symmetric – i.e. prochiral – diheteroaryl sulfoxides. The latter were treated with a 0.5- or 1.2-fold molar amount of 5:4 mixtures of dilithium (S)-BINOLate and diisobutylmagnesium. This allowed five asymmetric sulfoxide/magnesium exchange reactions to occur. They delivered asymmetric sulfoxides in up to 77 % yield and with up to 88 % ee. Surprisingly, four related diheteroaryl sulfoxides, bis(2-pyridyl)
5 元环杂环被α-
锂化或α-
镁化,以便它们攻击SOCl2 或SO(OMe)2,形成对称的——即前手性——二杂芳基亚砜。后者用0.5-或1.2-倍摩尔量的5:4二
锂(S)-BINOLate和
二异丁基镁的混合物处理。这允许发生五个不对称的亚砜/
镁交换反应。他们以高达 77% 的产率和高达 88% 的 ee 提供不对称亚砜。令人惊讶的是,四种相关的二杂芳基亚砜、双(2-
吡啶基)亚砜和双(3-
吡啶基)亚砜不适合这种交换,而是分解了。