Acrylates spectroscopic data

For acyclic nitronates, the reaction rate can depend on the configuration of the dipole. On the basis of 15N NMR spectroscopic data, it was demonstrated (338a) that thermodynamically more favorable lruns isomers of nitronates (1) are much less reactive in [3+ 2]-addition to methyl acrylate (Scheme 3.128). 

The selectivity for VA may be explained, in part, by the relative energies of the orbitals on the olefins and platinum. Meester et al. have reported orbital energies for platinum, VA and methyl acrylate in trans-PtClo(olefin)(pyridine) conplexes based on spectroscopic data (2i). Their results indicate a closer match for methyl acrylate in the energies of the unfilled olefin and platinum orbitals, but a closer match for VA in the energies of the filled orbitals. Apparently, the o-bond interaction predominates in determining the relative reaction rates (and product stabilities) for these olefin substitutions. The fact that methylmethacrylate does not react at all is probably due to steric hindrance of the additional methyl group on the double bond. A similar argument can... 

Compound 183 undergoes B—N cyclodehydration to give the expected isoquinoline 184. Sodium borohydride as a reductive agent was ineffective. However, sodium cyanoborohydride reduction of 184 after prolonged interaction provides tetrahydroisoquinoline 185, which was transformed into an amido ester 186 with ethyl acrylate via Michael addition. The latter can be converted to the desired tricyclic system 187 via Dieckmann cycli-zation.As expected (i-kcto ester 187 is a mixture ofketo—enol tautomers, as proven by its spectroscopic data and a positive FeCls-MeOH test. It is likely that this is the first successful way for the syntheses of l,l-dimethylbenzo[a] quinolizidin-2-ones (Scheme 50) (83JOC1075). 

According to X-ray data, such acrylates or ( )-Cp-substituted enoates exhibit a synperiplanar C— Ha/C—O relationship in the solid state which also seems to predominate in solution. In solution, however, spectroscopic evidence indicates an equilibrium between conformers (H) and (I), where the... 

Spectroscopic evidence for association through the sharing of carboxylate cations has been reported (37) (the phenomenon is discussed in Chapter 15) for surfactant-acrylic acid copolymer interactions. This dependence on surface carboxylate groups (Figure 17) is not observed in cellulose ether or in HEUR 200 formulations. This observation is made in reviewing all of the data, and probably reflects only the extreme surfactant sensitivity of HEUR 200. 

Raman fibre optics has been used to study the emulsion homopolymerisations of styrene and n-butyl acrylate (35). An IR spectroscopic technique for the examination of radical copolymerisations of acryl and vinyl monomers was developed. A comparative study of the copolymerisation of model monomer pairs was made using monofunctional and polyfunctional compounds. The data established the role of structural-physical transformations, involved in the formation of crosslinked polymers, on the copolymerisation kinetics and on the nonuniformity of distribution of crosslinks in the copolymers formed (151). Raman fibre optics of polymerisation of acrylic terpolymers was also used to monitor as well as an on-line measurement of morphology/composition (66). The high temperature (330 °C) cure reaction of 4-phenoxy-4 -phenyl-ethynylbenzophenone was monitored using a modulated fibre optic FT-Raman spectrometer (80). 

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