NiH‐Catalyzed Migratory Defluorinative Olefin Cross‐Coupling: Trifluoromethyl‐Substituted Alkenes as Acceptor Olefins to Form
<i>gem</i>
‐Difluoroalkenes
a NiH-catalyzed migratory defluorinative coupling between two electronically differentiated olefins. A broad range of unactivated donor olefins can be joined directly to acceptor olefins containing an electron-deficient trifluoromethyl substituent in both intra- and intermolecular fashion to form gem-difluoroalkenes. This migratory coupling shows both site- and chemoselectivity under mild conditions
In Situ Generated Bulky Palladium Hydride Complexes as Catalysts for the Efficient Isomerization of Olefins. Selective Transformation of Terminal Alkenes to 2-Alkenes
作者:Delphine Gauthier、Anders T. Lindhardt、Esben P. K. Olsen、Jacob Overgaard、Troels Skrydstrup
DOI:10.1021/ja9108424
日期:2010.6.16
enriched substrates provided products without epimerization at the allylic stereogenic carbon centers. Finally, some mechanisticinvestigations were undertaken to understand the nature of the active in situ generated Pd-H catalyst. These studies revealed that the catalytic system is highly dependent on the large steric demand of the P(tBu)(3) ligand. The use of an alternative ligand, cataCXium PinCy, also
of carbon-carbon doublebonds is a central component of chemical manufacturing. One useful trick is to shift hydrogen atoms around to interconvert C=C isomers selectively. However, this approach typically requires precious metals. Kapat et al. now report that more-abundant nickel can catalyze rapid conversion of terminal olefins into internal olefins with high selectivity for trans geometry. The odd-electron
We report a new air‐stable PdI dimer, [Pd(μ‐I)(PCy2tBu)]2, which triggers E‐selective olefin migration to enamides and styrene derivatives in the presence of multiple functional groups and with complete tolerance of air. The same dimer also triggers extremely rapidC−Ccoupling (alkylation and arylation) at roomtemperature in a modular and triply selective fashion of aromatic C−Br, C−OTf/OFs, and
我们报告了一种新的空气稳定的Pd I二聚体[Pd(μI)(PCy 2 t Bu)] 2,它在存在多个官能团且具有完全耐受性的情况下触发E-选择性烯烃向酰胺和苯乙烯衍生物的迁移空气 同一二聚体还可以在室温下以模块化和三重选择性的方式在聚(假)卤代芳烃中以芳族C-Br,C-OTf / OF和C-Cl键的形式快速触发C-C偶联(烷基化和芳基化)在具有邻位C-OTf的取代基的底物上显示出比以前的Pd I二聚体更好的活性。