Journal of The Chemical Society-perkin Transactions 1最新文献_第2页

Asymmetric total synthesis of (–)-podophyllotoxin (-)-鬼臼毒素的不对称全合成

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2010-08-04 DOI: 10.1039/P19960000151

Edward J. Bush, David W. Jones

引用次数: 47

NMR STUDIES OF NONPLANAR PORPHYRINS. PART 1. AXIAL LIGAND ORIENTATIONS IN HIGHLY NONPLANAR PORPHYRINS 非平面卟啉的核磁共振研究。第1部分。高度非平面卟啉的轴向配体取向

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2010-08-03 DOI: 10.1039/A603412H

C. Medforth, C. Muzzi, K. Shea, Kevin M Smith, R. J. Abraham, S. Jia, J. Shelnutt

{"title":"NMR STUDIES OF NONPLANAR PORPHYRINS. PART 1. AXIAL LIGAND ORIENTATIONS IN HIGHLY NONPLANAR PORPHYRINS","authors":"C. Medforth, C. Muzzi, K. Shea, Kevin M Smith, R. J. Abraham, S. Jia, J. Shelnutt","doi":"10.1039/A603412H","DOIUrl":"https://doi.org/10.1039/A603412H","url":null,"abstract":"The ligand orientations in the nonplanar porphyrin complexes \u00001a–e and 2a–e have been investigated using molecular \u0000mechanics calculations and proton NMR spectroscopy. The minimum energy \u0000structures calculated for complexes 1a–e show that the planes of \u0000the axial pyridine or imidazole ligands are orientated approximately \u0000parallel to the CoIII–Nporphyrin bonds, \u0000with the ligand ring planes being perpendicular to each other. For \u0000complexes 2a–e, the planes of the axial ligands in the calculated \u0000minimum energy structures are orientated along the porphyrin \u0000meso carbon axis and the ligand ring planes are \u0000perpendicular to each other. Thus, for both series of complexes the \u0000planes of the axial ligands are orientated parallel to cavities formed \u0000by these very nonplanar porphyrins. Proton NMR studies suggest that \u0000structures similar to those obtained from the molecular mechanics \u0000calculations are retained in solution. In some complexes, hindered \u0000rotation of the axial ligands is also observed. Complexes 1a–e and \u00002a–e are unusual examples of the porphyrin conformation \u0000influencing the orientations of axial ligands and, as such, may be \u0000useful as models for studying ligand orientation effects in relation to \u0000biological systems.","PeriodicalId":17267,"journal":{"name":"Journal of The Chemical Society-perkin Transactions 1","volume":"11 1","pages":"833-838"},"PeriodicalIF":0.0,"publicationDate":"2010-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82398543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

Recent developments in solid-phase organic synthesis 固相有机合成的最新进展

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2010-08-03 DOI: 10.1039/A805801F

Richard C. D. Brown

引用次数: 112

Saturated nitrogen heterocycles 饱和氮杂环

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2010-06-24 DOI: 10.1039/A803231I

A. Mitchinson, A. Nadin

引用次数: 72

Nitro and related compounds 硝基及相关化合物

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2010-06-24 DOI: 10.1039/A801494I

Joseph P. Adams, David S. Box

引用次数: 38

The minor isomers and IR spectrum of [84]fullerene 富勒烯[84]的次要异构体及其红外光谱

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2010-06-24 DOI: 10.1039/A703697C

A. G. Avent, D. Dubois, A. Pénicaud, R. Taylor

引用次数: 52

NMR study of stereoelectronic anomeric and homoanomeric effects on the axial and equatorial CH bonds in 1,3-diazacyclohexanes and 1,5-diazabicyclo[3.2.1]octanes 1,3-二氮杂环己烷和1,5-二氮杂环[3.2.1]辛烷中轴向和平向CH键的立体电子异头和同形异头效应的NMR研究

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2010-06-23 DOI: 10.1039/A705034H

J. Edgar Anderson, J. Cai, Alwyn G. Davies

{"title":"NMR study of stereoelectronic anomeric and homoanomeric effects on the axial and equatorial CH bonds in 1,3-diazacyclohexanes and 1,5-diazabicyclo[3.2.1]octanes","authors":"J. Edgar Anderson, J. Cai, Alwyn G. Davies","doi":"10.1039/A705034H","DOIUrl":"https://doi.org/10.1039/A705034H","url":null,"abstract":"The 1H and 13C NMR spectra of a series of 1,3-di-tert-butyl-1,3-diazacyclohexanes 6, and of 1,5-diazabicyclo[3.2.1]octanes 7, have been investigated in an attempt to find evidence regarding a stereoelectronic interaction of the non-bonding electron pairs on nitrogen or of the C–N bonding electron pairs in the ring, with the axial and equatorial CH bonds of the α- or β-methylene groups. In 6, the orbital carrying the non-bonding electron pair lies antiperiplanar to the axial α-CH bond; a significant nN→σ*CH 3-orbital interaction (the anomeric effect) is sterically possible, and this shows up in the values of δH and of 1JCH. In 7, the doubly-occupied orbital is orientated gauche to both the axial and equatorial α-CH bonds, and no anomeric effect is apparent. In 7 however, in contrast to 6, the stereochemistry is appropriate for a W-plan nN→σ*CH 4-orbital interaction with the equatorial β-CH bond, and comparison of the NMR data of 6 and 7 suggests that such a homoanomeric effect may operate, though it is much weaker than in the analogous 1,3-dioxanes. No evidence could be found for a σCN→σ*CH 3-orbital interaction.","PeriodicalId":17267,"journal":{"name":"Journal of The Chemical Society-perkin Transactions 1","volume":"329 1","pages":"2633-2638"},"PeriodicalIF":0.0,"publicationDate":"2010-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78429612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16

Steric effects in the ionic hydrogenation of aryldi(1-adamantyl)methanols to the corresponding methanes by trifluoroacetic acid and hydrosilanes or sodium borohydride 三氟乙酸与氢硅烷或硼氢化钠离子加氢芳基二(1-金刚烷基)甲醇生成相应甲烷的立体效应

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2010-06-23 DOI: 10.1039/A703648E

J. Lomas, J. Vaissermann

{"title":"Steric effects in the ionic hydrogenation of aryldi(1-adamantyl)methanols to the corresponding methanes by trifluoroacetic acid and hydrosilanes or sodium borohydride","authors":"J. Lomas, J. Vaissermann","doi":"10.1039/A703648E","DOIUrl":"https://doi.org/10.1039/A703648E","url":null,"abstract":"The stereoselectivity of the hydrosilane reduction of substituted di(1-adamantyl)benzyl cations obtained by the protonation of aryldi(1-adamantyl)methanols by trifluoroacetic acid (TFA) in dichloromethane depends on both the hydrosilane and the substituent. Hydrosilanes react with meta-substituted (Me, But or CF3) phenyldi(1-adamantyl)methanols to give variable amounts of the anti and syn hydrocarbons, the variations being rather more pronounced for But (anti:syn = 0.7–23) than for Me (0.32–3.8) and CF3 (0.41–5.4). Almost all o-tolyldiadamantylmethanes give the anti isomer exclusively, as established by NMR spectroscopy and a single crystal X-ray diffraction study of the p-fluoro derivative. In the case of the [2-methyl-5-(tert-butyl)phenyl]diadamantylmethyl cation, however, the stereoselectivity and the rate of hydride transfer depend on the hydrosilane, the most encumbered giving hydrocarbon very slowly. Replacing the hydrosilane by sodium borohydride in these reactions results in untypical stereoselectivities. In particular, small yields of anti-(2-ethylphenyl)diadamantylmethane result from reduction of the corresponding alcohol, whereas normally only products with the syn conformation are obtained from this material.","PeriodicalId":17267,"journal":{"name":"Journal of The Chemical Society-perkin Transactions 1","volume":"79 1","pages":"2589-2596"},"PeriodicalIF":0.0,"publicationDate":"2010-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90313011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

AZULENE-ANNULATED TRICYCLO4.3.1.01,6DECA-2,4,7-TRIENE DERIVATIVES AND THEIR ANIONS. A NOVEL CYCLOHEPTATRIENE-NORCARADIENE VALENCE ISOMERIZATION IN THE AZULENE-ANNULATED TRICYCLO4.3.1.0.1,6DECA-2,4,7-TRIENE RING SYSTEM azulene -环状三环4.3.1.01,6 deca -2,4,7-三烯衍生物及其阴离子。一种新的环庚三烯-去甲二烯在azulene环三环中的价异构化反应

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2010-06-20 DOI: 10.1002/CHIN.199835120

M. Nitta, T. Takayasu

引用次数: 0

Main group organometallics in synthesis 合成中的主要类有机金属

Journal of The Chemical Society-perkin Transactions 1 Pub Date : 2010-06-20 DOI: 10.1039/A706956A

I. Coldham

引用次数: 15