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Jiawang Liu Carolin Schneider Ji Yang Zhihong Wei Haijun Jiao Robert Franke Ralf Jackstell Matthias Beller 《Angewandte Chemie (International ed. in English)》2021,60(1):371-379
A chemo‐, regio‐, and stereoselective mono‐hydroamidation of (un)symmetrical 1,3‐diynes is described. Key for the success of this novel transformation is the utilization of an advanced palladium catalyst system with the specific ligand Neolephos. The synthetic value of this general approach to synthetically useful α‐alkynyl‐α, β‐unsaturated amides is showcased by diversification of several structurally complex molecules and marketed drugs. Control experiments and density‐functional theory (M06L‐SMD) computations also suggest the crucial role of the substrate in controlling the regioselectivity of unsymmetrical 1,3‐diynes. 相似文献
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A Strategy for the Preparation of Thioantimonates Based on the Concept of Weak Acids and Corresponding Strong Bases
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Carolin Anderer Natalie Delwa de Alarcón Prof. Dr. Christian Näther Prof. Dr. Wolfgang Bensch 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(51):16953-16959
By following a new synthetic approach, which is based on the in situ formation of a basic medium by the reaction between the strong base Sb(V)S43? and the weak acid H2O, it was possible to prepare three layered thioantimonate(III) compounds of composition [TM(2,2′‐bipyridine)3][Sb6S10] (TM=Ni, Fe) and [Ni(4,4′‐dimethyl‐2,2′‐bipyridine)3][Sb6S10] under hydrothermal conditions featuring two different thioantimonate(III) network topologies. The antimony source, Na3SbS4 ? 9 H2O, undergoes several decomposition reactions and produces the SbIIIS3 species, which condenses to generate the layered anion. The application of transition‐metal complexes avoids crystallization of dense phases. The reactions are very fast compared to conventional hydrothermal/solvothermal syntheses and are much less sensitive to changes of the reaction parameters. 相似文献
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Matthias Brendel Carolin Braun Dr. Frank Rominger Prof. Dr. Peter Hofmann 《Angewandte Chemie (International ed. in English)》2014,53(33):8741-8745
For a long time d10‐ML2 fragments have been known for their potential to activate unreactive bonds by oxidative addition. In the development of more active species, two approaches have proven successful: the use of strong σ‐donating ligands leading to electron‐rich metal centers and the employment of chelating ligands resulting in a bent coordination geometry. Combining these two strategies, we synthesized bis‐NHC chelate complexes of nickel(0) and platinum(0). Bis(1,5‐cyclooctadiene)nickel(0) and ‐platinum(0) react with bisimidazolium salts, deprotonated in situ at room temperature, to yield tetrahedral or trigonal‐planar bis‐NHC chelate olefin complexes. The synthesis and characterization of these complexes as well as a first example of C? C bond activation with these systems are reported. Due to the enforced cis arrangement of two NHCs, these compounds should open interesting perspectives for bond‐activation chemistry and catalysis. 相似文献
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Jiawang Liu Ji Yang Carolin Schneider Robert Franke Ralf Jackstell Matthias Beller 《Angewandte Chemie (International ed. in English)》2020,59(23):9032-9040
For the first time, the monoalkoxycarbonylation of easily available 1,3‐diynes to give synthetically useful conjugated enynes has been realized. Key to success was the design and utilization of the new ligand 2,2′‐bis(tert‐butyl(pyridin‐2‐yl)phosphanyl)‐1,1′‐binaphthalene (Neolephos), which permits the palladium‐catalyzed selective carbonylation under mild conditions, providing a general preparation of functionalized 1,3‐enynes in good‐to‐high yields with excellent chemoselectivities. Synthetic applications that showcase the possibilities of this novel methodology include an efficient one‐pot synthesis of 4‐aryl‐4H‐pyrans as well as the rapid construction of various heterocyclic, bicyclic, and polycyclic compounds. 相似文献
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[reaction: see text] Enantioselective Ir-catalyzed intramolecular allylic aminations and etherifications are described. Up to 97% ee was achieved using catalysts prepared by in situ activation of mixtures of phosphorus amidites and [Ir(COD)Cl]2. Sequential aminations of bis-allylic carbonates, involving an inter- followed by an intramolecular reaction, gave trans-N-benzyl-2,5-divinylpyrrolidine and trans-N-benzyl-2,6-divinylpiperidine with > or = 99% ee. New phosphorus amidites as well as improved conditions for intermolecular aminations are reported. 相似文献
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