promising as good dienophiles, which were easily converted into the desired carboxylic derivatives. Bis(pyrazolyl)methanes, which were derived from chiral pyrazoles, showed the activity of chiral catalyst. Particularly 10 mol% of bis(isomenthopyrazol-1,1′-yl)methane (8a) catalyzed enantioselectively the Diels Alder reaction up to 40 % ee by the formation of complex with Mg(ClO4)2.
                                    N-酰基
吡唑类(1)具有良好的二烯亲和性,有望轻松转化为所需的
羧酸衍
生物。衍生自手性
吡唑的双(
吡唑基)
甲烷显示出手性催化剂的活性。通过与Mg(ClO 4)2形成络合物,特别是10 mol%的双(异薄荷基
吡唑-1,1'-基)
甲烷(8a)对映选择性地催化Diels Alder反应达到40%ee 。