Institut für Anorganische Chemie, Julius-Maximilians Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Angew Chem Int Ed Engl. 2016 Nov 7;55(46):14464-14468. doi: 10.1002/anie.201608429. Epub 2016 Oct 12.
Reduction of carbene-borane adduct [(cAAC)BBr (CN)] (cAAC=1-(2,6-diisopropylphenyl)-3,3,5,5-tetramethylpyrrolidin-2-ylidene) cleanly yielded the tetra(cyanoborylene) species [(cAAC)B(CN)] presenting a 12-membered (BCN) ring. The analysis of the Kohn-Sham molecular orbitals showed significant borylene character of the B atoms. [(cAAC)B(CN)] was found to reduce two equivalents of AgCN per boron center to yield [(cAAC)B(CN) ] and fragmented into two-coordinate boron(I) units upon reaction with IMeMe (1,3,4,5-tetramethylimidazol-2-ylidene) to yield the corresponding tricoordinate mixed cAAC-NHC cyanoborylene. The analogous cAAC-phosphine cyanoborylene was obtained by reduction of [(cAAC)BBr (CN)] in the presence of excess phosphine.
碳烯-硼烷加合物[(cAAC)BBr(CN)]（cAAC=1-(2,6-二异丙基苯基)-3,3,5,5-四甲基吡咯烷-2-亚基）可被还原，得到呈现 12 元（BCN）环的四（氰基硼烷）物种[(cAAC)B(CN)]。Kohn-Sham 分子轨道的分析表明 B 原子具有显著的硼烯特征。[(cAAC)B(CN)]被发现每硼中心还原两个当量的 AgCN，生成[(cAAC)B(CN)]，并在与 IMeMe（1,3,4,5-四甲基咪唑-2-亚基）反应时断裂成二配位硼（I）单元，生成相应的三配位混合 cAAC-NHC 氰基硼烷。类似的 cAAC-膦氰基硼烷可通过在过量膦存在下还原[(cAAC)BBr(CN)]得到。
