<i>para</i>-Selective arylation and alkenylation of monosubstituted arenes using thianthrene <i>S</i>-oxide as a transient mediator
作者:Xiao-Yue Chen、Xiao-Xue Nie、Yichen Wu、Peng Wang
DOI:10.1039/d0cc00641f
日期:——
Using thianthrene S-oxide (TTSO) as a transient mediator, para-arylation and alkenylation of mono-substituted arenes have been demonstrated via a para-selective thianthrenation/Pd-catalyzed thio-Suzuki-Miyaura coupling sequence under mild conditions. This reaction features a broad substrate scope, and functional group and heterocycle tolerance. The versatility of this approach was further demonstrated
HPLC separation of 2-aryloxycarboxylic acid enantiomers on chiral stationary phases
作者:A. A. Tumashov、S. A. Vakarov、L. Sh. Sadretdinova、E. N. Chulakov、G. L. Levit、V. P. Krasnov、V. N. Charushin
DOI:10.1007/s11172-021-3165-8
日期:2021.5
reversed-phase HPLC on popular chiralstationaryphases. The best separation parameters were achieved on the chiralphases with the polysaccharide base Chiralcel OD-H and Chiralpack AD under the normal-phase HPLC conditions. The (S)- and (R)-enantiomers of 2-(1-naphthyloxy)- and 2-(2-iodophenoxy)propionic acids with enantiomeric excess ee >99% were isolated using preparative chiralHPLC.
New approaches to the asymmetric synthesis of non-proteinogenic α-amino acids and dipeptides through chiral β-lactam intermediates
作者:Iwao Ojima、Hauh-Jyun C. Chen、Xiaogang Qiu
DOI:10.1016/s0040-4020(01)86038-5
日期:1988.1
Novel and effective routes to optically pure aromatic α-amino acids, α-methyl-α-amino acids and their derivatives including dipeptides are developed via homochiral β-lactams which are obtained through asymmetric [2+2] cycloadditions of ketenes to imines.