Asymmetric synthesis of N-tosyl amino acids from N-sulfinyl α-amino-1,3-dithioketals
作者:Franklin A. Davis、Tokala Ramachandar、Jing Chai、Hiu Qiu
DOI:10.3998/ark.5550190.0011.804
日期:——
Hydrolysis of diastereomerically pure N-sulfinyl -amino-1,3-dithianes with 1,3-dibromo-5,5dimethylhydantoin gives N-tosyl -amino aldehydes which when subjected to a Pinnick-type oxidation gave N-tosyl -amino acids without epimerization.
Synthesis of Highly Functionalized Pyrrolidines via a Selective Iodide-Mediated Ring Expansion of Methylenecyclopropyl Amides
作者:Mark E. Scott、Mark Lautens
DOI:10.1021/jo802049u
日期:2008.11.7
iodide-mediated, tandem Mannich/cyclization to afford trans-2,3-disubstituted pyrrolidines from methylenecyclopropyl amides in good to excellent yields and selectivities. The reaction scope has been drastically expanded to include a wide array of aromatic, heteroaromatic and alpha,beta-unsaturated imines, as well as a variety of methylenecyclopropyl amides. Additionally, mechanistic studies were carried out
Synthesis of Enantiomerically Pure <i>anti</i>-1,2-Diaryl and <i>syn</i>-1,2-Alkylaryl <i>vic</i>-Selenoamines
作者:José L. García Ruano、Esther Torrente、Inés Alonso、Mercedes Rodriguez、Ana M. Martín-Castro、Alessandro Degl’Innocenti、Lucrezia Frateschi、Antonella Capperucci
DOI:10.1021/jo202611v
日期:2012.2.17
Phenylselenyl benzylcarbanion stabilized by an (S)-2-p-tolylsulfinyl group evolves in a highly stereoselective way in the reactions with (S)-N-(p-tolylsulfinyl)imines at -98 degrees C affording diastereomerically pure 1,2-selenoamino derivatives in good yields. The syn or anti relationship of the obtained compounds depends on the alkyl or aryl character of the imine. They are easily transformed into enantiomerically pure (1R,2S)-1-aryl [or (1S,2S)-1-alkyl]-2-(phenylseleno)-2-phenylethylamines by reaction with t-BuLi and subsequent methanolysis of the generated sulfinamide derivatives with TFA.