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| 1 | IgD class switch recombination is not controlled through the immunoglobulin heavy chain 3′ regulatory region super-enhancer显示文摘In secondary lymphoid organs,mature B cells express membrane immunoglobulin(Ig)of M and D isotypes(IgM and IgD,respectively)of the same specificity through alternative splicing of a pre-mRNA encompassing the VDJ variable region and Cμand Cδheavy chain constant exons.1 After encountering antigen,B cells undergo class switch recombination(CSR)by which the Cμgene is substituted with Cγ,Cεor Cα,thereby generating IgG,IgE and IgA antibodies of the same antigenic specificity but with new effector functions.CSR requires the DNA-editing enzyme activation-induced deaminase(AID). | Hussein Issaoui Nour Ghazzaui Alexis Saintamand Yves Denizot François Boyer | 2017 | Cellular & Molecular Immunology2017，14，10： | 6 |
| 2 | Negishi Coupling for Highly Selective Syntheses of Allenes via Ligand Effect and Mechanistic Study via SAESI-MS/MS显示文摘β-H elimination is an intrinsic problem in transition metal-catalyzed reactions.We describe herein an interesting ligand effect for Et2Zn acting as either ethyl provider or H provider,respectively:by applying SPhos or Gorlos-Phos as the ligand,β-H elimination has been successfully controlled in the corresponding Negishi coupling reaction affording different poly-substituted allenes in good yields and excellent selectivities.SAESI-MS (Solvent Assisted Electrospray Ionization Mass Spectrometry) has been applied to successfully capture the highly reactive organometallic intermediates,which show the different coordination behaviors of Pd with SPhos or Gorlos-Phos as the ligand in the catalytic cycle.In addition,the different reactivities of Int 1 and Int 2 towards the formation of the final allene products have been demonstrated via SAESI-MS/MS experiments.These MS studies visualized the whole catalytic cycle for the Negishi coupling reaction while nicely explain the observed reactivity and selectivity. | Yangguangyan Zheng Bukeyan Miao Anni Qin Junzhe Xiao Qi Liu Gen Li Li Zhang Fang Zhang Yinlong Guo Shengming Ma | 2019 | Chinese Journal of Chemistry2019，37，10： | 5 |
| 3 | Dysoanthraquinone and 2-demethyldysoanthraquinone from Dysosma majoense显示文摘Two new anthraquinones,dysoanthraquinone and 2-demethyldysoanthraquinone,wereseparated from Dysosma majoense.Both compounds contain methylendioxy at 6—C,7—C.It isvery interesting in terms of biogenetic pathway that they may have been transformed from aryltetralinlignans by means of oxidative cleavage followed by ring closure. | YIN Meng-Long CHEN Zhong-Liang Shanghai Institute of Materia Medica,Academia Sinica,ShanghaiGU Ze-Sheng XIE Yu-Xiang Drug Control Station of Cengong County,Guizhou Province | 1989 | Acta Chimica Sinica English Edition1989，7，5： | 4 |
| 4 | Low temperature sintering behavior of La-Co substituted M-type strontium hexaferrites for use in microwave LTCC technology显示文摘The La-Co substituted Sr_(1–x)La_xFe_(12–x)Co_xO_(19)(x=0–0.5) ferrites with appropriate Bi_2O_3 additive were prepared by conventional sintering method and microwave sintering method at low sintering temperatures compatible with LTCC(low temperature co-fired ceramics) systems, and their sintering behavior was chiefly investigated, including the crystal structure, saturation magnetization Ms, magnetic anisotropy field H a, intrinsic coercivity H ci, and Curie temperature T C. Experiment results clearly showed that the pure M-type crystal phase was successfully obtained when the La-Co substitution amount x did not exceed 0.3. However, the single M-type phase structure transformed to multiphase structure with further increased x, where the M-type phase coexisted with the non-magnetic phase such as α-Fe_2O_3 phase, La_2O_3 phase, and La CoO_3 phase. Appropriate La-Co substitution improved the Ms(>62 emu/g), Ha(>1400 k A/m), and Hci(>320 k A/m) for the ferrites with x varying from 0.1 to 0.3, but the T C decreased with increasing substitution amount. Moreover, the microwave sintered ferrites could provide larger H ci and similar Ms compared with the conventional sintered ferrites. | 黄太星 彭龙 李乐中 王瑞 胡云 涂小强 | 2016 | Journal of Rare Earths2016，34，2： | 4 |
| 5 | Highly Selective Nucleophilic 4-Aryl-2,3-allenylation of Malonates显示文摘of main observation and conclusion Allenes are a class of very important compounds and the development of straightforward,efficient,and highly enantioselective synthetic strategies for allenes have attracted extensive interests.Along this line,it is well known that aryl-substituted allenes may be readily racemized,thus,difficult to prepare in high ee.Herein,an efficient palladium-catalyzed nucleophilic allenylation of malonates w ith racemic 4-aryl-2,3-butadienyl carbonates has been developed.The selectivity issue of mono-vs.bis-allenylation with 2-non-substituted malonates has been addressed.By utilizing(R)-(-)-DTBM-SEGPHOS(5,5'-bisldi(3,5,-di-t-butyl-A-methoxyphenyOphosphino)-4,4'-bi-l,3-benzodioxole)as a chiral ligand,various aryl-substituted allenes and bisallenes have been prepared with good to excellent yields with high chemoselectivity and enantioselectivity under mild reaction conditions.Au-catalyzed cycloisomerization and APK(allenic Pauson-Khand)reactions affording optically active mono-and bicyclic products have been demonstrated. | Shihua Song Shengming Ma | 2020 | Chinese Journal of Chemistry2020，38，11： | 4 |
| 6 | Phosphonium and arsonium ylides(?)——ⅩⅦ.A facile synthesis of methyl 2,6-bisperfluoroalkylbenzoates via acyclic precursors显示文摘The title compounds 6a—6f were prepared with high yield via intramolecular Wittigreaction of methyl 3-perfluoroalkyl-6-perfluoroacyl-2-triphenylphosphoranylidenehex-3,5-dienoates(5a—5i)which were obtained from the reaciton of 3-perfluoroacylprop-2-enylidenetriphenylphos-phoranes(3a—3c)with methyl perfluoroalkynoates(4a—4c). | DING,Wei-Yu CAO,Wei-Guo XU,Zhen-Rong SHI,Zhi-Jian YAO,Yuan Department of Chemistry,Shanghai University of Science and Technology,Shanghai 201800 For part XVI of the series,see J.Chem.Soc.,Perkin Trans.1,1369(1991). | 1993 | Chinese Journal of Chemistry1993，11，1： | 3 |
| 7 | Novel synthetic method for ketones from substituted benzimidazolium salts and Grignard reagents显示文摘A new synthetic method of ketones from substituted benzimidazolium salts and Grignard reagents is reported. The influences of the various Grignard reagents on the yield of ketones and the mechanism are discussed. | 史真 顾焕 | 1996 | Science China Chemistry1996，39，6： | 3 |
| 8 | The ring-substituted phthalo-cyanines and its metal complexes:Crystal structure of 1,4,8,11,15,18,22,25-octa-butoxyphthalocyani- natocopper(Ⅱ)显示文摘Crystal structure of 1, 4, 8, 11, 15, 18, 22, 25-octa-butoxyphthalocyaninatocopper (Ⅱ) (1) was determined by X-ray diffraction methods. The crystal system is mono-clinic, space group is P21/c, Z = 4, a = 1.3741(1) nm, b = 2.6737(1) nm, c = 1.6690(1) nm, β=101.278(1)°. The steric congestion between the neighbouring butoxyl groups causes the distortion of the ring core of phthalocyanine (Pc) into a saddle shape conformation. In the crystal structure, molecules stack along a axis forming one-dimensional packing structure and there are two molecular overlap types which appear in turn with different distances between molecules, overlap area and angle. | CAI Jinwan, WANG Jundong, HUANG Jinling & CHEN NaishengInstitute of Research on Functional Materials, Department of Chemistry, Fuzhou University, Fuzhou 350002, China State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Struct | 2002 | Chinese Science Bulletin2002，47，8： | 3 |
| 9 | SYNTHESIS OF BENZOINS BY DYE PHOTOSENSITIZATION显示文摘Using heavy-atom-containing xanthene dyes,benzoins can be quanti-tatively prepared by photosensitized reduction from benzils with triethyla-mine.It is an important supplement to'benzoin condensation',asp.for thosebenzoins with electron-donating substituents. | Zhan Gong ZHAO Tao SHEN institute of Photographic Chemistry,Academia Sinica,Beijing 100012,China | 1990 | Chinese Chemical Letters1990，1，1： | 3 |
| 10 | Highly Stereoselective Direct Construction of Diaryl-Substituted Cyclobutanes显示文摘A copper catalyzed stereoselective[2+2]cyclization has been developed,providing a concise protocol to the direct construction of diaryl-substituted cyclobutanes in up to 99%yield with up to>95/5 dr.Meanwhile,the enantioselective version of this reaction has also been achieved,leading to a series of optically active diaryl-substituted cyclobutanes with up to 94%ee. | Xiang-Yang Song Liu-Peng Zhao Lijia Wang Yong Tang | 2020 | Chinese Journal of Chemistry2020，38，3： | 2 |
| 11 | Synthesis of per(poly)fluoroalkyl substituted alkenes and alkynes——Utilizing potassium fluoride supported on alumina as a denydrohalogenating agent显示文摘Potassium fluoride on alumina was proved to be an efficient dehydrohalogenating agent for the synthesis of per(poly)fluoroalkyl substituted alkenes and alkynes. The reaction was simple, mild and the yields ranged from good to excellent. | CHEN, Jian HU, Chang-MingShanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, China | 1994 | Chinese Journal of Chemistry1994，12，5： | 2 |
| 12 | Relationship between acute toxicity to aquatic organism of substituted aromatic compounds and their molecular orbital energy显示文摘Quantitative structure-activity relationships (QSARs) are frequently used to study thequantitative relationship between the toxicities and the molecular descriptors of analogue or-ganic compounds. Deliberate QSAR equations can be used to estimate the bioactivities | 黄庆国 赵元慧 张爱茜 王连生 | 1995 | Chinese Science Bulletin1995，40，7： | 2 |
| 13 | Synthesis and Properties of CF3(OCF3)CH-Substituted Arenes and Alkenes显示文摘A silver-mediated oxidative trifluoromethylation of easily accessibleαα-trifluoromethyl alcohols with TMSCF3 was developed to access novel CF3(OCF3)CH-containing compounds.Deprotonation of CF3(OCF3)CH-substituted arenes afforded synthetically useful CF3O-substituted gem-difluoroalkenes.Furthermore,evaluation of the lipophilicities(log P)indicated that CH(OCF3)CF3 is more lipophilic than the common fluorinated motifs such as CF3,OCF3,and SCF3,thus rendering the CH(OCF3)CF3 motif appealing in drug discovery. | Wen-Qi Xu Xiu-Hua Xu Feng-Ling Qing | 2020 | Chinese Journal of Chemistry2020，38，8： | 2 |
| 14 | NEW HETEROCYCLIC SYSTEM SYNTHESIS H THE REACTION OF 2,3-DIHYDRO-1,5-BENZOTHIAZEPINES WITH DICHLOROCARBENE显示文摘The reaction of two series of 2,3-dihydro-1,5-henzothiazepines Ⅰ with dichloro-carbene,gave azirino[2,1-d][1,5]benzothiazepines Ⅷ,azirino[2,1-e][1,6]benzothiazocines Ⅸ,pyrrolo[2,1-b][1,3]benzothiazoles Ⅹ,substituted-cyclopropanes Ⅺ and 2H-1,4-benzothiazin-2-onesⅫ.The structures of these products were confirmed by the analytical and spectral data.CompoundⅧ and Ⅸ are two new ring systems. | Ruo Xi LAN Sheng JIN Department of Chemistry,Peking University,Beijing 100871Zheng Ming LI Elemento-Organic Chemistry Laboratory,Nankai University,Tianjing 300071 | 1992 | Chinese Chemical Letters1992，3，1： | 2 |
| 15 | SYNTHESIS,CHARACTERIZATION AND OPTICAL PROPERTIES OF THE COPOLYMERS OF C_(60) AND 1-PHENYL-1-PROPYNE显示文摘While WCl6-Ph4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (Mw up to 410×103) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are carried out in the presence of C60 using the W catalyst under the same conditions.The polymers are soluble in common organic solvents such as THF, chloroform, and toluene. Molecularstructures of the polymers are characterized by FT-IR, UV, NMR, GPC and XRD, and it is found that C60 iscopolymerized with PP. Thus C60 plays the dual roles of comonomer and cocatalyst in the polymerizationreaction. C60 contents of the copolymers can be easily changed by varying the C60 amounts in the feedmixtures. The copolymers effectively limit strong 532 nm laser pulses, whose limiting performance issuperior to that of parent C60. | 唐本忠 | 1999 | Chinese Journal of Polymer Science1999，17，4： | 2 |
| 16 | Relative reactivities of bromine-substituted substrates toward bromophilic attack by a carbanion显示文摘Halophilic attack on carbon-halogen bond by nucleophiles has recently become a sub-ject of interest and intensive study.A wide variety of substrates and nucleophiles has beenexamined.But no quantitative measurements on the reactivities of substrates have ever beenreported.The present work is a first attempt to evaluate the relative reactivities of perfluoro-bromoalkanes(R-Br)and some bromo organic compounds(R-Br)by intermolecular compe-tition kinetics.A large excess of Cl3CCF2CF2Cl(1),a chlorine-containing substrate withconvenient reactivity toward halophilic attack,and R-Br is used to compete for a small amountof the enolate anion of mesityl isopropyl ketone(E-)in dimethyl formamide(DMF)at 20℃in their reactions to form α-chloroisopropyl mesityl ketone(A)and α-bromoisopropylmesityl ketone(B)as products(eq 1) | LI,Xing-Ya JIANG,Xi-Kui ZHANG,Xiao-Jun Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,345 Lingling Lu,Shanghai 200032 | 1992 | Chinese Journal of Chemistry1992，10，2： | 2 |
| 17 | STUDY ON THE SYNTHESIS OF A NEW TYPE OF PHOSPHORUS HETEROCYCLIC COMPOUNDS-PYRAZOLO[3,4-d]-1,3,2-DIAZAPHOSPHORIN-6-ONE显示文摘1-substituted-5-benzoylamino-4-pyrazolecarboxamides(2)wereprepared by the reaction of 1-substituted pyrazolo[3,4-d]-oxazinone(1)with amines in benzene.The compound 2 was refluxed with excess LiAlH4in a mixture of THF and ether,one of the two carbamoyl groups in themolecule 2 was reduced selectively.As the results,1-substituted-5-benzylamino-4-pyrazolecarboxamides(3)were obtained.Compounds 3reacted with Cl2PPh-X,or P(NET2)3,producing the title compounds(4).The conditions of the reactions were studied. | Ru Yu CHEN Jian Wu WANG Institute of Elemento-Organic Chemistry,Nankai University,Tianjin 300071,China | 1990 | Chinese Chemical Letters1990，1，1： | 2 |
| 18 | One-Pot Synthesis of Substituted Cyclohexanes from Condensation of Aldehyde and Methylketone显示文摘Three asymmetrically substituted cyclohexanes were prepared from one-pot reactions of aldehydes and methylketones, and the products were characterized by single crystal structure analysis, NMR spectroscopy and microanalysis. | Yin, YG Cheung, KK Wong, WT | 1998 | Chinese Chemical Letters1998，9，4： | 1 |
| 19 | POLAR SUBSTITUENT EFFECTS OF ORGANOPHOSPHORUS ESTERS IN STRUCTURE-REACTIVITY STUDIES显示文摘In order to study the polar substituent effect almost with no steric effect in organophosphoruschemistry,a series of 4-substituted-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane 1-oxides(1)and p-substitutedphenylphosphonates(2)and corresponding mono hexyl esters(3)as model were synthesized.31P-NMR chemicalshifts of compounds(1)in methanol and deuterioacetone were determined.The Δδ values reflect 4-sbstituent po-lar effect.The 31P-NMR of compounds(2)and(3)and the pKa of compounds(3)were also measured.Theresults showed that the trend of polar effects of substituents in both carboxylic and organophosphates chemistryare similar,and the change of polar effects in variation with the alkyl groups is not significant. | Wen Xiang HU Cheng Ye YUAN Shu Sen LI Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,345 Lingling Lu,Shanghai 200032 Institute of Pharmacology and Toxicology,Academy of Military Medical Sciences,Beijing 100850. | 1992 | Chinese Chemical Letters1992，3，8： | 1 |
| 20 | OXIDATION OF ALKYLBENZENES CATALYZED BY IRON( Ⅱ,Ⅲ)-1,10-PHENANTHROLINE AND 2, 2'-BIPYRIDINE COMPLEXES显示文摘Oxidation of alkybenzenes PhCH2R(R=H, CH3, C2H5 and n-C3H7) under 1 atm. of O2 or air catalyzed by iron(Ⅱ, Ⅲ)-2,2’-bipyridine and 1,10-phenanthroline complexes, affords the aryl-substituted ketones and alcohols with the conversion of 15.00%~34.58% containing of 97.60%~99.80% ketones and alcohols. The turnover numbers of these catalysts are over 3500 mol-cat. -1for 3.5 h. | Zi Qiang LEI~* Yun Pu WANG Department of Chemistry, Northwest Normal University, Lanzhou 730070 | 1993 | Chinese Chemical Letters1993，4，1： | 1 |
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