Exploitation of the Chemistry of Magnesium Carbenoids and Their Use in New Synthetic Method for Organic Synthesis

卡宾和类卡宾长期以来被认为是高活性碳物种，其显示出各种独特的反应性。然而，这些活性物种在有机合成中没有得到充分利用。这主要是由于生成卡宾和类卡宾的前体物质有限，以及物种的反应活性太高而难以控制。为了解决上述问题，我们以α-卤代烷基（或烯基）芳基亚砜为前体，通过亚砜-镁交换反应，生成了较为温和的类卡宾镁。α-卤代烷基（或烯基）芳基亚砜的合成方法简单，总收率高。在低温下，由相应的亚砜与格氏试剂以定量产率生成类卡宾镁、环丙基类卡宾镁、环丁基类卡宾镁、β-氧代类卡宾镁和亚烷基类卡宾镁。它们通常在-60℃以下稳定30 min以上。每种镁卡宾都有自己独特的反应活性，我们可以从这些活性物种中发现许多前所未有的反应。

Carbenes and carbenoids have long been known to be highly reactive carbon species that show a variety of unique reactivities. However, those reactive species are not fully used in organic synthesis. The reasons are as follows : one is the precursors for the generation of carbenes and carbenoids are quite limited and the other is that the reactivity of the species is too high to control. In order to solve the problem mentioned above, we used α-haloalkyl (or alkenyl) aryl sulfoxides as the precursors and used sulfoxide-magnesium exchange reaction for generation of much mild magnesium carbenoids. α-Haloalkyl (or alkenyl) aryl sulfoxides are quite easily synthesized in high overall yields. Magnesium carbenoids, cyclopropylmagnesium carbenoids, cyclobutylmagnesium carbenoids, magnesium β-oxido carbenoids, and magnesium alkylidene carbenoids are generated at low temperature from the corresponding sulfoxides with a Grignard reagent in quantitative yields. They were found to be stable usually at below -60℃ for at least 30 min. The each magnesium carbenoids have their own unique reactivities and we could found many unprecedented reactions from these reactive species.