Preparation of 2,6-bis(<i>l</i>-menthopyrzol-3-yl)pyridines and their catalytic activity for asymmetric diels alder reaction
作者:Choji Kashima、Saori Shibata、Hiroyo Yokoyama、Takehiko Nishio
DOI:10.1002/jhet.5570400505
日期:2003.9
of 3-phenyl-l-menthopyrazole (1b) and C2 symmetric ligand in the molecule, should form the C2 symmetric complex in situ with Zn(OTf)2 or Ni(ClO4)2•6H2O. The subsequent complex catalyzed the Diels Alder reaction of 1-acryloyl-3,5-dimethylpyrazole (11a) with cyclopentadiene (12) enantioselectively up to 75 % ee.
由1-薄荷酮制备3-芳基-1-薄荷脑吡唑1和2及相关化合物,并讨论了它们的对映选择性活性作为手性配体。在这一系列化合物中,具有3-苯基-1-薄荷脑吡唑(1b)和C 2对称配体的结构特征的2,6-双(2-甲基-1-薄荷脑吡唑-3-基)吡啶(8a)在分子中,应与Zn(OTf)2或Ni(ClO 4)2 •6H 2原位形成C 2对称络合物O.随后的络合物催化1-丙烯酰基-3,5-二甲基吡唑(11a)与环戊二烯(12)的对映选择性Diels Alder反应,对映体选择性高达75%ee。