674368-06-0Relevant academic research and scientific papers
Stereodivergent Alkyne Reduction by using Water as the Hydrogen Source
Rao, Santhosh,Prabhu, Kandikere Ramaiah
, p. 13954 - 13962 (2018)
A homogeneous Pd-catalyzed stereodivergent reduction of alkynes to Z and E alkenes by using H2O as the H2 source is presented. Mediated by a diboron reagent, the transfer hydrogenation has been accomplished to yield the desired geometrical isomer by rational ligand selection. The switchable stereoselectivity achieved using simple phosphine ligands is generally excellent. D2O has also been used as a D2 source for synthesizing the corresponding deuterated olefins. Supported by a gram-scale synthesis, the reaction can easily be scaled up making it an efficient way to prepare alkenes commercially as well. Mechanistic studies suggest formation of H?PdL2?OAc as the crucial step leading to the presence of two pathways involving H?Pd?B(OR)2 and molecular H2 as active intermediates.
Photo-cross-linking of polymethacrylates with stilbene chromophores in the side chains
Jahnke, Angelika,Beile, Bernhard,Meier, Herbert
experimental part, p. 2111 - 2124 (2012/01/31)
Methacrylates (=2-methylpropenoates) 5 with (E)-stilbene (=(E)-1,2-diphenylethene) building blocks on tethers of variable length were prepared (Scheme 2) and polymerized (i.e., 5→6; Scheme 3) in the presence of AIBN (=2,2′-azobis(2-methylpropanenitrile). 4-[(E)-2-Phenylethenyl] phenyl acetate (7) as model compound established the cyclodimerization as a single irreversible photoreaction. i.e., (7→8-11; Scheme 4) in the absence of oxygen. The solution photolysis of the polymers 6 provided a similar result, whereby [2π+2π] cycloadditions of stilbene units of neighboring tethers predominated. On the contrary, the desired photo-cross-linking of chaines occurred in the irradiation of polymer films. Copyright
