The access to a large semirigid macrocycle exhibiting two m,m’-terphenyl units was carried out by a suite of Suzuki-Miyaura, Sonogashira cross-coupling and CuAAC (“click”) reactions. The target macrocycle exhibits two triazole and two ester protected carboxyl units of great use for the development of further applications.
Transition metal complexes of N-heterocyclic carbenes, method of preparation and use in transition metal catalyzed organic transformations
申请人:Organ G. Michael
公开号:US20070073055A1
公开(公告)日:2007-03-29
The present invention relates to catalysts of transition metal complexes of N-heterocyclic carbenes, their methods of preparation and their use in chemical synthesis. The synthesis, ease-of-use, and activity of the compounds of the present invention are substantial improvements over in situ catalyst generation. Further, the transition metal complexes of N-heterocyclic carbenes of the present invention may be used as precatalysts in metal-catalyzed cross-coupling reactions.
Is Pd<sup>II</sup>-Promoted σ-Bond Metathesis Mechanism Operative for the PdPEPPSI Complex-Catalyzed Amination of Chlorobenzene with Aniline? Experiment and Theory
作者:Feiqun Wang、Lei Zhu、Yunfei Zhou、Xiaoguang Bao、Henry F. Schaefer
DOI:10.1002/chem.201406109
日期:2015.3.2
Reduction of the PdPEPPSI precatalyst to a Pd0 species is generally thought to be essential to drive Buchwald–Hartwig amination reactions through the well‐ documented Pd0/PdII catalytic cycle and little attention has been paid to other possible mechanisms. Considered here is the PdPEPPSI‐catalyzed aryl amination of chlorobenzene with aniline. A neat reaction system was used in new experiments, from which