α-萘酚的绿色合成法

研究了萘一步催化氧化合成α-萘酚的新方法,选用了有较大孔径的分子筛（FeVPI-5）为催化剂,过氧化氢为氧化剂。重点讨论了溶剂、进料比、催化剂用量、反应时间和反应温度对萘羟基化反应的影响。结果表明：以丙酮为溶剂,n（H2O2）：n（C10H8）=1、0,催化剂用量为萘的10％（质量百分比）,反应时间10h,反应温度55℃,α-萘酚的最高产率可达20、4％。该法工艺简单、原料易得,而且没有三废,是一种理想的环保方法。     

过氧化氢氧化萘一步法合成萘酚

在γ-Al2O3为载体的金属铁氧化物Fe2O3催化剂存在下,以丙酮作溶剂,研究了过氧化氢氧化萘一步法合成萘酚的新方法,试验了各条件对氧化反应的影响。结果表明,n(H2O2):n(C10H8)为1∶5～7,m(cat):m(C10H8)为1:5～6,在50～55℃下,反应7～8h,可获得较好的收率。该法工艺简单,原料易得,无三废排放,易于工业化生产,是一种绿色化学合成技术。     

相转移催化H2O2环氧化环己烯合成环氧环己烷

对反应控制相转移催化剂制备方法进行了改进,催化剂产率可达94%,并用红外光谱(IR)和元素分析对催化剂进行了表征;将催化剂用于以w(H2O2)=34.5%为氧化剂,以质量分数76.7%的工业粗环己烯为原料合成环氧环己烷;探讨了反应时间、反应温度、环己烯与H2O2的摩尔比、催化剂用量、溶剂用量等因素对反应的影响。获得的较佳合成条件(以0.08 mol H2O2计)为:反应温度40℃,反应时间90 m in,催化剂用量0.6 g,n(C6H10)∶n(H2O2)=2.5∶1,溶剂1,2-二氯乙烷70 mL。该条件下环氧环己烷平均选择性为96.1%,环氧环己烷的平均收率达91.7%。将回收的催化剂用于反应,环氧环己烷的平均选择性和平均收率分别为95.3%和90.9%。     

干燥温度及反应条件对SiO_2-TiO_2复合气凝胶环氧化催化性能的影响

通过溶胶凝胶-常压干燥法制备不同干燥温度的Si O2-Ti O2复合气凝胶,将其用作以N,N-二甲基甲酰胺(DMF)为溶剂,H2O2[n(H2O2)=30%]为氧化剂的苯乙烯环氧化催化剂,结合XRD、UV-vis、FT-IR等表征手段研究了干燥温度对其催化性能的影响。同时考察了双氧水用量、反应温度、反应时间、催化剂用量等反应条件对反应性能的影响。结果表明,干燥温度提高,催化剂性能降低,最佳干燥温度为120℃。最佳反应条件为:n(H2O2)/n(苯乙烯)=0.5,反应温度为60℃,反应时间为6 h,催化剂质量为0.25 g。     

氢型β沸石负载磷钨酸在金刚烷合成中的应用

采用过量浸渍法制备了一系列的氢型β沸石(Hβ)负载磷钨酸(PW),用于桥式四氢双环戊二烯(endo-TCD)异构化合成金刚烷(ADH)反应.X射线衍射(XRD)、氨程序升温脱附(NH3-TPD)等表征方法对催化剂进行表征.表征结果表明:PW在Hβ表面呈高度分散状态,10%PW/Hβ具有最大的酸量.对异构化反应中的焙烧温度、反应温度、时间、初压、溶剂用量和催化剂用量等工艺条件进行了考察,得出在适宜的操作条件下即催化剂10%PW/Hβ焙烧温度350℃、反应温度240℃、n(环己烷)/n(endo-TCD)=5、m(催化剂)/m(endo-TCD)=0.8、初压0.8MPa、反应时间3 h,endo-TCD转化率达到99.3%,金刚烷的收率达到22.4%.     

豆甾醇催化氢化制备谷甾烷醇

以豆甾醇为原料、Pd/C为催化剂,通过常压催化氢化制备谷甾烷醇。实验确定了最佳反应条件,Pd/C催化剂用量w(Pd)=0 1%(相对于豆甾醇质量),反应溶剂为异丙醇,反应温度82℃,反应时间8h,原料量比n(异丙醇)/n(豆甾醇)=80,豆甾醇转化率94 85%,产品w(谷甾烷醇)=93 31%。     

相转移催化合成二环已基二硫醚

采用相转移催化剂,氯代环已烷与二硫化钠溶液反应合成了二环已基二硫醚。考察了相转移催化剂的种类、原料摩尔比、反应温度等对反应的影响,比较了相转移催化与溶剂法合成的反应结果。得到的最佳反应条件为:以PTC3为相转移催化剂,反应温度96℃,n(Na2S)∶n(S)∶n(C6H11C l)=1∶0.8∶0.8,氯代环己烷的转化率为98.8%,二环已基二硫醚的选择性为81.4%。与溶剂法相比,反应时间由12~15 h缩短到10 h,收率提高了10%,避免了因使用溶剂带来的后处理问题。     

超声波促进浓H2SO4改性活性炭催化合成β-萘甲醚

在超声波辐射下,以活性炭负载浓硫酸作催化剂,催化合成了β-萘甲醚。考察了超声波辐射功率、辐射时间、无水甲醇用量、催化剂用量等因素对合成工艺的影响。确定了最佳反应条件:n(β-萘酚)∶n(无水甲醇)=1∶6,x(催化剂)=7%,超声波辐射功率200W,反应时间为15min,反应温度为80℃,在该条件下,β-萘甲醚产率为98.3%。该方法条件温和、操作简便高效。     

辅酶Q_0的合成

采用3,4,5 三甲氧基甲苯为原料,w(H2O2)=27 8%为氧化剂合成辅酶Q0,考察了催化剂、反应温度、原料配比、溶剂等因素对反应的影响,得到最佳反应条件为:n(3,4,5 三甲氧基甲苯)∶n(H2O2)=0 28∶1,m(磷钼酸)∶m(3,4,5 三甲氧基甲苯)=0 5∶100,反应温度40℃,反应时间2h。采用正交实验对反应条件进行优化并进行了重复实验,得到稳定的收率为49%。     

One-pot Synthesis of N-[Pheny1-(2-hydroxy-napthalen-1-y1) -methy1]-acetamide Catalyzed by SnCl4 · 5 H2O

采用SnCl4·5H2O为催化剂催化2-萘酚、苯甲醛和乙酰胺的三组分一锅法类Ritter反应合成了1-乙酰胺基苯甲基-2-萘酚(AAN).考察了原料配比、催化剂用量、反应温度和反应时间等因素对AAN收率的影响,确定了适宜反应条件为:n(2-萘酚)∶n(苯甲醛)∶n(乙酰胺)=1∶1.4∶1,催化剂用量为反应物总质量的6％、85℃反应35 min,AAN的收率可达96.2％.该合成工艺路线简捷,催化剂价廉易得,催化活性高,使用方便,反应条件温和,收率可观.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.