Electronic and Structural Effects of Stepwise Borylation and Quaternization on Borirene Aromaticity
作者:Holger Braunschweig、Alexander Damme、Rian D. Dewhurst、Sundargopal Ghosh、Thomas Kramer、Bernd Pfaffinger、Krzysztof Radacki、Alfredo Vargas
DOI:10.1021/ja3110126
日期:2013.2.6
Room-temperature photolysis of the amino-boryl complex [(OC)(5)Cr=B=N(SiMe3)(2)] in the presence of a series of mono- or bis(boryl) alkynes bisbis-(dimethylamino)boryl}ethyne, 1-phenyl-2-bis-(dimethylamino)borylethyne, and 1-trimethylsilyl-2-bis-(dimethylamino)borylethyne led to the isolation of hitherto unknown borylborirenes in resonable yields, that is, [(RC=CR')(mu-BN(SiMe3)(2))] (7, R = B(NMe2)(2), R' = Ph; 8, R = R' = B(NMe2)(2); 9, R = B(NMe2)(2), R' = SiMe3). The borirenes were isolated and spectroscopically characterized by multinuclear NMR, IR, and UV/vis spectroscopy, crystallography, and elemental analysis. Reactivity studies of the borirenes demonstrated their behavior toward different Lewis bases. The isolated adducts and the parent borirenes were compared to 1,3-mesityl-2-phenylborirene and its adducts. To gain insight into the electronic structure and to evaluate the influence of the exocyclic groups, Density Functional Theory (DFT) calculations were carried out.
Chemie freier cyclischer vicinaler Tricarbonyl-Verbindungen (‘1,2,3-Trione') Teil 2. Redox-Reaktionen von 1,2,3-Trionen mit En-1,2-diolen (‘Reduktonen'), 2-Alkoxy-en-1-olen, En-1,2-diaminen und verwandten Spezies Für Teil 1, s. [1].
Chemistry of Free Cyclic Vicinal Tricarbonyl Compounds (‘1,2,3-Triones'). Part 2. Redox Reactions of 1,2,3-Triones with Ene-1,2-diols (‘Reductones'), 2-Alkoxy-en-1-ols, Ene-1,2-diamines, and Related Species. Midstanding carbonyl groups of cyclic 1,2,3-triones 4 possess outstanding electrophilic (electron-pair accepting) as well as oxidizing (one-electron accepting) properties. Their reactions with
TW2016/9759
申请人:——
公开号:——
公开(公告)日:——
PRAEFCKE, K.;KOHNE, B.;POULES, W.;POETSCH, E.
作者:PRAEFCKE, K.、KOHNE, B.、POULES, W.、POETSCH, E.
DOI:——
日期:——
Tuneable reduction of cymantrenylboranes to diborenes or borylene-derived boratafulvenes
Whereas the reduction of N-heterocyclic carbene (NHC)-stabilised cymantrenyldibromoboranes, (NHC)BBr2Cym, in benzene results in the formation of the corresponding diborenes (NHC)2B2Cym2, a change of solvent to THF yields a borylene analogue of the form (NHC)2BCym, stabilised through a boratafulvene/borafulvenium conformation.