Rh(II)-catalysed carbenoid cyclisations in a stereoselective approach to α-quaternary pipecolic acid derivatives
作者:Mioara Andrei、Christian Römming、Kjell Undheim
DOI:10.1016/j.tetasy.2004.03.018
日期:2004.4
derivatives has been carried out by intramolecular rhodium(II)-carbenoid cyclisation reactions with diazoketones in the geminally disubstituted chiron (R)-2-isopropyl-3,6-dimethoxy-2,5-dihydropyrazine. Both enantiomeric pairs of the pipecolic acid derivatives have been prepared from the same chiron. Exclusive chemoselectivity was seen in the rhodium(II)-carbenoid reactions, which occurred at the adjacent