Solid Supported Palladium(0) Nanoparticles: An Efficient Heterogeneous Catalyst for Regioselective Hydrosilylation of Alkynes and Suzuki Coupling of β-Arylvinyl Iodides
Investigation of the factors controlling the regioselectivity of the hydrosilylation of alkynes catalysed by trans-di-μ-hydridobis(tricylcohexylphosphine)bis(silyl)diplatinum complexes
作者:Constantinos A. Tsipis
DOI:10.1016/s0022-328x(00)93435-1
日期:1980.3
The hydrosilylation of terminal and internalalkynes and also of some hydroxy-alkynes catalysed by trans-di-μ-hydridobis(tricyclohexylphosphine)bis(silyl)diplatinum complexes is described. These diplatinum complexes are very efficient catalysts for such hydrosilylations; high yields (80–98%) can be obtained under mild conditions with a catalysts/reactant ratio of 10−4–10−5/1. Addition of hydrosilanes
Photogeneration of very active homogeneous catalysts using laser light excitation of iron carbonyl precursors
作者:James C. Mitchener、Mark S. Wrighton
DOI:10.1021/ja00394a060
日期:1981.2
conclude that photolysis of Fe(CO)5 or Fe3(CO)12 yeidls an exceedingly active catalyst. The active catalyst is likely not an excited state species since the excited lifetimes of Fe(CO)5 or Fe3(CO)12 are too short to effect catalysis. The active species is likely an unsaturated ground state species photoproduced by loss of CO from Fe(CO)5 or Fe-Fe bond cleavage in Fe3(CO)12. Very high turnover rates for
摘要:为了总结我们的主要发现,我们得出结论,Fe(CO)5 或 Fe3(CO)12 的光解是一种非常活跃的催化剂。活性催化剂可能不是激发态物质,因为 Fe(CO)5 或 Fe3(CO)12 的激发寿命太短而无法实现催化作用。活性物质可能是由 Fe(CO)5 中的 CO 损失或 Fe3(CO)12 中的 Fe-Fe 键断裂光产生的不饱和基态物质。已经发现烯烃异构化和氢化硅烷化的转换率非常高。此外,实现了非常高的周转数(每摩尔最初存在的 Fe 的产物摩尔数)。例如,当使用大约 0.01 m Fe(CO)5 的单次闪蒸产生大约 50% 的纯 1-戊烯转化率时,周转数超过 400。随后的闪蒸产生更大程度的转化以最终完全平衡线性戊烯。高光强度似乎不会改变产品分布,其中可能有多种产品(烯烃 + HSiEt3)。数据表明,非常高的光强度可用于以高观察速率和高量子效率(远大于 1)生产产品。(作者)
Tsipis, Constantinos A.; Tsoleridis, Constantinos A., Canadian Journal of Chemistry, 1980, vol. 58, p. 361 - 368
作者:Tsipis, Constantinos A.、Tsoleridis, Constantinos A.
DOI:——
日期:——
High Oxidation State Rhodium and Iridium Bis(silyl)dihydride Complexes Supported by a Chelating Pyridyl-Pyrrolide Ligand
作者:Jennifer L. McBee、Jose Escalada、T. Don Tilley
DOI:10.1021/ja9035169
日期:2009.9.9
New rhodium and iridium complexes containing the bidentate ligand 3,5-diphenyl-2-(2-pyridyl)pyrrolide (PyPyr) were prepared. The bis(ethylene) complex (PyPyr)Rh(C2H4)(2) (3) reacted with HSiEt3, HSiPh3, and (HSiBuPh2)-Bu-t to produce the 16-electron Rh(V) bis(silyl)dihydrides (PyPyr)Rh(H)(2)(SiEt3)(2) (8), (PyPyr)Rh(H)(2)(SiPh3)(2) (9), and (PyPyr)Rh(H)(2)((SiBuPh2)-Bu-t)(2) (10), respectively. The analogous Ir(V) bis(silyl)dihyride (PyPyr)Ir(H)(2)(SiPh3)(2) (11) has also been synthesized. X-ray crystallography reveals that 9-11 adopt a coordination geometry best described as a bicapped tetrahedron. Silane elimination from 9 and 10 occurred in the presence of either HSiEt3 or PPh3. Mechanistic studies of the silane exchange process involving 10 and free HSiEt3 (to give 8) indicate that this process occurs by rate-limiting reductive elimination of (HSiBuPh2)-Bu-t from 10 to generate a 14-electron Rh(III) intermediate of the type (PyPyr)Rh(H)((SiBuPh2)-Bu-t).
Hydrosilylation of 1-pentyne by triethylsilane catalyzed by phosphine-rhodium complexes