描述了两种可靠且有效的途径制备双(五氟苯基)硼烷1。三步过程使用-C 6 F 5转移剂Me 2 Sn(C 6 F 5)2生成氯硼烷ClB(C 6 F 5)2,随后将其通过硅烷处理转化为1,收益率为62%。或者,可以从B(C 6 F 5)3和Et 3以69%的收率制得1通过在苯中在60°C下加热两种试剂3天来实现SiH。硼烷1是固态的二聚体,如通过X射线晶体学分析所确定的。然而,在芳族溶剂中,存在可检测量的单体硼烷(二聚物:单体之比≈4.5∶1)。二聚体易于与单体解离,再加上硼烷的高亲电性,使得1在芳族溶剂中成为非常活泼的加氢硼化试剂。在供体溶剂(例如四氢呋喃)中不会进行硼氢化。多种烯烃的调查和炔底物表明,1氢硼酸盐具有与常用试剂(如9-BBN)相当的区域选择性和化学选择性,但速率要快得多。试剂的第二个独特特征是在烯烃加氢硼化产物中发生硼烷基迁移的设备。该性质可用于获得硼氢化的热力学产物,其
upon the reaction of arylacetylenes with Piers’ borane (HB(C6F5)2) is reported. Isotope labeling experiments and DFT computations indicate that the mechanism of this complex transformation commences with a series of unprecedented 1,2-carboborations, followed by an electrocyclization and two skeletalrearrangements.
电环化:报道了芳基乙炔与Piers'硼烷(HB(C 6 F 5 ) 2 )反应形成四芳基-四氢戊二烯。同位素标记实验和 DFT 计算表明,这种复杂转变的机制始于一系列前所未有的 1,2-碳硼化,然后是电环化和两次骨架重排。
η3-Vinylborane Complexes of Platinum and Nickel: Borataallyl- and Alkyl/Borataalkene-Like Coordination Modes
作者:Kristopher B. Kolpin、David J. H. Emslie
DOI:10.1002/anie.200906931
日期:2010.4.1
PhHCCH‐B(C6F5)2 reacts with zero‐valent Group 10 transition‐metal precursors to form η3‐vinylborane complexes. The platinum tri‐tert‐butylphosphine complex exhibits an η3‐borataallyl‐like coordinationmode whereas the nickel bis(triphenylphosphine) complex tends towards alkyl/borataalkene coordination.
Unusual borane addition to conjugated dienylphosphanes under frustrated Lewis pair conditions
作者:Sergei Krupski、Gerald Kehr、Constantin G. Daniliuc、Gerhard Erker
DOI:10.1039/c5dt03879k
日期:——
Dimesitylphosphinoisoprene reacts with a series of R-B(C6F5)2 boron Lewis acids by isomerization and subsequent 1,4-P/B addition to give the corresponding heterocyclic phosphonium/borate zwitterionic products.
Reactions of a Dimethylxanthene‐Derived Frustrated Lewis Pair with Silanes and Stannanes
作者:Ili Zulkifly、Andrey V. Protchenko、M. Ángeles Fuentes、Jamie Hicks、Simon Aldridge
DOI:10.1002/zaac.202200110
日期:2022.10.14
readily), and such processes are thought to be mechanistically similar to related rearrangements occurring with the boranes HBpin and HBcat. By contrast, the activation of the weaker Sn−H bonds found in stannanes occurs more readily, even for bulkier substrates, and the stannyl-phosphonium borohydrides 1iPr(SnnBu3)(H) and 1iPr(SnPh3)(H) are obtained from the room temperature reactions with nBu3SnH and Ph3SnH
Unsaturated Vicinal Frustrated Lewis Pair Formation by Electrocyclic Ring Closure and Their Reaction with Nitric Oxide
作者:Thomas Özgün、Guo-Qiang Chen、Constantin G. Daniliuc、Alison C. McQuilken、Timothy H. Warren、Robert Knitsch、Hellmut Eckert、Gerald Kehr、Gerhard Erker
DOI:10.1021/acs.organomet.6b00627
日期:2016.11.14
The Lewis acidic beta-styryl-B(C6F5)(2) reagent 6a undergoes a clean 1,1-carboboration reaction with 1-(PMes(2))-2-cyclohexenyl acetylene 9 at 60 degrees C to give the vicinal P/B-substituted conjugated triene product 10a. At 80 degrees C this undergoes a stereoselective thermally induced disrotatory electrocyclic ring closure to give the cyclohexadiene-derived P/B system 11. Subsequent TEMPO oxidation gave the substituted phenylene-bridged P/B product 12. Both 11 and 12 are active phosphane/borane frustrated Lewis pairs (FLPs). The FLP 11 reacts in a typical way with phenylacetylene to give the phosphonium/alkynylborate product 13. Compound 12 cleaves dihydrogen at near ambient conditions to give the respective phosphonium/hydridoborate zwitterion 14. Both the FLPs 11 and 12 cooperatively add P/B to the nitrogen atom of nitric oxide (NO) within minutes at room temperature to give the persistent P/B FLPNO center dot radicals 19 and 21, respectively (both characterized by X-ray diffraction and by EPR spectroscopy). The FLPs 11 and 12 are thermally robust. At elevated temperatures (11: 75 degrees C, 12: 100 degrees C) they undergo a coupling reaction with dimethyl acetylenedicarboxylate with carbon-carbon bond activation at a P-mesityl substituent.