Direct Synthetic Route to Functionalized 1,2-Azaborinines
作者:Holger Braunschweig、K. Geetharani、J. Oscar C. Jimenez-Halla、Marius Schäfer
DOI:10.1002/anie.201309707
日期:2014.3.24
A new catalytic syntheticroute to functionalized 1,2‐azaborinines has been developed by the [2+2]/[2+4] cycloaddition reactions of di‐tert‐butyliminoboranes and alkynes in presence of a rhodium catalyst. The first examples of ferrocene‐functionalized azaborinines have been synthesized using this strategy. Moreover, the regioselectivity of this reaction can be controlled by the formation of an intermediate
Intriguing migrations in transient iminoborane adducts: two new pathways to aminoboranes
作者:Lena Winner、Guillaume Bélanger-Chabot、Mehmet Ali Celik、Marius Schäfer、Holger Braunschweig
DOI:10.1039/c8cc05220d
日期:——
Two unusual reactions were demonstrated with iminoboranes, both leading to aminoboranes of the type R2BNR2. In one case, a carboboration of di(tert-butyl)iminoborane with B(C6F5)3 led to (tBu)(C6F5)B–N(tBu)(B(C6F5)2). In the other, a transient IDipp (1,3-di(2,6-diisopropylphenyl)imidazol-2-ylidene) adduct of MesBNtBu undergoes a shift of one carbene-bound Dipp substituent to the iminoborane nitrogen
用亚氨基硼烷证明了两个不同寻常的反应,均导致生成R 2 B NR 2型氨基硼烷。在一种情况下,二(叔丁基)亚氨基硼烷与B(C 6 F 5)3碳硼化导致(t Bu)(C 6 F 5)B–N(t Bu)(B(C 6 F 5)2)。在另一种情况下,MesBN t Bu的瞬时IDipp(1,3-二(2,6-二异丙基苯基)咪唑-2-亚烷基)加合物经历了一个卡宾键结合的Dipp取代基向亚氨基硼烷氮原子的转移,生成(1 -Dipp-咪唑-2-基)(Mes)B–N(Dipp)(t卜)。DFT机理研究表明,硼烷·亚氨基硼烷加合物在碳硼化反应中处于中间状态。
Cleavage of BN triple bonds by main group reagents
作者:Lena Winner、Alexander Hermann、Guillaume Bélanger-Chabot、Oscar F. González-Belman、J. Oscar C. Jiménez-Halla、Hauke Kelch、Holger Braunschweig
DOI:10.1039/c8cc02317d
日期:——
the highly crowded iminoborane Ter–NB–TMP (TMP = 2,2,6,6-tetramethylpiperidyl, Ter = 2,6-(diphenylmethyl)-4-tert-butylphenyl) can be forced to react with Pip–CC–Pip (Pip = piperidyl) at 60 °C. The reaction product is the apparent result of Pip–CC insertion into the iminoborane BN bond.
The Reactivities of Iminoboranes with Carbenes: BN Isosteres of Carbene-Alkyne Adducts
作者:Holger Braunschweig、William C. Ewing、K. Geetharani、Marius Schäfer
DOI:10.1002/anie.201409699
日期:2015.1.26
The first examples of adducts of cyclic alkyl(amino) carbenes (CAAC) and N‐heterocyclic carbenes (NHCs) with iminoboranes have been synthesized and isolated at low temperature (−45 °C). The adducts show short BN bonds and planarity at boron, mimicking the structures of the isoelectronic imine functionality. When di‐tert‐butyliminoborane was reacted with 1,3‐bis(isopropyl)imidazol‐2‐ylidene (IPr),
The B-N Bond in Some Aminoboranes and an Iminoborane, Studied by<sup>11</sup>B and<sup>15</sup>N NMR Spectroscopy and DFT Methods
作者:Bernd Wrackmeyer
DOI:10.1002/zaac.201500653
日期:2015.11
15N NMR spectra of several aminoboranes (Me2B–NMe2, Cl2B–NMe2, Br2B–NMe2, OCH2CH2OB–NMe2), three N-pyrrolylboranes, and an iminoborane (tBu–B≡N–tBu) was measured. The spin-spin coupling constants 1J(15N, 11B) were resolved at elevated temperatures. In the case of the iminoborane at 105 °C, the coupling constant 1J(14N,11B) = 57 Hz could also be determined from the 11B NMR spectrum [from 15N NMR 1J(15N