w CAPM(coated aminopropylsilane on MCM-41) p Feng [16]p thiolp l p o e p p pn l MCM-41p l p eˆ p k p lp o e vl rn l p. v p BAPMp m o e k p o e p r } k p m m mp p o m. p p l k p kyl o e p 2 k r ~ rs p MCM-41 l e m. Korean Chem. Eng. Res., Vol. 44, No. 4, August, 2006
420 reëk d Fig. 3. FT-IR spectra of the pore-enlarged MCM-41(a), amine functionalized MCM-41(b), and silylated amine functionalized MCM-41(c). Scheme 1. Functionalization procedure of grafting and silylation (a), coating (b), and secondary amine grafting (c) method. p k p p eˆ k MCM-41p p s o v p r,, p r l Table 1l e m. p vpl MCM-41l CAPMp q l p m, e s j p m. p k MCM-41p p o e p pp rp q p lv p k pl. Table 2 MCM-41l o p r p o EA(elemental analysis) p. APMp C/N(carbon/nitrogen)p pp 3.57p p k o e l l p p k Table 1. Textural properties of MCM-41 before and after functionalization Sample* Pore diameter (nm) a Surface area (m 2 /g) Pore volume (cc/g) Parent 4.8 894 1.32 APM 4.4 618 0.97 SAPM 4.2 584 0.88 CAPM 2.7 478 0.57 BAPM 4.2 538 0.87 *refer to scheme 1 for APM: grafting aminopropyl-mcm-41, SAPM: silylated APM, CAPM: coated aminopropyl-mcm-41, BAPM: bridged aminopropyl-mcm-41. a calculated by BJH method using the desorption branch p MCM-41p p l k m l p, SAPMp MCM-41 p q OH trimetyl p p o e p p silylationp p lr C/N pp 4.42 v m. CAPMp C/Np pp 3.76p p k, le p k p o e p p MCM-41p p pp r l, e l l C, Np r p p p k p k p k p l p Ž. BAPMl C/N Table 2. Elemental analysis of various amine-functionalized MCM-41 catalysts Sample N (wt ) C (wt ) N (mmol/g) C (mmol/g) C/N (mol ) APM 2.87 8.77 2.05 7.31 3.57 SAPM 2.50 9.50 1.79 7.92 4.42 CAPM 4.93 15.8 3.52 13.2 3.76 BAPM 1.97 8.87 1.41 7.39 5.22 atomic percent of nitrogen per gram catalyst atomic percent of carbon per gram catalyst a b o44 o4 2006 8k
k r MCM-41 m pn Knoevenagel p 421 Scheme 2. Reaction pathway over the heterogeneous amine-grafted catalyst[9]. pp 5.59 m 2 k p lp n m 6(Scheme 1(c) s) p m. 2 k p 90Í p l v k p 1 k p sq p l. op q p s l, p q MCM-41p p rp lp 4.8 nmp p s p v p, p MCM-41 e l k p o e p l eˆ r,, p p p., l p p l, Ž p n 3.52 mmol/gp q p kp p l, APMp C/N pp 3.57 p l r m, silylation C/N p pp v p l. 3-2. Knoevenagel } m Š vp p p o l k m methylene p p l Knoevenagel pp m. MCM-41p l eˆ k p m rp q n Knoevenagel pp Scheme 2l e m p k k p p p p methylene p p l p pp v. p l methylene t ~ p p l p t ~, t pmp q p p k p p lv pp p. 2 k p n o ƒ vp v p m p. k s k (benzaldehyde)m v s k (butyraldehyde) n m, methylene p pka p ECA(ethyl cyanoacetate)m r pka p DEM(dimethyl malonate) n l pp p kk k. pm p s p k m s p methylene p Table 3. Conversion and TON of the various amine-grafted catalysts Conversion TON a Benzaldehyde Butyraldehyde Benzaldehyde Butyraldehyde ECA b DEM c ECA DEM ECA DEM ECA DEM Parent 0 0 0 0 0 0 0 0 APM 88 10 94 33 215 24 229 80 SAPM 94 13 100 35 263 36 279 98 CAPM 92 8 93 28 131 11 136 40 BAPM 92 19 100 37 329 67 355 131 Reaction temperature 50 o C, time 6 h a turnover number : moles of product per moles of amine in catalyst b ECA : ethylcyanno acetate, c DEM : diethyl malonate Korean Chem. Eng. Res., Vol. 44, No. 4, August, 2006
422 reëk d n l Knoevenagel pp Table 3l r m. r~rp pp p s k p r pp v s k l s j lr, DEMl ECA p mp, r pp o k. p 2 v npp p, p~r l p rp p~r p qp v s k pl o p k p. methylene p pm l p p p r rp. v, pmp d pka p p ECA DEMl p p n m. p k p s l p r pp p methylene s l p r p p p p k, k k p p e l pl methylene l pmp lv p p r pp k pl., q p v MCM-41p k l pp p p k. k } v kp MCM-41 p pp r v v kk, p p p ECA n mp k p reˆ silylationp l l q Si-OH p r SAPMp q n r pp ltl. l p p p DEMp n mp BAPMp q n llr. p p rp TON(turn over number)p n l, BAPMl q n m, pp SAPMp p p k. CAPMp r pp kp, l k p kp SAPM p BAPMl 2 p k TONp q p ˆ l. p r pp ltl CAPMp o r p p p q p po p kp k p p l pr k p kp v m, p pr k p rp sq k l l p lr p. p ECAm DEMp l kp e ˆ. ECA p n mp BAPMp APM p r pp ltl CAPMp DEM p p n mp, m p r pp ltl. p pka DEMp r(k )p k rp l p v p. p kp, CAPMp k p p p l o v, pr k p p p p r m lv p. o Yang p k s p k p HMSl pp m, p k p kp v p p lv p m [17]., rp p kp k p p SAPMl APMl p r pp l, BAPMl vl p TON ltl. l k p eˆ m tp p p ˆ l p d, pp n p t p l k rp d p. Macquarrie p Dean-Stark q pn l p tl p r pp v m,, p r l k 1.5 p p r p p m [8], Luechinger p APM, SAPM o rs l p p lkr p m, SAPM p e vv~p rp l APMl lkr p v m m [18]. p po l OH r C/N pp k p r p l n SAPMp BAPMp rp p p n p lv., o44 o4 2006 8k BAPMp e qn p pp p n 2 k p [19], p~r p l ˆ l v p., pp pl v kp p 1 k p rp ˆ ov l o r p p ov. 4. p q MCM-41p m, XRD p q s s p m. v p r(894 m 2 /g), p (4.8 nm), p (1.32 cc/g) p r m. k p o e p pn l MCM-41 l m. Coating p CAPMp 2 p p k p p l p p p mp, eˆ MCM-41p, rp p kp k pp pr k p p k p p r eˆ npp l. SAPMp p rp p eˆ APMl p p n m. p p OH r l k p p p, pe l p k p p v p. BAPMp q p C/N pp l p p p v, r vp p rp p f q p TON ˆ l., o e r } rl p p 2 k p p p tn opp. l q p r l l l l p l vo lp (R01-2003-000-10382-0) vol. y 1. Hattori, H., Heterogeneous Basic Catalysis, Chem. Rev., 95(3), 537-558(1995). 2. Ono, Y. and Baba, T., Selective Reactions over Solid Base Catalysts, Catal. Today, 38(3), 321-337(1997). 3. Tanabe, K. and Hlderich, W. F., Industrial Application of Solid Acid-base Catalysts, Appl. Catal. A, 181(2), 399-434(1999). 4. Pines, H. and Eschinazi, H. E., Studies in the Terpene Series. XXIV.1 Sodium-catalyzed Double Bonds Migration and Dehydrogenation of d-limonene, l-α-phellandrene and of 2,4(8)- and 3,8(9)-p-Menthadiene2,2a, J. Am. Chem. Soc., 77(23), 6314-6321 (1955). 5. Mortier, W. J., Zeolite Electronegativity Related to Physicochemical Properties, J. Catal., 55(2), 138-145(1978). 6. Tanaka, K., Yanashima, H., Minobe, M. and Suzukamo, G., Characterization of Solid Superbases Prepared from γ-alumina and Their Catalytic Activity, Appl. Surf. Sci., 121-122(2), 461-467 (1997). 7. Lin, X., Chuah, G. K. and Jaenicke, S., Base-functionalized MCM-41 as Catalysts for the Synthesis of Monoglycerides, J. Mol. Catal. A., 150(1-2), 287-294(1999). 8. Macquarrie, D. J., Clark, J. H., Lambert, A., Mdoe, J. E. G. and
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