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1.
Francoise Sauriol Dr. Elizabeth Wong Angela M. H. Leung Irja Elliott Donaghue Michael C. Baird Prof. Tebikie Wondimagegn Dr. Tom Ziegler Prof. 《Angewandte Chemie (International ed. in English)》2009,48(18):3342-3345
Caught in the act : An alkyl alkene ZrIV complex (see picture; Cp=C5H5) has been synthesized and characterized for the first time. The alkene bonding mode is highly asymmetric, and C2 is quite carbocationic. There is also evidence for rotation about the C1? C2 bond. This extremely unusual complex provides an exemplar of previously unknown intermediates in Ziegler–Natta and carbocationic polymerization reactions of alkenes.
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Ken‐ichi Shimizu Dr. Ryosuke Sato Atsushi Satsuma Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(22):3982-3986
Let's drink to that! Two alcohols (one primary and one secondary) can be coupled in an atom‐efficient process by a hydrogen‐autotransfer catalytic system in the form of silver subnanoclusters supported on γ‐Al2O3. The recyclable heterogeneous catalyst promoted the one‐pot C? C cross‐coupling in the presence of a catalytic amount of the weak base Cs2CO3 (see reaction mechanism).
3.
Nicolas Dietl Marianne Engeser Dr. Helmut Schwarz Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(26):4861-4863
No need for a metal : A combination of mass spectrometry and computational studies (density functional theory and coupled‐cluster methods) shows that [P4O10].+ is the first polynuclear nonmetal oxide cation that is capable of activating the C? H bond of methane at room temperature (see picture). This process represents a further example in the reactivity of oxygen‐centered radicals.
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Gunther Steinfeld Dr. Vasile Lozan Dr. Hans‐Jörg Krüger Prof. Dr. Berthold Kersting Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(11):1954-1957
Stuck on sulfur : The first transition‐metal complexes with S? Br units are surprisingly stable. Solid 3 is stable for at least six months and under vacuum solid 2 does not lose Br2. The formation of the first structurally characterized transition‐metal arenesulfenyl bromide complex 3 occurs with a change of the spin ground state from S=2 to S=0.
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Céline Chizallet Dr. Pascal Raybaud Dr. 《Angewandte Chemie (International ed. in English)》2009,48(16):2891-2893
Amorphization tunes acidity : Pseudo‐bridging silanols, suggested as versatile Brønsted acid groups by molecular modeling studies, are obtained by shifted hydrolysis of Si? O? Al bridges formed by the thermal treatment of silica deposited on γ‐Al2O3 (100), and appear under given pretreatment conditions. Demixing of part of the silica from the aluminosilicate phase is predicted upon excess water adsorption.
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Hai Zhou Yun‐He Xu Wan‐Jun Chung Teck‐Peng Loh Prof. 《Angewandte Chemie (International ed. in English)》2009,48(29):5355-5357
It does get in! A fluoride‐assisted direct cross‐coupling of cyclic enamides with trialkoxy aryl silanes by a palladium‐catalyzed C? H activation leads to a wide range of enamides in yields of up to 95 %.
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Jasmin Mecinović Refaat B. Hamed Christopher J. Schofield Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(15):2796-2800
Three of a kind : Vicinal tricarbonyl compounds undergo C? C cleavage mediated by ferric ions (see scheme). The observed cleavage of ninhydrin and dehydroascorbic acid has relevance for amino acid detection and the metabolism of vitamin C.
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Amitabha Mitra Dr. Joseph P. Wojcik Daniel Lecoanet Thomas Müller Prof. Dr. Robert West Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(22):4069-4072
SiSe matters : Diselenadisiletane 2 , formed from direct reaction of a racemic silylene 1 with elemental selenium, gives the first bis(silaselenone) upon hydrolysis with water ( 3 ; see picture, C gray, H white, N blue, O red, Se purple, Si green; d(Si?Se)=215 pm). The reaction is stereoconvergent: only racemic forms of 3 are obtained from a mixture of racemic and meso forms of 2 .
10.
Shin Aoki Prof. Yumiko Tomiyama Yoshiyuki Kageyama Dr. Yasuyuki Yamada Dr. Motoo Shiro Dr. Eiichi Kimura Prof. 《化学:亚洲杂志》2009,4(4):561-573
Conditional cleavage : Photochemical S? N bond cleavage of the Zn2+ complex of N‐dansylcyclen (ZnL2) in aqueous solution was investigated. Moreover, photolysis of ZnL2 (see scheme) facilitated photoreversion of cis,syn‐thymine photodimer (T[c,s]T).
11.
StephenP. Thomas VarinderK. Aggarwal 《Angewandte Chemie (International ed. in English)》2009,48(11):1896-1898
A breakthrough in the asymmetric hydroboration of notoriously difficult 1,1‐disubstituted alkenes using a new family of highly effective hydroboration reagents is described (see scheme). The intermediate boranes can be oxidized to alcohols or used in Suzuki–Miyaura cross‐coupling reactions.
12.
Yi‐Zhou Li Bi‐Jie Li Xing‐Yu Lu Song Lin Zhang‐Jie Shi Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(21):3817-3820
Hooking up : FeCl2 catalyzes the efficient cross dehydrogenative arylation of substrates having benzylic C? H bonds (see scheme). High regioselectivity was observed during the cross‐coupling between compounds containing aromatic C(sp2)? H bonds and benzylic C(sp3)? H bonds. This process is proposed to proceed by single‐electron‐transfer oxidation and Friedel–Crafts alkylation.
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Anthony S. R. Chesman David R. Turner Dr. Glen B. Deacon Prof. Stuart R. Batten Assoc. Prof. 《化学:亚洲杂志》2009,4(5):761-769
Additional cyclization : Dicyanonitrosomethanide, [C(CN)2(NO)]? undergoes nucleophilic addition and cyclization of 1,2‐diaminoethane and 1,3‐diaminopropane on the nitrile groups to form imidazolinyl and 1,4,5,6‐tetrahydropyrimidinyl groups, respectively. Ethanolamine has lower reactivity and fails to cyclize.
14.
Bijan Nekoueishahraki Dipl.‐Chem. Sankaranarayana Pillai Sarish Dipl.‐Chem. Herbert W. Roesky Prof. Dr. Daniel Stern Carola Schulzke Prof. Dr. Dietmar Stalke Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(25):4517-4520
Bi? O chemistry : A direct regioselective route to bismuth bis(amino)naphthalene compounds, incorporating Bi? O and Bi? C bonds is described, in which an amide precursor is treated with aldehydes, ketones, alkenes, and alkynes, leading to insertion into the Bi? NMe2 bond.
15.
Shangdong Yang Zigang Li Xing Jian Chuan He Prof. 《Angewandte Chemie (International ed. in English)》2009,48(22):3999-4001
Ring leader : PtCl2 catalyzes intramolecular cyclization of o‐isopropyl or o‐benzyl aryl alkynes to give substituted indene derivatives with good yields and high selectivity. This reaction appears to proceed through an sp3 C? H activation and 1,4‐hydrogen migration pathway (see scheme).
16.
Tristram Chivers Prof. Dr. Jari Konu Dr. 《Angewandte Chemie (International ed. in English)》2009,48(17):3025-3027
Chalcogen‐transfer reagents? The bonding in the dicationic rings C2N2E2+ (see picture) differs from that in N‐heterocyclic carbenes and their isovalent p‐block analogues in accommodating a lone pair of electrons with π symmetry, as well as σ symmetry, on the chalcogen center. The labile electrophilic chalcogenium dications (E2+) are potentially versatile chalcogen‐transfer reagents in reactions with a variety of inorganic and organic substrates.
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Sohail A. Shahzad Thomas Wirth Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(14):2588-2591
When one ring is not enough : A new double cyclization of stilbene derivatives results in benzo[b]fluorenes via dihydronaphthalenes. The presence of a selenium electrophile and a Lewis acid are crucial for the formation of the C? C bonds.
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Michael North 《Angewandte Chemie (International ed. in English)》2009,48(23):4104-4105
Hidden talent : Often perceived to be too thermodynamically and kinetically inert to be a useful chemical feedstock, carbon dioxide adds to allenes under exceptionally mild reductive conditions in the presence of a palladium pincer complex to give β,γ‐unsaturated carboxylic acids (see scheme). This transformation is discussed in the context of the requirements for CO2 fixation. DMF=N,N‐dimethylformamide, Tf=trifluoromethanesulfonyl.