Three novel fullerothioureas derived from natural valine, phenylalanine, and tert‐leucine have been prepared by Prato's reaction of [60]fullerene and the corresponding aldehydes. These hybrids have been used as organocatalysts in a typical stereoselective nitro‐Michael addition reaction under homogeneous and neat conditions. The catalysts are easily recoverable by filtration, and are recyclable for at least five times. The addition products were obtained in excellent yields and stereoselectivities by using catalyst loadings of as low as 0.5 mol‐%.
ABSTRACT:The activity, F, of AgBr, AgI, PbF 2 , Ag 2 S, LiF, and CaF 2 in the catalyzed nucleation of poly(ethylene terephthalate) (PET) melts was determined using a nonisothermal differential scanning calorimetry (DSC) technique. A comparison with existing experimental data was made. It is established that the higher the melting temperature of the substrate the lower its activity as a crystallization core in the heterogeneous nucleation of PET. The lateral surface energy, s, the end surface energy, s e , the adhesion energy, b, and the difference between the surface energies at the substrate/melt, s s f , substrate/deposit, s*, and the total energy of misfit dislocations, E d [i.e., s s f 0 (s* 0 E d )] were calculated.
The cover picture shows the general structure of the first easily recoverable and reusable molecular chiral thioureas to be used as organocatalysts in asymmetric nitro‐Michael reactions. They were prepared by functionalization of amines obtained from [60]fullerene and aldehydes. The recovery of the catalysts is based on the low solubility of fullerene derivatives in different organic solvents, and they can be used at 0.5 mol‐% loading. The artwork is by P. Higuero and represents the easy recoverability of the catalysts after the goal of the catalytic process. Details are discussed in the Full Paper by R. Pedrosa et al. on page 2683 ff (DOI: http://onlinelibrary.wiley.com/doi/10.1002/ejoc.201601640/abstract).
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