Iron‐Catalyzed Synthesis of Cyclopropyl Halides

Abstract

Under a halo: Selective iron‐catalyzed hydrodehalogenations of dibromo‐ and dichlorocyclopropanes are effectively realized with tBuMgCl as the reductant. The reactions proceed under mild conditions and exhibit superior selectivities to iron‐free protocols, as no allenes are formed. The sequential combination of base‐mediated dihalocyclopropanation and this mono‐dehalogenation provides straightforward access to substituted monohalocyclopropanes.

Iron Catalysis in Organic Synthesis

“…These conditions have also been applied to the selective monodebromination of 1,1-dibromocyclopropanes (Scheme , eq a) . Slightly higher temperatures and catalyst loadings enabled also the monodechlorination of 1,1-dichlorocyclopropanes (eq b).…”

Recent advances in the syntheses, transformations and applications of 1,1-dihalocyclopropanes

“…70 Allene, which is a common by-product of usual dehalogenation of dihalocyclopropanes was not observed in the reaction. 70 Allene, which is a common by-product of usual dehalogenation of dihalocyclopropanes was not observed in the reaction.…”

“…An efficient Fe-catalyzed protocol for selective monodehalogenation of dihalocyclopropanes 108 with commercially available t-BuMgCl is reported (Scheme 40). 70 Allene, which is a common by-product of usual dehalogenation of dihalocyclopropanes was not observed in the reaction. A iron catalyst was found to be highly tolerant towards a large number of functional groups.…”

Iron oxide catalyzed reduction of acid chlorides to aldehydes with hydrosilanes

“…Efficient iron-catalyzed transformations including carbon-carbon bond forming reactions has been developed to date [15][16][17][18][19]. Regarding iron-catalyzed reductive transformations [20][21][22][23][24][25][26][27][28][29][30][31], iron complexes were found to be active for reductions of carbonyl compounds such as aldehydes [20,21], ketones [20,21], and amides [22]. However, some iron complexes must be prepared before use and they might be unstable for further handling [20,21].…”