Results 221 to 230 of about 14,653 (264)
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Organocatalysis by N-Heterocyclic Carbenes
Chemical Reviews, 2007Dieter, Enders +2 more
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Angewandte Chemie International Edition in English, 1997
AbstractThe chemistry of N‐heterocyclic carbenes has long been limited to metal coordination compounds derived from azolium precursors, a development that was started by Öfele and Wanzlick in 1968. Since free carbenes are now available through the work of Arduengo (1991), a renaissance in this little‐recognized area of chemistry has occurred. A leading
Wolfgang A. Herrmann, Christian Köcher
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AbstractThe chemistry of N‐heterocyclic carbenes has long been limited to metal coordination compounds derived from azolium precursors, a development that was started by Öfele and Wanzlick in 1968. Since free carbenes are now available through the work of Arduengo (1991), a renaissance in this little‐recognized area of chemistry has occurred. A leading
Wolfgang A. Herrmann, Christian Köcher
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2016
Abstract This review tries to shed light on the early history of different methods for the generation of N-heterocyclic carbenes (NHCs), i.e., the extrusion of heterocumulenes (decarboxylations) from suitable mesomeric betaines, deprotonations of hetarenium salts, α-eliminations, tautomerizations of mesomeric betaines, and reductive desulfurizations ...
Andreas Schmidt +2 more
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Abstract This review tries to shed light on the early history of different methods for the generation of N-heterocyclic carbenes (NHCs), i.e., the extrusion of heterocumulenes (decarboxylations) from suitable mesomeric betaines, deprotonations of hetarenium salts, α-eliminations, tautomerizations of mesomeric betaines, and reductive desulfurizations ...
Andreas Schmidt +2 more
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Journal of Organometallic Chemistry, 2000
Palladium(0) complexes of N-heterocyclic carbenes (NHC) are easily obtained starting from the free carbene and bis(tri-orthotolylphosphine)palladium(0) by ligand exchange. The complexes [(R)N(H)CC(H)N(R)C ‚„„„„„„„„„” ]2Pd of various 1,3-disubstituted imidazolin-2-ylidenes have been prepared by this method (R mesityl, t-Bu, i-Pr, cyclohexyl).
Volker P.W. Böhm +3 more
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Palladium(0) complexes of N-heterocyclic carbenes (NHC) are easily obtained starting from the free carbene and bis(tri-orthotolylphosphine)palladium(0) by ligand exchange. The complexes [(R)N(H)CC(H)N(R)C ‚„„„„„„„„„” ]2Pd of various 1,3-disubstituted imidazolin-2-ylidenes have been prepared by this method (R mesityl, t-Bu, i-Pr, cyclohexyl).
Volker P.W. Böhm +3 more
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Planar tris-N-heterocyclic carbenes
Chemical Communications, 2013To further explore the coordination chemistry of poly-carbene complexes, two triphenylene-based planar tridentate N-heterocyclic carbenes and their corresponding tri-gold complexes were synthesized. Molecular structures of the tert-butyl substituted tritopic free carbene and the tri-nuclear gold complex were determined experimentally.
Yun-Ting, Wang +4 more
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SILVER(I) N-HETEROCYCLIC CARBENES
Comments on Inorganic Chemistry, 2004AbstractFor Abstract see ChemInform Abstract in Full Text.
Ivan J. B. Lin, Chandra Sekhar Vasam
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Are There Carbenes in N‐Heterocyclic Carbene Organocatalysis?
Angewandte Chemie International Edition, 2017AbstractAzolium cations are widely employed in organocatalysis to catalyse highly valuable synthetic processes in the presence of a base. These reactions are called “N‐heterocyclic carbene catalysis”, based on the assumption that they are initiated by the formation of a free carbene through deprotonation, which can then react with the substrates and ...
Sascha Gehrke, Oldamur Hollóczki
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Abnormal N-heterocyclic carbenes
Coordination Chemistry Reviews, 2007Abstract Metal NHC complexes have been known for over 50 years, but only during the last 15 have they been studied as potential catalysts. N-heterocyclic carbene (NHC) complexes are often more straightforward to make than the phosphine analogues with which they are often compared, are generally more stable, less odorous and on many occasions have ...
Polly L. Arnold, Stephen Pearson
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F-block N-heterocyclic carbene complexes
Chemical Communications, 2006N-Heterocyclic carbenes (NHCs) can bind as two-electron sigma-donor ligands to lanthanide and actinide metal cations. In this review we summarise how the incorporation of an anionic group (alkoxide or amido), to form heterobidentate NHC ligands, allows the synthesis of a range of f-block NHC adducts.
Arnold, Plly L, Liddle, Stephen T
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A tropylium annulated N-heterocyclic carbene
Chemical Communications, 2020Derivatives of the cationic tropylium annulated imidazolylidene ITrop+ are obtained by hydride abstraction from related cycloheptatriene compounds.
Sebastian Appel +2 more
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