Related Products of 108-47-4, Chemistry is the experimental science by definition. We want to make observations to prove hypothesis. For this purpose, we perform experiments in the lab. 108-47-4, Name is 2,4-Dimethylpyridine,introducing its new discovery.
Living polymerization of (o-(trimethylsilyl)phenyl)acetylene by molybdenum imido alkylidene complexes
syn-Mo(CHCMe2Ph)(NAd)[OCH(CF3)2]2(2,4-lutidine) (2a; Ad = 1-adamantyl) is a distorted trigonal bipyramid in which 2,4-lutidine occupies an axial position, a structure that results from addition of 2,4-lutidine to the CNO face of unstable pseudotetrahedral syn-Mo(CHCMe2Ph)(NAd)[OCH(CF3)2]2. 2a reacts with (o-(trimethylsilyl)phenyl)acetylene (o-TMSPA) solely via formation of an alpha-substituted metallacyclobutene intermediate (alpha addition) that opens to give a single rotamer of a disubstituted alkylidene complex. o-TMSPA is smoothly polymerized at a rate k(2a)[2a]0[o-TMSPA] when [2a] < 1 mM with a propagation rate constant k(2a) = 0.30 s-1 M-1. Additional studies confirmed that the disubstituted alkylidene propagating species is essentially base-free (K(2a) = 62 M-1) and that the propagating species is stable under catalytic conditions (25C). Other versions of the Mo(CHCMe2Ph)(NAd)[OCH(CF3)2]2(base) catalyst are either inactive (base = pyridine) or unstable (base = 2-(3-pentyl)pyridine). Mo(CHCMe2Ph)(NAr')(OC6F5)2(quinuclidine) (7; Ar' = 2,6-Me2C6H3) will also react smoothly with (o-(trimethylsilyl)phenyl)acetylene to give poly(o-TMSPA) with K7 = 1380 M-1 and k7 = 0.23 s-1 M-1. Low-polydispersity polyenes containing up to 150 equiv of o-TMSPA can be obtained readily using either catalyst. The thermodynamically most stable form of poly(o-TMSPA), which contains ~25 double bonds, is air-sensitive and has a significantly red-shifted lambda(max). o-t-BuPA also can be polymerized to give highly conjugated polyenes, but o-iPrPA, o-MePA, and phenylacetylene itself add to initiator 2a with decreasing alpha regiospecificity (73%, 60%, and 56%, respectively). A lack of regiospecificity we propose leads to polymers that do not have a pure head-to-tail structure, have a lower degree of conjugation, and have a progressively more blue-shifted lambda(max). We¡¯ll also look at important developments in the pharmaceutical industry because understanding organic chemistry is important in understanding health, medicine, the role of 108-47-4, and how the biochemistry of the body works.Related Products of 108-47-4
Reference£º
Chiral nitrogen ligands in late transition metal-catalysed asymmetric synthesis¡ªI. Addressing the problem of ligand lability in rhodium-catalysed hydrosilations,
Nitrogen-Containing Ligands for Asymmetric Homogeneous and Heterogeneous Catalysis