柴油加氢装置中氢气管道的材质选择

综合分析了某柴油加氢装置中氢气管道在反应部分（包括压缩机）、循环氢脱硫、低分气脱硫和膜分离部分,根据其不同的设计条件,综合考虑其设计温度,设计压力及其介质特性等因素确定工艺管道的材质。     

Side reactions in solid-phase peptide synthesis and their applications

Side reactions in peptide synthesis indicate steps needing improvement as well as opportunities for structural diversification in combinatorial design. Among the side reactions observed in this study, transesterification of Boc-Glu(OBzl) occurred in TMAH-catalyzed resin attachment, leading to Boc-DKKREE(OMe) in solid-phase synthesis of Boc-DKKREE. Acetylation of Boc-Arg(NO₂)-resin occurred during resin capping with Ac₂O/Et₃N, leading to GPR(Ac) in GPR synthesis. His- and Lys-modification occurred during GHRPLDKKREE cleavage from resin by Pd(OAc)₂-catalyzed hydrogenation in DMF. To verify these side reactions, model experiments were performed, which indicated rapid transesterification of Boc-Glu(OBz1) in methyl. isopropyl, or tert-butyl alcohol into the corresponding ester by TMAH, but not by Cs. This TMAH ability was used to devise a convenient procedure for peptide cleavage. TLC studies of acetylation showed that both Boc-Arg(NO₂) and Boc-Arg(Tos) were stable to Ac-Im treatment, but were modified by Ac₂O/Et₃N. Since transfer hydrogenation of Boc-His(Bzl) and Boc-Lys(Z) in HCOOH or ammonium formate did not generate the formylated side-products of catalytic hydrogenation, DMF and not its decomposed product, HCOOH, appeared involved in side-chain modification. Elimination of the side reactions, by using Cs-derived Boc-Glu(OBzl)-resin for peptide synthesis and catalytic hydrogenation in NMP-HOPr for peptide cleavage. increased the GHRPLDKKREE yield by 1/3. On the other hand, the side reactions provided modified peptides, whose bioassays revealed different importance of the modified side-chains. © Munksgaard 1996.     

茂钛络合物—纳米NaH体系催化苯乙烯氢化

茂钛络合物，以纳米ＮａＨ为助催化剂催化苯乙烯氢化，初速率为３．７×１０＾３－８．３×１０＾３ｍｏｌ／（ｍｏｌ．ｍｉｎ）（Ｈ２／Ｔｉ），催化效率为６．４×１０＾３－１８．５×１０＾３ｍｏｌ／ｍｏｌ（Ｈ２／Ｔｉ），均高于文献的其他２茂钛催化体系，考察了不同温度对催化反应的影响，反应温度在２７５－３１５Ｋ时，活化能为２０．３ｋＪ／ｍｏｌ，与催化体系活性高一致。     

Tryptophan reduction and histidine racemization during deprotection by catalytic transfer hydrogenation of an analog of the luteinizing hormone releasing factor

(d -Trp)⁶-LHRH:pGlu-His-Trp-Ser-Tyr-d -Trp-Leu-Arg-Pro-GlyNH₂ was prepared by solid-phase peptide synthesis using the nitro group to protect the guanidine side chain of the arginyl residue. Removal of the side-chain protecting groups was carried out by catalytic transfer hydrogenation (CTH) using palladium acetate/ammonium formate or palladium on charcoal/formic acid. We show in this paper that this deprotection method induces i) reduction of the tryptophan residue and ii) epimerization at the histidine level (with palladium acetate/ammonium formate). Despite the formation of significant amounts of reduced peptide. CTH enabled us to obtain (d -Trp)⁶-LHRH in relatively good yield.     

POLYUNSATURATED RUMINANTS

Timed-release linoleate passes through the rumen, leaves microflora irate, unable to hydrogenate, foiled by Australian scientifical acumen.     

聚钛氨烷—铂—锰双金属络合物催化的苯酚选择性氢化反应的研究

制备了二氧化硅负载的聚钛氨烷－铂－锰双金属络合物。结果表明，该催化剂在常温常压下对苯酚具有较高的催化氢化活性和选择性，在双金属络合物中，缺电子的锰离子作为Ｌｅｗｉｓ酸吸附点对环己酮分子中的羰基具有很强的吸附能力，可明显抑制环己酮在铀金属表面的吸附和进一步氢化，环己酮在终产物中的含量可达４９．２％，研究了Ｎ／Ｐｔ／Ｍｎ摩尔比，反应温度，时间和溶剂等对催化活性及选择性的影响，此催化剂有良好的稳定性，重     

液相苯加氢反应的内扩散阻力分析

采用NCG工业新型苯加氢催化剂(Ni/Al2O3),通过消除外扩散和内扩散影响,在反应温度433~473 K和氢压0.6~3.3 MPa下,对液相苯催化加氢制环己烷的反应动力学进行了研究。结果表明,液相反应中苯的反应级数为0,氢的反应级数几乎为1,因此氢在催化剂内的传质过程是形成内扩散阻力的主要原因。由内部效率因子和Thiele模数可知,粒径小于0.150 mm时才能消除内扩散影响,说明该催化剂具有较高本征反应活性。通过Thiele模数的定义式,求得氢液相有效扩散系数。由Wilke-Chang方程得到综合扩散系数,进而通过Thiele模数定义式求得催化剂曲节因子为3.12。通过模拟得到液相中氢在不同粒径颗粒内的浓度分布曲线,说明氢的内扩散阻力是苯加氢反应的控制因素。     

Electrocatalytic hydrogenation of alkenes on LaNi5 electrodes

In this paper a new electrocatalytic hydrogenation process is reported based on the use of LaNi₅ electrodes. The charge/discharge of hydrogen within the intermetallic compound through cyclic voltammetry experiments was observed using a powder microelectrode in classical aqueous KOH medium, as well as in other buffered aqueous or hydro-organic media. Most voltammograms are modified in the presence of unsaturated compounds, which indicates that a hydrogenation reaction occurs. Electrocatalytic hydrogenation on a preparative scale was carried out with three unsaturated compounds taken as models (methyl vinyl ketone, 1-decene, 5-hexen-2-one) and it was found that only the CC bond is hydrogenated with Faradaic efficiencies up to 100%.     

2-酰氨基-3-芳基丙烯酸甲酯的不对称氢化反应

以单齿磷配体(S)-MonoPHOS和［Rh(COD)₂］BF₄作为催化剂,研究2-酰氨基-3-芳基丙烯酸甲酯类化合物中的氨基保护基对其不对称催化氢化反应的影响。最终经水解等操作,2-酰氨基-3-芳基丙烯酸甲酯类化合物的不对称氢化反应以63%~92%的收率得到相应的D-苯丙氨酸及其衍生物。     

美替诺龙醋酸酯的合成

目的　由 17β 乙酰氧基 5α雄甾 1 烯 3 酮 (1)经 5步反应合成蛋白同化激素美替诺龙醋酸酯 (17β 乙酰氧基 1 甲基 5α雄甾 1 烯 3 酮 ,6 )。方法　 17β 乙酰氧基 5α雄甾 1 烯 3 酮 (1)在酸的存在下与NBS反应 ,得2 β 溴 1α ,17β 二羟基 5α 雄甾烷 3 酮 17 醋酸酯 (2 ) ,化合物 (2 )用H2 /活性镍催化氢解 ,得 1α ,17β 二羟基 5α 雄甾烷 3 酮 17 醋酸酯 (3) ,然后在对甲苯磺酸的催化下化合物 (3)与甲醇作用 ,得 3,3 二甲氧基 5α 雄甾烷 1α ,17β 二醇 17 醋酸酯 (4 )。化合物 (4 )经铬酐 硫酸氧化 ,得 17β 乙酰氧基 3,3 二甲氧基 5α 雄甾烷 1 酮 (5 ) ,再经格氏反应和乙酰化反应 ,制得 17β 乙酰氧基 1 甲基 5α 雄甾 1 烯 3 酮 (美替诺龙醋酸酯 ,6 )。由化合物 1到 6的总收率为 48.7%。结果　此法以较高收率合成了美替诺龙醋酸酯。结论　该合成法有适用于工业化生产的前景