共查询到19条相似文献,搜索用时 125 毫秒
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手性唑啉-Ti(Ⅳ)配合物催化硫醚的不对称氧化反应研究 总被引:3,自引:0,他引:3
设计合成了系列唑啉-Ti(OiPr)4配合物催化剂, 首次成功地用这类催化剂催化一系列硫醚的不对称氧化, 获得了e.e.值为70%~96%的亚砜; 考察了溶剂、催化剂用量、抗衡离子等因素对反应的影响. 相似文献
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用循环伏安法和计时电量法等电化学方法研究了配体2,6-二(5-甲基噁二唑)吡啶(DMOP)在玻碳电极(CCE)上的电化学行为.结果表明:在-0.3~-1.3 V电位范围内及0.1 mol/L四丁基高氯酸铵(TBAP)的N,N-二甲基甲酰胺底液中,DMOP于-0.8 V(vs.SCE)左右处产生一对准可逆的氧化还原峰,还原峰电流和氧化峰电流与扫描速率的平方根(v1/2)呈良好的线性关系,表明DMOP在GCE上的伏安行为是一受扩散控制的电化学过程,其电极反应过程是单电子转移,传递系数α为0.56,扩散系数为2.84×10-5 cm2/s,电极反应速率常数Kf为0.89 cm/s.利用循环伏安法研究了该化合物对过渡金属离子的识别作用,发现该化合物在一定浓度下对Pb2 有较好的选择识别性. 相似文献
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蒽酮1和氯甲基吡啶盐酸盐2在甲苯中回流反应生成10,10-二吡啶甲基-9(10H)蒽酮(3),收率63%~68%;3用硼氢化钠还原生成10,10-二吡啶甲基-9,l0-二氢蒽-9-醇(4),收率87%~90%;蒽醇4在酸催化下发生歧化反应,得到还原产物10,10-二吡啶甲基-9,10-二氢蒽(5)和氧化产物蒽酮3.该歧化反应受催化剂、溶剂和反应温度等影响.当蒽醇4用三氟化硼为催化剂、甲苯为溶剂、回流反应,5的收率达到74%.所合成的新化合物都经1H NMR,13C NMR,MS和元素分析表征确认. 相似文献
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设计合成了系列:唑啉-Ti(OiPr)4配合物催化剂,首次成功地用这类催化剂催化一系列硫醚的不对称氧化,获得了e.e.值为70%~96%的亚砜;考察了溶剂、催化剂用量、抗衡离子等因素对反应的影响. 相似文献
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Meng F. Q. Lu M. K. Yang Z. H. Zeng H. 《Journal of Thermal Analysis and Calorimetry》1998,52(2):609-613
The thermal behavior of two new non-linear optical (NLO) materials, urea-(D) tartaric acid (UDT) and urea-(DL) tartaric acid
(UDLT) were studied by using DSC, TG and TMA. The results show that: 1) The two crystals have different melting points but
similar decomposition temperatures due to the influences of intermolecular forces, which is attributed to the stereo effects
of (D)-tartaric and (DL)-tartaric acid molecules; 2) There was only thermal expansion and no thermal contraction when the
UDT and UDLT crystals were heated; 3) There was no phase transition within the measured temperature range; 4) The thermal
expansion of the UDT and UDLT crystals shows a small anisotropy; 5) The specific heats of UDT and UDLT change linearly with
temperature in the measured temperature range and the value for UDT is 1.321 J g-1 K-1 at 320 K while the specific heat of
UDLT is 1.357 J g-1 K-1 at the same temperature.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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酒石酸衍生物促进的醛酮不对称烷基加成反应研究进展 总被引:1,自引:0,他引:1
酒石酸分子具有含两个手性碳原子的对称结构, 且价廉易得. 因此, 酒石酸及其衍生物在不对称合成领域被广泛应用, 其中α,α,α’,α’-四苯基-2,2-二甲基-1,3-二氧环戊烷-4,5-二甲醇(简称TADDOL)及其类似物、手性酰氧硼烷(简称CAB)等促进的不对称催化反应研究得更为深入和细致. 综述了近年来TADDOL和CAB等作为手性配体在二乙基锌试剂与醛酮、烯丙基有机金属试剂以及烷基铈试剂与醛的加成反应中的应用, 同时简要地介绍了各手性配体的催化效果. 相似文献
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Su Yun LIU Dao Fei HUANG Hai Hong HUANG Liang HUANG* Institute of Materia Medica Chinese Academy of Medical Science & Peking Union Medical College Beijing 《中国化学快报》2000,11(11)
Fostriecin(CI-920) 11 a potential anticancer agent presently in phase I clinical trials at NCI is a novel phosphate ester produced by Streptomyces pulveraceus. Scheme 1 1 2 3 5 4 Synthesis of C10 epimer of compound 1 had been reported by Just G2. during the determination of its structure. On the basis of Just’s synthesis, a revised retro-asymmetric synthetic route of Fostriecin (scheme 1) was designed here of which compound 3 was synthesized from 5 with C3 in R configuration correspondi… 相似文献
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《Analytical letters》2012,45(9):1735-1747
Abstract A new chelating resin has been synthesized by introducing a quinaldinic acid amide group into styrenedivinyl benzene (8%) copolymer beads. The resin is stable in fairly strong acids or alkali and has been characterized by elemental analysis for nitrogen and from i.r. spectra. The water regain value is 0.37g/g. The sorption patterns of Na(I), K(I), Ca(II), Mg(II), Pb(II), Cu(II), Ni(II), Zn(II), Cd(II), Hg(II) and Fe(III) on the chelating resin have been studied as a function of pH. The resin selectively sorbs Hg(II) ever a wide pH-range of 2.5–7.6 with high efficiency. The maximum exchange capacity for Hg(II) is 1.98 mmols g?1 at pH 5.5. Over 99% of Hg(II) sorbed has been recovered by using 10% thiourea in 1M HClO4 both by batch and column operations. The has been utilized in the preconcentration and recovery of Hg(II) from industrial and laboratory waste water. 相似文献
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EPOthiloneA(l)andB(2)aresecondarymetabolitesofmyoxobacteriasorangiumcelulosumandwerefirStisolatedbyHcfco'sgroup."=EpohlilonesPOssesspotentantifungalachvity.'MoStimPOhallhy,MerckscientistsdiscoveredthatepothiloneAandBhaVeallthebiologicaleffectsoftaxolwithtilesamemeclwnismofactioll,'buttheStruchlTCsaretotallydifferentfromcool.ThesebiologicalanalogUesoftaxolrepresentanewleadinthesearchforantitUmortherapeuticagentswiththesameachonmechedsmastaxol.SeveralgroupshaVereportedtheirapproachtosyn… 相似文献
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手性磷酸催化剂在不对称合成中的应用 总被引:2,自引:0,他引:2
手性磷酸是2004年报道的一类具有新型结构的强酸性Bronsted酸催化剂,近几年来的研究取得了很大的进展,已经成为有机小分子催化剂的一个重要分支。手性磷酸在催化一系列亚胺的加成和还原反应比如Mannich、亚胺的氢转移、亚胺的膦酰化、Pictet-Spengler、 Strecker、aza-Diels-Alder、 Friedel-Craft和α-重氮酯的烷基化等反应时都表现出了非常好的催化活性和立体选择性。本文主要综述了手性磷酸催化剂应用于亚胺相关反应的研究进展。 相似文献
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温和条件下,苄胺与手性合成子5-(L)-孟氧基3-溴-2(5)呋喃酮通过串联的不对称迈克尔加成/分子内消除反应合成了一种新手性化合物:5-L-孟氧基-4-苄胺基丁烯内酯。产物经过IR、1H-NMR、MS谱学表征,并经X-ray单晶衍射测定了其结构。新化合物属于正交晶系,P212121空间群,a=5.2945(4),b=14.2829(10),c=26.0769(18),Mr=343.45,Z=4,V=1972.0(2)3,Dc=1.157g/cm3,μ(MoKα)=0.076mm-1,F(000)=744,R=0.0387,wR=0.0880。 相似文献