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

卡贝烯和类卡贝烯长期以来一直被认为是高活性的碳物种，具有各种独特的反应活性。然而，这些活性物质在有机合成中并没有得到充分利用。究其原因，一是产生卡贝烯和类卡贝烯的前体相当有限，二是该物种的反应性太高，难以控制。为了解决上述问题，我们以α-卤代烷基（或烯基）芳基亚砜为前驱体，采用亚砜-镁交换反应制备了较温和的类镁化合物。α-卤代烷基（或烯基）芳基亚砜的合成很容易，总收率高。以相应的亚砜为原料，用格氏试剂在低温条件下定量合成了类亚砜镁、环丙基类亚砜镁、环丁基类亚砜镁、β-氧化类亚砜镁和烷基化类亚砜镁。它们通常在-60℃以下稳定至少30分钟。每一种类镁化合物都有其独特的反应活性，我们可以从这些活性物质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.