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Inside Back Cover: Transition‐Metal‐Like Behavior of Monovalent Boron Compounds: Reduction,Migration, and Complete Cleavage of CO at a Boron Center (Angew. Chem. Int. Ed. 28/2018) 下载免费PDF全文
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Marco Nutz Bitupon Borthakur Dr. Rian D. Dewhurst Andrea Deißenberger Dr. Theresa Dellermann Dr. Marius Schäfer Dr. Ivo Krummenacher Prof. Ashwini K. Phukan Prof. Dr. Holger Braunschweig 《Angewandte Chemie (International ed. in English)》2017,56(27):7975-7979
Although the metathesis of metal–boron double bonds with elemental chalcogenides is an established process, no similar reactivity has been observed with element–nitrogen bonds. Such a reaction would provide a new route to iminoborane compounds (RB≡NR′), which have recently experienced renewed synthetic interest. Herein, we present the first observation of M=B/C=N metathesis reactions, which led to the isolation of a stable iminoborane in addition to further iminoborane cycloaddition products. 相似文献
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M. Sc. Małgorzata Krasowska Prof. Dr. Holger F. Bettinger 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(40):12858-12863
The addition of borylenes (RB) to prototypical carbon?carbon multiple bonds (ethyne, ethene) and the insertion into a C?H bond of methane involves weakly bound van der Waals complexes of the reaction partners according to computational chemistry methods. Geometries of all complexes were optimized using spin‐component scaled second‐order Møller–Plesset perturbation theory (SCS‐MP2) in combination with a quadruple‐ζ (def2‐QZVP) basis set. Energies were further refined using the coupled‐cluster (CCSD(T)) method in combination with basis sets up to quadruple‐ζ quality (def2‐QZVP and aug‐cc‐pVTZ). All of the complexes of borylenes studied correspond to shallow minima on their potential‐energy surfaces. Borylene complexes with ethyne are the most stable and those with methane are the least stable ones. Aminoborylene complexes BNHR with ethyne and ethene are stabilized mainly by NH ??? π interactions. Symmetry‐adapted perturbation theory (SAPT) was performed to analyze the nature of the interaction between borylene molecules and hydrocarbons. Most of the ethyne complexes are dominated by electrostatic interactions, whereas for most of the ethene and all of the methane complexes the interaction is mainly dispersive. 相似文献
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Isolation of a Bis(oxazol‐2‐ylidene)–Phenylborylene Adduct and its Reactivity as a Boron‐Centered Nucleophile 下载免费PDF全文
Dr. Lingbing Kong Dr. Yongxin Li Dr. Rakesh Ganguly Prof. Dr. Dragoslav Vidovic Prof. Dr. Rei Kinjo 《Angewandte Chemie (International ed. in English)》2014,53(35):9280-9283
An isolable phenylborylene species supported by two oxazol‐2‐ylidene ligands was synthesized and structurally characterized. Computational studies revealed the presence of lone‐pair electrons on the boron atom in this molecule; therefore, there are eight electrons around the three‐coordinate boron center. The nucleophilic property was confirmed by the reactions with trifluoromethanesulfonic acid and [(thf)Cr(CO)5], which gave the corresponding conjugate acid and a chromium–borylene complex, respectively. 相似文献
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Dudekula Sharmila K. Yuvaraj Subrat Kumar Barik Dipak Kumar Roy Kiran Kumarvarma Chakrahari Rongala Ramalakshmi Bijan Mondal Dr. Babu Varghese Prof. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(45):15219-15225
The synthesis, structural characterization, and reactivity of new bridged borylene complexes are reported. The reaction of [{Cp*CoCl}2] with LiBH4 ? THF at ?70 °C, followed by treatment with [M(CO)3(MeCN)3] (M=W, Mo, and Cr) under mild conditions, yielded heteronuclear triply bridged borylene complexes, [(μ3‐BH)(Cp*Co)2(μ‐CO)M(CO)5] ( 1 – 3 ; 1 : M=W, 2 : M=Mo, 3 : M=Cr). During the syntheses of complexes 1 – 3 , capped‐octahedral cluster [(Cp*Co)2(μ‐H)(BH)4{Co(CO)2}] ( 4 ) was also isolated in good yield. Complexes 1 – 3 are isoelectronic and isostructural to [(μ3‐BH)(Cp*RuCO)2(μ‐CO){Fe(CO)3}] ( 5 ) and [(μ3‐BH)(Cp*RuCO)2(μ‐H)(μ‐CO){Mn(CO)3}] ( 6 ), with a trigonal‐pyramidal geometry in which the μ3‐BH ligand occupies the apical vertex. To test the reactivity of these borylene complexes towards bis‐phosphine ligands, the room‐temperature photolysis of complexes 1 – 3 , 5 , 6 , and [{(μ3‐BH)(Cp*Ru)Fe(CO)3}2(μ‐CO)] ( 7 ) was carried out. Most of these complexes led to decomposition, although photolysis of complex 7 with [Ph2P(CH2)nPPh2] (n=1–3) yielded complexes 9 – 11 , [3,4‐(Ph2P(CH2)nPPh2)‐closo‐1,2,3,4‐Ru2Fe2(BH)2] ( 9 : n=1, 10 : n=2, 11 : n=3). Quantum‐chemical calculations by using DFT methods were carried out on compounds 1 – 3 and 9 – 11 and showed reasonable agreement with the experimentally obtained structural parameters, that is, large HOMO–LUMO gaps, in accordance with the high stabilities of these complexes, and NMR chemical shifts that accurately reflected the experimentally observed resonances. All of the new compounds were characterized in solution by using mass spectrometry, IR spectroscopy, and 1H, 13C, and 11B NMR spectroscopy and their structural types were unequivocally established by crystallographic analysis of complexes 1 , 2 , 4 , 9 , and 10 . 相似文献