首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 421 毫秒
1.
A simple and effective procedure for the enantioselective synthesis of (R)- and (S)-moprolol was described. The key step was the asymmetric synthesis of enantiopure (R)- and (S)-guaifenesin, which were synthesized from enantioenriched (R)-3-chloro-l,2-propanediol and (S)-epichlorohydrin via kinetics of hydrolysis resolution of racemic epichlorohydrin by chiral Salen-Co^Ⅲ complex. The e.e. values of both the optical compounds were above 98%, and the chemical structures of the target compounds were confirmed by ^1H NMR, ^13C NMR, IR, and MS.  相似文献   

2.
A novel unsymmetrical fluorinated diamine monomer with kink non-coplanar heterocyclic structures, 1,2-dihydro- 2-(4-amino-2-trifluoromethyophenyo)-4-[4-(4-amino-2-trifluoromethyophenoxy)phenyo](2H)phthaoazin-1-oneo was prepared through the nucleophilic substitution reaction of 1-trifluromethyl-2-chloro-5-nitrobenzene with 1,2-dihydro-4-(4- hydroxyphenyl)(2H)phthalazin-l-one in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd-C. A series of new fluorinated polyarnides were synthesized by the phosphorylation polyamidation of the fluorinated diamine with various dicarboxylic acids. The prepared polymers were obtained in quantitative yields with moderately and high inherent viscosities (0.47-0.87 dL/g). They were all amorphous and readily soluble in various polar aprotic solvents such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacctamide (DMAc), pyridine (Py) and m-cresol at room temperature. These fluorinated polyamides have excellent thermal properties. The glass transition temperatures were all above 300℃. The 5% and 10% weight loss temperatures were in the range of 437-466℃ and 482-525℃ in nitrogen atmosphere, respectively.  相似文献   

3.
Two ligands [ortho-C6H4NR2(CH2NH)]2CH2CH2(3: R=Me; 4: R=EO were prepared by the reduction of preligands [ortho-C6H4NR2(CH=N)]zCH2CH2(1: R=Me; 2: R=Et). These ligands reacted with AIMe3 to afford the corresponding dinuclear aluminum complexes {A1Me2[ortho-C6H4NR2(CH2N)]}2CHzCH2(5: R=Me; 6: R=Et). All the compounds were characterized by 1H and UC nuclear magnetic resonance(NMR) spectroscopies and elemental analyses. The catalytic properties of the aluminum complexes towards the ring-opening polymerization of lactones were investi- gated in the presence of benzvl alcohol. All the oolvmerization reactions were proceeded in a controlled manner.  相似文献   

4.
Treatment of N-t-butylbenzenesulfonamide with an excess of BuLi, followed by the reaction with methyl 2-(4-methylphenyl)propanoate, gave the corresponding 2-carboxybenzenesulfonamide, which underwent a sequence of consecutive N-deprotective cyclization process mediated by TMSCI-NaI-MeCN reagent to afford the N-sulfonylimine. Following the bromination and ring expansion, 3-methyl-3-(4-methylphenyl)-2H-benzo[e][1,2]thiazine-l,l,4-trione was obtained. Optical resolution of the racemic benzosultam using (-)-menthoxyacetyl chloride, furnished the optically p.ure (+)- and (-)-3-methyl-3-(4-methylphenyl)-2H- benzo[e][1,2]thiazine-1,1,4-triones, which were fluorinated with FC103 to produce the corresponding chiral N-F agents.  相似文献   

5.
Two calix[4]arene derivatives containing 1,2,3-triazole moiety were synthesized via K2CO3-catalyzed1,3-dipolar cycloaddition reaction between calix[4]arene-based azide and active methylene compounds in good yields.The structures of the two compounds synthesized herein were fully confirmed by 1HNMR,,(13)C NMR,and MS(ESI).The thermal analysis showed that the mass losses of the synthesized compounds 4 and 5 containing 1,2,3-triazole groups are similar to each other.  相似文献   

6.
Two new half-sandwich zirconium(IV) complexes bearing salicylaldimine ligands of the type Cp*Zr[2-tBu-4-R-6-(CH=NiPr)C6H2O]C12[R=H(1), tBu(2)] were prepared by the reaction of Cp*ZrC13 with the corresponding lithium of salicylaldimine ligands 2-tBu-4-R-6-(CH=NiPr)C6H2OLi[R=H(LiLa), tBu(LiLb)]. Com- plexes 1 and 2 were characterized by 1H NMR, BC NMR spectroscopy and elemental analysis. When activated with AliBu3 and Ph3CB(C6F5)4, both complexes 1 and 2 exhibited reasonable catalytic activities for ethylene polymeriza- tion, producing polyethylenes with moderate molecular weight. Complexes 1 and 2 also exhibited reasonable catalyt- ic activities for ethylene copolymerization with 1-hexene, producing poly(ethylene-co-l-hexene)s with moderate molecular weight and reasonable 1-hexene content.  相似文献   

7.
Eleven (S)-(-)-bishydrocarbyl-(l-alkanoylpyrrolidin-2_yl)_methanol derivatives of three types were synthesized from L-proline.asymmtncally selective alkylation products were obtained oy LDA treatment and alkylation using methyl 2-bromoethyl ether, and three types of chiral α-Substituted-γ-butyrolactones were obtained by hydrolyzing the alkylation products, with %e.e. beijing up to 89 percent.  相似文献   

8.
A dinuclear copper(Ⅱ) complex[Cu2(TATP)2(L-Leu)2(CIO4)2]2·2H2Owas synthesized and characterized, where, TATP=1,4,8,9-tetraazatriphenylene, and L-Leu=L-leucinate. The complex was crystallized in the triclinic space group P1, with two independent molecules in a unit cell. Two Cu(Ⅱ) ions in each complex [Cu2(TATP)2(L-Leu)2(CIO4)2] molecule were found to be in different coordination geometries, i.e., Cu2 or Cu4 of a distorted square-pyramidal geometry coordinated with two nitrogens of TATP, the amino nitrogen and one carboxylate oxygen of L-Leu and one oxygen of perchlorate, and Cul or Cu3 with an octahedral geometry coordinated with the above stated similar coordinated atoms, and another carboxylate oxygen of L-Leu coordinating to Cu2 or Cu4. The complex can interact with CT-DNA by an intercalative mode and cleave pBR322 DNA in the presence of ascorbate.  相似文献   

9.
4-(4,6-Dimethylpyrimidin-2-yl)-3-thio-allophanic acid methyl ester was synthesized with mixing 2-amino-4,6- dimethylpyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single crystals suitable for X-ray diffraction measurement were obtained by recrystallization from dimethylformamide at room temperature. The crystal belongs to monoclinic symmetry with space group C2/m, and crystal parameters of a= 1.7537(5) nm, b= 0.6759(2) nm, c=1.1148(3) nm, β=118.557(4)°, V=1.1605(6) nm^3, Z=4, De= 1.375 g/cm^3,μ=0.271 mm^-1, F(000)=504, and 1519 [1〉2σ(I)] observable independent reflections were used for the determination and refmement of the crystal structures with final R1 of 0.0372 and wR2 of 0.0992. The theoretical investigation of the title compound was carried out with DRT-B3LYP/6-311G, HF/6-311G and MP2/6-311G methods, and the atomic net charges and the population were discussed.  相似文献   

10.
Both enantiomers of fluoxetine were synthesized in five steps from ethyl benzoylacetate(1)using microbial-chemical approach with overall yields of 59% and 62% respectively.(S)-Enan-tiomer can be obtained in >99% e.e.by resting cell of baker's yeast and the R form was produced in 81 %e.e.by immobilized Geotrichum sp.G 38.  相似文献   

11.
Reaction of unsaturated (44e (-) skeleton) [PdPt 2(mu-PPh 2) 2(mu-P 2Ph 4)(R F) 4] 4 with Br (-) produces the saturated (48e (-) skeleton) complex [NBu 4][(R F) 2Pt(mu-PPh 2)(mu-Br)Pd(mu-PPh 2)(mu-P 2Ph 4)Pt(R F) 2] 5 without any M-M' bond. Attempts to eliminate Br (-) of 5 with Ag (+) in CH 2Cl 2 as a solvent gives a mixture of [(R F) 2Pt (III)(mu-PPh 2) 2Pt (III)(R F) 2] and some other unidentified products as a consequence of oxidation and partial fragmentation. However, when the reaction of 5 with Ag (+) is carried out in CH 3CN, no oxidation is observed but the elimination of Br (-) and the formation of [(R F) 2(CH 3CN)Pt(mu-PPh 2)Pd(mu-PPh 2)(mu-P 2Ph 4)Pt(R F) 2] 6 (46e (-) skeleton), a complex with a Pt-Pd bond, takes place. It is noteworthy that the reaction of 5 with TlPF 6 in CH 2Cl 2 does not precipitate TlBr but forms the adduct [(R F) 2PtTl(mu-PPh 2)(mu-Br)Pd(mu-PPh 2)(mu-P 2Ph 4)Pt(R F) 2] 7 with a Pt-Tl bond. Likewise, 5 reacts with [AgOClO 3(PPh 3)] in CH 2Cl 2 forming the adduct [AgPdPt 2(mu-Br)(mu-PPh 2) 2(mu-Ph 2P-PPh 2)(R F) 4(PPh 3)] 8, which contains a Pt-Ag bond. Both adducts are unstable in a CH 3CN solution, precipitating TlBr or AgBr and yielding the unsaturated 6. The treatment of [NBu 4] 2[(R F) 2Pt(mu-PPh 2) 2Pd(mu-PPh 2) 2Pt(R F) 2] in CH 3CN with I 2 (1:1 molar ratio) at 233 K yields a mixture of 4 and 6, which after recrystallization from CH 2Cl 2 is totally converted in 4. If the reaction with I 2 is carried out at room temperature, a mixture of the isomers [NBu 4][(R F) 2Pt(mu-PPh 2)(mu-I)Pd(mu-PPh 2)(mu-P 2Ph 4)Pt(R F) 2] 9 and [NBu 4][(R F)(PPh 2R F)Pt(mu-PPh 2)(mu-I)Pd(mu-PPh 2) 2Pt(R F) 2] 10 are obtained. The structures of the complexes have been established on the bases of NMR data, and the X-ray structures of 5- 8 have been studied. The relationship between the different complexes has been studied.  相似文献   

12.
Optically active (1S,3R,4R)-3-[N-(trans-2,5-dialkyl)pyrrolidinyl]methyl-2-azabicyclo-[2.2.1]heptanes were evaluated as catalysts for the enantioselective beta-elimination of meso-epoxides. The (2R,5R)-dimethylpyrrolidinyl-substituted catalyst 4 exhibited exceptionally high enantioselectivity and reactivity, and several substrates were rearranged with enantioselectivities of 98-99% ee. In addition, the use of 4 allowed the first successful, true catalytic rearrangement of the difficult substrates cyclopentene oxide (81%, 96% ee) and (Z)-4-octene oxide (80%, 91% ee).  相似文献   

13.
以新手性拆分试剂R(-)四氢噻唑-2-硫酮-4-羧酸[简称R(-)TTCA]对D,L-氨基酸酯进行手性拆分,分别得到(R)TTCA氨基酸酯盐1a_1f([α]D20=-30.40°~-42.70°)及光学活性氨基酸酯2a-2f,其光学纯度为35.4%~75.8%.由1a_1f在碱存在下分解出2a-2f的对映体3a-3f,光学纯度为39.50%~69.10%.用半经验的量子化学PM3方法研究了氨基的碱性、中间产物铵盐生成热和稳定性.  相似文献   

14.
Coloradocin, a novel macrolide antibiotic from cultures of Actinoplanes coloradoensis1exhibits activity against pathogenic anaerobic and microaerophilic species2. Because itslow toxicity and substantial oral activity3, , as well as its unusual structure5, several 4research groups initiated approaches towards the synthesis of coloradocin6, whichculminated in the synthesis of 18-deoxynargenicin A1 by Kallmerten et al.7. …  相似文献   

15.
非甾体消炎药萘普生不对称合成研究   总被引:8,自引:0,他引:8  
萘普生[(S)-(+)-S-(6'-甲氧基-2'-萘基)丙酸]是一种非常重要的非甾体消炎镇痛药。以(2R,3R)-酒石酸二甲酯为手性辅助剂,2-甲氧基萘经溴代、丙酰化、缩酮化、不对称溴化、水解、立体专一性重排和催化氢转移氢解等反应合成了光学活性萘普生,化学收率44%。制备的萘普生的光学纯度([α]~D^2^5=+63.5ⅲ)符合中华人民共和国药典(1995年版)的要求。  相似文献   

16.
以(2R)-3-[(3S,4R)-1-(叔丁基二甲基硅氧基)乙基]-4-乙酰氧基氮杂环丁-2-酮为母体,2-溴乙(丙)酸酯或2-溴丙酰胺为亲核试剂,通过Reformatsky反应合成了一系列新型的1-β-碳氢霉烯类抗生素中间体——3-{(2R)-2-[(3S,4R)-1-(叔丁基二甲基硅氧基)乙基]氮杂环丁-2-酮-4-基}乙(丙)酸酯(3a~3d)和3-{(2R)-2-[(3S,4R)-1-(叔丁基二甲基硅氧基)乙基]氮杂环丁-2-酮-4-基}-N,N-二取代丙酰胺(3e,3i和3k),其结构经1H NMR和13C NMR表征,其中3a~3e和3i未见文献报道。  相似文献   

17.
摘要 对甲基卞基五羰基锰(CO)5Mn-p-CH2C6H4CH3(4a)或对甲氧基五羰基锰(CO)5Mn-p-CH2C6H4OCH3(4b)与1-2当量R3SiH的C6H6 或C6D6溶液在5oC光解,经色谱纯化后得到中等或高收率硅烷基五羰基锰(CO)5MnSiR3[SiR3 = SiMe2Ph(1b),SiMePh2(1c),SiPh3(1d),SiHPh2(1e),SiEt3(1f),SiMe2tBu(1g),和SiMe2Et(1h)]。光化学反应后,对二甲苯和对甲基苯甲醚副产物分别定量生成,并伴随少量Mn2(CO)10(<1%-6%)。色谱柱的尺寸和温度(室温至- 65 oC)的选择视初始浓度的分解,色谱柱展开期间1的稳定性(过载),以及1与Mn2(CO)10的分离难易而定。去除Mn2(CO)10后的硅烷基五羰基锰3b-3g为浅黄色油状物或无色晶体(只有3h无法分离得到纯净物)。尽管这些化合物对空气敏感对热却相对稳定。  相似文献   

18.
The ligated benzonitriles in the platinum(II) complex [PtCl2(PhCN)2] undergo metal-mediated [2 + 3] cycloaddition with nitrones -ON+(R3)=C(R1)(R2) [R1/R2/R3 = H/Ph/Me, H/p-MeC6H4/Me, H/Ph/CH2Ph] to give delta 4-1,2,4-oxadiazoline complexes, [PtCl2(N=C(Ph)O-N(R3)-C(R1)(R2))2] (2a, 4a, 6a), as a 1:1 mixture of two diastereoisomers, in 60-75% yields, while [PtCl2(MeCN)2] is inactive toward the addition. However, a strong activation of acetonitrile was reached by application of the platinum(IV) complex [PtCl4(MeCN)2] and both [PtCl4(RCN)2] (R = Me, Ph) react smoothly with various nitrones to give [PtCl4(N=C(R)O-N(R3)-C(R1)(R2))2] (1b-6b). The latter were reduced to the corresponding platinum(II) complexes [PtCl2(N=C(R)O-N(R3)-C(R1)(R2))2] (1a-6a) by treatment with PhCH2NHOH, while the reverse reaction, i.e. conversion of 1a-6a to 1b-6b, was achieved by chlorination with Cl2. The diastereoisomers of [PtCl2(N=C(R)O-N(R3)-C(R1)(R2))2] (1a-6a) exhibit different kinetic labilities, and liberation of the delta 4-1,2,4-oxadiazolines by substitution with 1,2-bis(diphenylphosphino)ethane (dppe) in CDCl3 proceeds at different reaction rates to give free N=C(R)O-N(R3)-C(R1)(R2) and [PtCl2(dppe)] in almost quantitative NMR yield. All prepared compounds were characterized by elemental analyses, FAB mass spectrometry, and IR and 1H, 13C(1H), and 195Pt (metal complexes) NMR spectroscopies; X-ray structure determination of the first (delta 4-1,2,4-oxadiazoline)Pt(II) complexes was performed for (S,S)/(R,R)-rac-[PtCl2(N=C(Me)O-N(Me)-C(H)Ph)2] (1a) (a = 9.3562(4), b = 9.8046(3), c = 13.1146(5) A; alpha = 76.155(2), beta = 83.421(2), gamma = 73.285(2) degrees; V = 1117.39(7) A3; triclinic, P1, Z = 2), (R,S)-meso-[PtCl2(N=C(Ph)O-N(Me)-C(H)Ph)2] (2a) (a = 8.9689(9), b = 9.1365(5), c = 10.1846(10) A; alpha = 64.328(6), beta = 72.532(4), gamma = 67.744(6) degrees; V = 686.82(11) A3; triclinic, P1, Z = 1), (S,S)/(R,R)-rac-[PtCl2(N=C(Me)O-N(Me)-C(H)(p-C6H4Me))2] (3a) (a = 11.6378(2), b = 19.0767(7), c = 11.5782(4) A; beta = 111.062(2) degrees; V = 2398.76(13) A3; monoclinic, P2(1)/c, Z = 4), and (S,S)/(R,R)-rac-[PtCl2(N=C(Me)O-N(CH2Ph)-C(H)Ph2] (5a) (a = 10.664(2), b = 10.879(2), c = 14.388(3) A; alpha = 73.11(3), beta = 78.30(3), gamma = 88.88(3) degrees; V = 1562.6(6) A3; triclinic, P1, Z = 2).  相似文献   

19.
以(R)-(+)-α-甲基苄胺为原料,依次经缩合,Diels-Alder反应,还原,Cbz-保护和水解反应,合成了抗丙肝新药HCV NS3/4A蛋白酶拟肽类抑制剂的重要中间体——(1R,3S,4S)-2-苄氧羰基-2-氮杂双环[2.2.1]庚烷-3-羧酸,总收率66%,其结构经1H NMR和ESI-MS确证。  相似文献   

20.
手性催化剂催化下的不对称合成反应是近年来不对称合成研究中受到重视的领域,如在手性催化剂如,在手性冠醚,手性镧配合物、手性硒、手性铑及手性脯氨酸铷盐等催化下,醛、酮与二烃基锌形成手性醇和不对称羟醛缩合反应等,催化下通过Michael加成反应合成手性化合物的方法近年来也有报道,  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号