A series of N-sulfinyl dienophiles 1c-i has been screened in asymmetric hetero-Diels-Alder reactions using chiral bis(oxazoline)copper(II) and -zinc(II) triflates. The survey pointed out N-sulfine 1c (R P(O)(OPh)2) as the most promising N-sulfine regarding yield and stereoselectivity (up to 97% ee). The relative configurations, and in one case the absolute configuration, of the HDA adducts were established
使用手性双(
恶唑啉)
铜(II)和-
锌(II)
三氟甲磺酸酯在不对称杂Diels-Alder反应中筛选了一系列N-亚磺酰基二烯亲和体1c-i。该调查指出,就产量和立体选择性(高达97%ee)而言,N-
硫1c(R P(O)(OPh)2)是最有希望的N-
硫。通过X射线分析确定了H
DA加合物的相对构型,在一种情况下是绝对构型。