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Cover Picture: Unusual Nitrile–Nitrile and Nitrile–Alkyne Coupling of FcCN and FcCCCN (Chem. Eur. J. 11/2014) 下载免费PDF全文
Lisanne Becker Frank Strehler Marcus Korb Dr. Perdita Arndt Dr. Anke Spannenberg Dr. Wolfgang Baumann Prof. Dr. Heinrich Lang Prof. Dr. Uwe Rosenthal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(11):2969-2969
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Gabriele Hierlmeier Peter Coburger Michael Bodensteiner Robert Wolf 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(47):17074-17078
Die Tetrahedrane sind eine bisher nur wenig entwickelte Verbindungsklasse und insbesondere ist mit AsP3 bisher nur ein einziges neutrales, heteroatomares Tetrahedran bekannt. Hier berichten wir über die Synthese eines neutralen, molekularen X2Y2‐Tetraeders (X, Y=p‐Blockelemente), der gleichzeitig das erste Beispiel des seit langem postulierten freien Phosphaalkindimers ist. Di‐tert‐butyldiphosphatetrahedran, (tBuCP)2, lässt sich aus dem Monomer tBuCP in einer nickelkatalysierten Dimerisierungsreaktion unter Verwendung von [(NHC)Ni(CO)3] (NHC=1,3‐Bis(2,4,6‐trimethylphenyl)imidazolin‐2‐yliden (IMes) bzw. 1,3‐Bis(2,6‐diisopropylphenyl)imidazolin‐2‐yliden (IPr)) als Katalysator darstellen. Die Einkristallröntgenstrukturanalyse eines Silber(I)‐komplexes bestätigt die tetraedrische Struktur. Der Einfluss des N‐heterocyclischen Carbenliganden auf die katalytische Reaktion wird diskutiert und auf Basis von synthetischen, kinetischen und quantenmechanischen Untersuchungen wird ein möglicher Bildungsmechanismus vorgestellt. 相似文献
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Metal‐Free CN‐ and NN‐Bond Formation: Synthesis of 1,2,3‐Triazoles from Ketones,N‐Tosylhydrazines,and Amines in One Pot 下载免费PDF全文
Zhengkai Chen Qiangqiang Yan Zhanxiang Liu Prof. Dr. Yuhong Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(52):17635-17639
A novel synthetic approach toward 1,4‐disubstituted 1,2,3‐triazoles by C?N‐ and N?N‐bond formation has been established under transition‐metal‐free conditions. Complete control of the regioselectivity was successfully achieved. Commercially available anilines, ketones, and N‐tosylhydrazine were treated with molecular iodine in one pot to allow the regioselective generation of 1,4‐disubstituted 1,2,3‐triazoles in high yields without the use of azides. 相似文献
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Clemens Taube Kai Schwedtmann Medena Noikham Ekasith Somsook Felix Hennersdorf Robert Wolf Jan J. Weigand 《Angewandte Chemie (International ed. in English)》2020,59(9):3585-3591
[LCRP((PhP)2C2H4)][OTf] ( 4 a,b [OTf]) and [LCiPrP(PPh2)2][OTf] ( 5 b [OTf]) were prepared from the reaction of imidazoliumyl‐substituted dipyrazolylphosphane triflate salts [LCRP(pyr)2][OTf] ( 3 a,b [OTf]; a : R=Me, b =iPr; LCR=1,3‐dialkyl‐4,5‐dimethylimidazol‐2‐yl; pyr=3,5‐dimethylpyrazol‐1‐yl) with the secondary phosphanes PhP(H)C2H4P(H)Ph) and Ph2PH. A stepwise double P?N/P?P bond metathesis to catena‐tetraphosphane‐2,3‐diium triflate salt [(Ph2P)2(LCMeP)2][OTf]2 ( 7 a [OTf]2) is observed when reacting 3 a [OTf] with diphosphane P2Ph4. The coordination ability of 5 b [OTf] was probed with selected coinage metal salts [Cu(CH3CN)4]OTf, AgOTf and AuCl(tht) (tht=tetrahydrothiophene). For AuCl(tht), the helical complex [{(Ph2PPLCiPr)Au}4][OTf]4 ( 9 [OTf]4) was unexpectedly formed as a result of a chloride‐induced P?P bond cleavage. The weakly coordinating triflate anion enables the formation of the expected copper(I) and silver(I) complexes [( 5 b )M(CH3CN)3][OTf]2 (M=Cu, Ag) ( 10 [OTf]2, 11 [OTf]2). 相似文献
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Splitting a Substrate into Three Parts: Gold‐Catalyzed Nitrogenation of Alkynes by CC and CC Bond Cleavage 下载免费PDF全文
Chong Qin Dr. Yijin Su Tao Shen Prof. Xiaodong Shi Prof. Ning Jiao 《Angewandte Chemie (International ed. in English)》2016,55(1):350-354
A gold‐catalyzed nitrogenation of alkynes for the synthesis of carbamides and amino tetrazoles through C? C and C?C bond cleavages is described. A diverse set of functionalized carbamide and amino tetrazole derivatives were selectively constructed under mild conditions. The chemoselectivity can be easily switched by the selection of the acid additives. The reaction is characterized by its broad substrate scope, direct construction of high value products, easy operation under air, and mild conditions at room temperature. This chemistry provides a way to transform alkynes by splitting the substrate into three parts. 相似文献
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The R-C≡N…pyrrole (R=H, CH3, CH2F, CHF2, CF3, NH2, BH2, OH, F, CH2Cl, CHCl2, CCl3, Li, Na) complexes were considered as the simple sample for measure of hydrogen bonding strength. Density functional theory B3LYP/6-311 G^** level was applied to the optimization of geometries of complexes and monomers. Measure of hydrogen bonding strength based on geometrical and topological parameters, which were derived from the AIM theory, was analyzed. Additionally, natural bond orbital (NBO) analysis and frequency calculations were performed.From the computation results it was found that the electronic density at N-H bond critical points was also strictly correlated with the hydrogen bonding strength. 相似文献
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Rhodium(III)‐Catalyzed CC and CO Coupling of Quinoline N‐Oxides with Alkynes: Combination of CH Activation with O‐Atom Transfer 下载免费PDF全文
Xueyun Zhang Zisong Qi Prof. Xingwei Li 《Angewandte Chemie (International ed. in English)》2014,53(40):10794-10798
[Cp*RhIII]‐catalyzed C? H activation of arenes assisted by an oxidizing N? O or N? N directing group has allowed the construction of a number of hetercycles. In contrast, a polar N? O bond is well‐known to undergo O‐atom transfer (OAT) to alkynes. Despite the liability of N? O bonds in both C? H activation and OAT, these two important areas evolved separately. In this report, [Cp*RhIII] catalysts integrate both areas in an efficient redox‐neutral coupling of quinoline N‐oxides with alkynes to afford α‐(8‐quinolyl)acetophenones. In this process the N? O bond acts as both a directing group for C? H activation and as an O‐atom donor. 相似文献
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Palladium‐Catalyzed Enantioselective CH Arylation for the Synthesis of P‐Stereogenic Compounds 下载免费PDF全文
Zi‐Qi Lin Wei‐Zhen Wang Shao‐Bai Yan Prof. Dr. Wei‐Liang Duan 《Angewandte Chemie (International ed. in English)》2015,54(21):6265-6269
A palladium‐catalyzed enantioselective C? H arylation of N‐(o‐bromoaryl)‐diarylphosphinic amides is described for the synthesis of phosphorus compounds bearing a P‐stereogenic center. The method provides good enantioselectivities and high yields. The products were readily transformed into P‐chiral biphenyl monophosphine ligands. 相似文献
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Lewis Acid Mediated Tandem Reaction of Propargylic Alcohols to Tetrazoles Involving CO‐ and CC‐Bond Cleavage Reactions and a CN‐Bond Formation 下载免费PDF全文
Dr. Xian‐Rong Song Ya‐Ping Han Yi‐Feng Qiu Zi‐Hang Qiu Xue‐Yuan Liu Prof. Dr. Peng‐Fei Xu Prof. Dr. Yong‐Min Liang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(38):12046-12050
A novel and direct synthesis of 1‐aryl‐5‐arylvinyl‐tetrazoles from easily prepared propargylic alcohols and TMSN3 is developed in the presence of TMSCl under mild conditions (TMS=trimethylsilyl). The process involves an allenylazide intermediate, followed by a C?C‐bond cleavage and C?N‐bond formation to afford the desired products. Moreover, this method offers a good functional‐group applicability and can be scaled‐up to grams (yield up to 85 %). 相似文献