Phosphines Bearing Alkyne Substituents: Synthesis and Hydrophosphination Polymerization
作者:Sharonna Greenberg、Douglas W. Stephan
DOI:10.1021/ic9012284
日期:2009.9.7
A synthetic route is described for a series of phosphines bearing pendant alkyne substituents, from the conversion of BrC6H2R2C CR' (R = Me, i-Pr; R' = Ph, SiMe3) to [(mu-Br)Cu(Et2N)(2)PC6H2R2C CR'](2) and subsequently to Cl2PC6H2R2C CR' and H2PC6H2R2C CR'. Lithiation and subsequent alkylation yield the secondary phosphines R(H)PC6H2(i-Pr)(2)C CPh (R = CH(2)i-Pr, CH2Ph). Intermolecular hydrophosphination-polymerization is used to prepare the polymeric species [RPC6H2(i-Pr)(2)CH=CPh](n), which can then be sulfurized to give [RP(S)C6H2(i-Pr)(2)CH=CPh](n). The polymeric products were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and gel permeation chromatography. These data indicate a degree of polymerization (DPn) Of up to 60. Discussion of the mechanism is augmented with gas-phase density functional theory calculations.
A highly Lewis acidic triarylborane bearing peripheral o-carborane cages
作者:Kang Mun Lee、Jung Oh Huh、Taewon Kim、Youngkyu Do、Min Hyung Lee
DOI:10.1039/c1dt11064k
日期:——
mono-carborane substituted triarylborane. The enhanced fluoride ion affinity of 2 indicates an apparent additive effect of multiple carborane substitutions on the Lewis acidity enhancement of the triarylborane. The highly Lewis acidic nature of 2 was further utilized in evaluating the fluoride ion affinity of tris(pentafluorophenyl)borane (B(C6F5)3). A fluoride exchange reaction between [2F]− and B(C6F5)3
带有三个的三芳基硼烷(2)邻碳硼烷制备了芳基外围位置的笼,并通过X射线衍射研究确定了其晶体结构。治疗2与肯尼迪 在......的存在下 18冠6生成钾盐[ 2 F] -。紫外可见滴定实验四氢呋喃/高氧2(9/1 v / v)显示2个绑定氟化物的结合常数(离子ķ的4.8×10)4中号-1,这是为了数量级的大于ķ为单碳烷取代的三芳基硼烷。增强型氟化物离子亲和力为2表示多个碳硼烷取代对三芳基硼烷的Lewis酸度增强有明显的累加作用。的高度路易斯酸性性质2在评价中进一步利用氟化物 的离子亲和力 三(五氟苯基)硼烷 (B(C 6 F 5)3)。一种氟化物[ 2 F] -和之间的交换反应B(C 6 F 5)3 导致15倍的高亲氟性 B(C 6 F 5)3比2。的下路易斯酸性2相比B(C 6 F 5)3 被证实具有更大的阴极还原潜力。