检索结果-南通市图书馆

An Efficient Synthetic Method of 11,12-Dihydroxyl Eudesmanolide Sesquiterpenoid from a -Santonin

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2001年第1期12卷 21-24页

作者： Wu Jiong XIA De Run LI yong qiang tu Ao Cheng CAO Department of Chemistry National Laboratory of Applied Organic ChemistryLanzhou UniversityLanzhou 730000 Institute of Plant Protection Chinese Academy of Agricultural SciencesBeijing 100094

A short and efficient procedure for introduction of tertiary hydroxyl to C-11 of eudesmanolide based on the rearrangement-oxidation of the exocylic double bond has been developed, which is synthetically valuable for a... 详细信息

关键词： Introduction tertiary hydroxyl rearrangement-oxidation

Studies on the Synthesis of Morphinan Alkaloid:Preparation of the Key Allylic Silyl Ether Precursor

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2005年第11期16卷 1445-1447页

作者： Zhen Lei SONG yong qiang tu Shuan Hu GAO Yi Jun JIANG Shu Yu ZHANG State Key Laboratory of Applied Organic Chemistry ＆ Department of Chemistry Lanzhou University Lanzhou 730000

A convergent strategy to the key allylic silyl ether precursor 4 in our synthetic efforts toward morphinan alkaloid is presented. The vital step is the selective 1,2-addition of the organocerium agent of 6 to ketene 5.

关键词： Morphinan alkaloid Weinreb amide cerium chloride synthesis.

Aromatic and olefinic C–H alkenylation by catalysis with spirocyclic NHC Ru(Ⅳ) pincer complex

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2023年第10期66卷 2791-2796页

作者： Heng Cai yong-qiang tu Ka Lu Qi-Long Chen Fu-Min Zhang Xiao-Ming Zhang Yuan-Jiang Pan Zhi-Bo Yan State Key Laboratory of Applied Organic Chemistry&College of Chemistry and Chemical Engineering Lanzhou UniversityLanzhou 730000China School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Jiao Tong UniversityShanghai 200240China Department of Chemistry Zhejiang UniversityHangzhou 310027China

Catalyst innovation lies at the heart of transition-metal-catalyzed reaction development. In this article, we have explored the C(sp2)–H alkenylation activity with novel spirocyclic N-heterocyclic carbene(NHC)-based cyclometalated ruthenium pincer catalyst system, SNRu-X. After screening catalyst and condition, a high valent Ru(Ⅳ) dioxide(X = O_(2)) species has demonstrated superior reactivity in the catalytic alkenylation of aromatic and olefinic C–H bonds with unactivated alkenyl bromides and triflates. This reaction has achieved the easy construction of a wide range of(hetero)aromatic alkenes and dienes, in good to excellent yields with exclusive selectivity. Preliminary mechanistic studies indicate that this reaction may proceed through a single electron transfer(SET) triggered oxidative addition, by doing so, providing valuable complementary to classical alkenylation reactions that are dependent on activated alkenyl precursors.

关键词： transitionmetal catalysis spirocyclic NHC-Ru pincer catalyst C-H alkenylation single electron transfer pathway unactivated alkenyl bromides and triflates

INVESTIGATION OF CHEMICAL CONSTItuENT FROM CELASTRUS ANGULAtuS

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1992年第8期3卷 625-628页

作者： yong qiang tu Department of Chemistry,Lanzhou University,Lanzhou,730000

Three new β-dihydroagarofuran sesquiterpene polyol esters,one alkaloid and two non-alkaloids,were isolated from the MeOH extract of seed oil of Celastrus angulatus. Their structures were elucidated on the basis of UV... 详细信息

关键词： Chen Wang EIMS INVESTIGATION OF CHEMICAL CONSTItuENT FROM CELASTRUS ANGULAtuS

A NEW SESQUITERPENE FROM CELASTRUS ROSTHONIANUS

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1991年第12期2卷 935-936页

作者： yong qiang tu Department of Chemistry, Lanzhou University, Lanzhou, 730000

A new sesquitcrpene was isolated from Celastrus rothornianus, its structure was clucidated mainly on the basis of spectral analysis.

关键词： Office Chen A NEW SESQUITERPENE FROM CELASTRUS ROSTHONIANUS

Synthesis of 6,8,9,12-Tetrahydroxylated Dihydroagarofuran Sesquiterpenoid from α-Santonin

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第12期10卷 999-0,0-0页

作者： Wu Jiong XIA Liang Dong SUN yong qiang tu(Department of Chemistry and National Laboratory of AppliedOrganic Chemistry, Lanzhou University, Lanzhou, 730000) Department of Chemistry Natl. Lab. of Appl. Organ. Chemistry Lanzhou University Lanzhou 730000 China

The tittle compound has been synthesized successfully through the efficient andselective functional transformation of a-santonin. This procedure is the first successful approachdeveloped for synthesis of the dihydroag... 详细信息

关键词： Synthesis dihydroagarofuran sesquiterpenoid polyhydroxylation.

Synthetic Studies of Didemnaketals Analogue-Construction of the Intermediate (3S,5S,6R)-3,7-Dimethyl-5,6,7-trihydroxy-octanal

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2000年第6期11卷 509-510页

作者： Yan Xing JIA Bin WU Ping Zhen WANG yong qiang tu(Department of Chemistry and National Laboratory of Applied Organic Chemistry, Lanzhou University Lanzhou 730000) Department of Chemistry and National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000

An efficient and stereoselective synthetic procedure for (3S,5S,6R)-3,7-dimethyl-5,6,7-trihydroxy-octanal derivative, the intermediate for synthetic of the HIV-active didemnaketals analogue. was developed via a series of reactions from the natural (+)-Pulegone. In this approach, an efficient diastereoselective reaction of the epoxides 8 and 9 with PCC has been accomplished.

关键词： dedemnaketals stereoselective synthesis diastereoselective reaction

Development of unique dianionic Ir(Ⅲ) CCC pincer complexes with a favourable spirocyclic NHC framework

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2020年第12期63卷 1761-1766页

作者： Zhi-Bo Yan Kun-Long Dai Bin-Miao Yang Zi-Hao Li yong-qiang tu Fu-Min Zhang Xiao-Ming Zhang Meng Peng Qi-Long Chen Ze-Ran Jing State Key Laboratory of Applied Organic Chemistry&College of Chemistry and Chemical Engineering Lanzhou UniversityLanzhou 730000China School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Jiao Tong UniversityShanghai 200240China

A new type of dianionic Ir(Ⅲ) CCC pincer complexes(SNHC-Ir, 1a–1c) is successfully designed and synthesized by developing a one-step methodology, which involves an initial coordination of Ir(I) with the NHC and subsequent metallation of double sp2C–H bonds. This method is considerably useful over those reported by using strong coordination ligand or carbonic anion exchange,and would provide an alternative efficient template of organometallics synthesis. Experimental and density functional theory(DFT) calculation results indicate that the spirocyclic framework is a favourable factor for the facile formation and stabilization of these complexes. Primary investigation shows that chloride 1b can well catalyze homo and hetero addition of styrene derivatives and remote olefin isomerization, which represents the first catalytic application of the dianionic CCC pincer complexes.

关键词： spirocyclic NHC framework dianionic CCC pincer complexes iridium-catalyzed C–H activation

A NEW ALKALOID FROM CELASTRUS ANGULAtuS

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1993年第3期4卷 219-220页

作者： yong qiang tu Yu Xin CUI yong Xiang MA Department of Chemistry,Lanzhou University,Lanzhou,730000

A new β-dihydroagarofuran alkaloid Ⅰ was isolated from Celastrus *** structure was established on the basis of 1D and 2D NMR analysis,and x-ray diffraction.

关键词： A NEW ALKALOID FROM CELASTRUS ANGULAtuS