نتایج جستجو برای: heck cross coupling
تعداد نتایج: 633215 فیلتر نتایج به سال:
Chapter 1 gives the reader a background on cross-coupling reactions, in particular palladium mediated couplings. Furthermore the importance of ligands, including phosphines and N-heterocyclic carbenes (NHC), in such cross-coupling reactions is explored. Chapter 2 provides a background to the reductive lithiation of phosphines, followed by an account of our investigation of BINAP functionalisati...
Aqueous Mizoroki-Heck coupling reactions under microwave irradiation (MW) were carried out with a colloidal Pd nanocatalyst stabilized with poly(N-vinylpyrrolidone) (PVP). Many stilbenes and novel heterostilbenes were achieved in good to excellent yields starting from aryl bromides and different olefins. The reaction was carried out in a short reaction time and with low catalyst loading, leadin...
A series of general and selective Pd(II)-catalyzed Heck reactions were investigated under mild reaction conditions. The first protocol has been developed employing an imidazole-based secondary phosphine oxide (SPO) ligated palladium complex (6) as a precatalyst. The catalytic coupling of aryl halides and olefins led to the formation of the corresponding coupled products in excellent yields. A v...
A three-component coupling of vinyl triflates and boronic acids to alkenes catalyzed by palladium is reported. Using 1,3-dienes, selective 1,2-alkene difunctionalization is observed, whereas the use of terminal alkenes results in 1,1-alkene difunctionalization. The reaction outcome is attributed to the formation of stabilized, cationic Pdπ-allyl intermediates to regulate β-hydride elimination. ...
Carbon-carbon cross-coupling reactions are essential synthetic tools for synthesizing polymers, natural products, agrochemicals, and pharmaceuticals. Therefore, new catalysts that function with greater efficiency functional group tolerance being researched. We have prepared ferrocenylimine monodentate N P donor ligands N^N N^P bidentate chelating (L1 to L4) employed in stabilizing palladium ion...
During the past decades, building on the seminal contributions of Overman and Shibasaki, the asymmetric intramolecular Heck reaction has been successfully applied in natural product synthesis to install tertiary and quaternary stereocenters. In stark contrast, the intermolecular version of this asymmetric transformation has not reached the same level of development and its synthetic utility rem...
A green protocol for the in situ synthesis of Pd nanoparticles on chitosan beads (Pd NPs-CS) is reported without need to use any toxic reducing agents. The preparation catalyst was performed using a simple coordination reaction between prepared and palladium ions NPs-CS). obtained characterized by different techniques, including SEM, EDX, DRX, FTIR analyses. NPs-CS investigated Suzuki–Miyaura c...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید