A ligand-free palladium-catalyzed aerobic oxidative carbonylation of amines for the synthesis of ureas, particular unsymmetrically N,N′-disubstituted ureas, which cannot be accessed by any other palladium-catalyzed oxidative carbonylation of amines to date, is presented. An array of symmetrical and unsymmetrical ureas were straightforwardly synthesized by using inexpensive, readily available, stable
Organic ligand-free carbonylation reactions with unsupported bulk Pd as catalyst
作者:Shujuan Liu、Hongli Wang、Xingchao Dai、Feng Shi
DOI:10.1039/c8gc00740c
日期:——
ligand-free conditions, namely, hydroaminocarbonylation of olefins, aminocarbonylation of aryliodides and oxidative carbonylation of amines, which almost cover all the known mechanisms in carbonylation reactions. Notably, the bulk Pdcatalyst system exhibited better catalytic activity than the classical homogeneous PdCl2/(2-OMePh)3P catalyst system. This study will create a momentous and new field of green
Synthetic Studies on<scp>l</scp>-Proline and (4<b>
<i>R</i>
</b>)-Hydroxy-<scp>l</scp>-proline Derivatives
作者:Cristina Minguillón、Teresa González、Olga Abad、M. Carmen Santano
DOI:10.1055/s-2004-822384
日期:——
The preparation of a number of l-proline and (4R)-hydroxy-l-proline derivatives to assess their enantioselectivity when applied to several techniques and experimental conditions is described. All the derivatives prepared incorporated at least one 3,5-disubstituted aromatic ring that contained nitro, chloro or methyl groups and were obtained by classical methods. In spite of the difficulties that arise from the presence of rotational isomers in most cases, the compounds studied are fully described by their 1H and 13C NMR spectra.