A series of silylated triarylphosphines was synthesized. Hydrosilylation reactions of styrene with triethoxysilane catalyzed by RhCl3/silylated triarylphosphine complexes were investigated. The complexes RhCl3/phenylbis(4‐trimethylsilylphenyl)phosphine and RhCl3/tris(4‐trimethylsilylphenyl)phosphine exhibited higher activity as well as greater β‐adduct selectivity, and no unsaturated product was obtained
Thermal properties of variously substituted poly[(disilanylene)oligophenylenes], [(SiR1R2SiR1R2)(p-C6H4)m]n (R1=R2=Me, R1=R2=Et, and R1=Ph, R2=Me, m=1–4) were investigated. The thermogravimetric analysis of the polymers in the range of 20–1000°C showed rapid weight loss starting from about 400°C. The total weight loss of the polymers at 1000°C was calculated to be 54.5–75.5% based on the initial weight
各种取代的聚[(二亚硅烷基)低聚亚苯基],[(SiR 1 R 2 SiR 1 R 2)(p -C 6 H 4)m ] n(R 1 = R 2 = Me,R 1 = R 2 = Et,R 1 = Ph,R 2 = Me,m= 1–4)进行了调查。在20–1000°C范围内对聚合物进行热重分析表明,从约400°C开始,重量迅速下降。基于聚合物的初始重量,聚合物在1000°C时的总重量损失为54.5-75.5%。对聚合物进行热解得到的挥发性产物的GC-MS分析,其中R 1 = R 2 = Me,m = 2,R 1 = R 2 = Et,m = 1–4在500°C时表明形成了硅Si-Si和Si-亚苯基键断裂产生的含低聚物,主要是。H(C 6 H 4)l H(l在m = 3和4的聚合物的热解中也观察到了= 1–4)。还使用1,2-二苯基四甲基二硅烷检查了聚合物降解的模型反应。
Effect of triarylphosphane ligands on the rhodium-catalyzed hydrosilylation of alkene
作者:Mei Xue、Jiayun Li、Jiajian Peng、Ying Bai、Guodong Zhang、Wenjun Xiao、Guoqiao Lai
DOI:10.1002/aoc.3092
日期:2014.2
functionalized triarylphosphaneligands are characterized by a very high catalytic effectiveness for the hydrosilylation of alkene. Among these catalysts tested, RhCl3/diphenyl(2‐(trimethylsilyl)phenyl)phosphane (8a) exhibited excellent catalytic properties. Using this silicon‐containing phosphane ligand for the rhodium‐catalyzed hydrosilylation of styrene, both higher conversion of alkene and higher β‐adduct
B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Catalyzed Diastereoselective Formal (4 + 1)-Cycloaddition of Vinylcyclopropanes and Et<sub>2</sub>SiH<sub>2</sub>
作者:Peng-Wei Long、Martin Oestreich
DOI:10.1021/acs.orglett.1c01565
日期:2021.6.18
afford 3,4-disubstituted silolanes is reported. The reaction sequence commences with the known B(C6F5)3-catalyzed alkene hydrosilylation with dihydrosilanes. Cleavage of the remaining Si–H bond in the hydrosilylation product assisted by B(C6F5)3 leads to formation of a cyclopropane-stabilized silyliumion. The activated cyclopropane ring is then opened by the in situ-generated borohydride accompanied
据报道,乙烯基环丙烷和 Et 2 SiH 2的正式 (4 + 1)-环加成反应得到 3,4-二取代的硅酮。反应顺序从已知的B(C 6 F 5 ) 3催化的烯烃与二氢硅烷的氢化硅烷化开始。在 B(C 6 F 5 ) 3 的帮助下,氢化硅烷化产物中剩余的 Si-H 键断裂导致形成环丙烷稳定的甲硅烷离子。活化的环丙烷环随后被原位生成的硼氢化物打开,伴随着对硅酮的闭环。非对映选择性通过机械模型合理化。
B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Catalyzed Hydrosilylation of Vinylcyclopropanes
作者:Peng-Wei Long、Tao He、Martin Oestreich
DOI:10.1021/acs.orglett.0c02751
日期:2020.9.18
reported. For the majority of VCPs, little or no ring opening of the cyclopropyl unit is observed. Conversely, for VCPs with bulky R groups, such as ortho-substituted aryl rings or branched alkyl residues, ring opening is the exclusive reaction pathway. This finding is explained by the thwarted hydride delivery to a sterically shielded, β-silicon-stabilized cyclopropylcarbinyl cation intermediate.
据报道,强硼路易斯酸B(C 6 F 5)3催化乙烯基环丙烷(VCP)的硅氢化。对于大多数VCP,观察到很少或没有环丙基单元的开环。相反,对于具有庞大R基团的VCP,例如邻位取代的芳基环或支链烷基残基,开环是唯一的反应途径。这一发现可以通过阻止氢化物向空间屏蔽的,β-硅稳定的环丙基羰基阳离子中间物的传递来解释。