1356563-72-8Relevant academic research and scientific papers
Synthesis of 2-azabicyclo[2.1.0]pentanes by the intramolecular nucleophilic substitution of cyclopropylmagnesium carbenoids with magnesium anilide
Kimura, Tsutomu,Nishimura, Toshiki,Wada, Natsumi,Satoh, Tsuyoshi
, p. 2623 - 2628 (2017)
A variety of 2-azabicyclo[2.1.0]pentanes were synthesized by the intramolecular nucleophilic substitution of cyclopropylmagnesium carbenoids with magnesium anilide. The 1-chlorocyclopropyl p-tolyl sulfoxides possessing an N-aryl-substituted aminomethyl group were prepared from dichloromethyl p-tolyl sulfoxide, α,β-unsaturated carboxylic acid esters, and anilines in four steps. The deprotonation of the amine with t-BuMgCl followed by sulfoxide/magnesium exchange of the sulfoxides with i-PrMgCl led to the generation of the cyclopropylmagnesium carbenoids possessing a magnesium anilide moiety. Subsequent intramolecular nucleophilic substitution of the cyclopropylmagnesium carbenoids occurred in a 4-exo-tet manner to give the 2-azabicyclo[2.1.0]pentanes. The optically active 2-azabicyclo[2.1.0]pentane was synthesized using a p-tolylsulfinyl group as a chiral auxiliary.
Synthesis of 3-azabicyclo[3.1.0]hexanes by insertion of cyclopropylmagnesium carbenoids into an intramolecular C-H bond adjacent to a nitrogen atom
Kimura, Tsutomu,Wada, Natsumi,Tsuru, Takahiro,Sampei, Taro,Satoh, Tsuyoshi
, p. 5952 - 5958 (2015)
Abstract A variety of 3-azabicylo[3.1.0]hexanes were synthesized via 1,5-C-H insertion of cyclopropylmagnesium carbenoids as a key step. 1-Chlorocyclopropyl p-tolyl sulfoxides with an N,N-disubstituted aminomethyl group on the cyclopropane ring were prepared from dichloromethyl p-tolyl sulfoxide, α,β-unsaturated carboxylic acid esters, primary amines, and alkyl halides. Treatment of the sulfoxides with i-PrMgCl generated cyclopropylmagnesium carbenoids, which were inserted into an intramolecular C-H bond adjacent to a nitrogen atom to give 3-azabicyclo[3.1.0]hexanes in yields of up to 94%. The reactivity of the C-H bond toward the insertion increased in the order of NCH3, NCH2CH3, NCH2Ph, and NCH(CH3)2. Optically active 3-azabicyclo[3.1.0]hexane was successfully synthesized using an S-chiral p-tolylsulfinyl group as a chiral auxiliary.
Synthesis, including asymmetric synthesis, of 3-oxabicyclo[3.1.0]hexanes and bicyclo[3.1.0]hexanes by the 1,5-CH insertion of cyclopropylmagnesium carbenoids as the key reaction
Satoh, Tsuyoshi,Tsuru, Takahiro,Ikeda, Shotaro,Miyagawa, Toshifumi,Momochi, Hitoshi,Kimura, Tsutomu
scheme or table, p. 1071 - 1084 (2012/02/14)
The addition reactions of α,β-unsaturated carbonyl compounds with dichloromethyl p-tolyl sulfoxide in the presence of NaHMDS or LDA resulted in the formation of adducts, 1-chlorocyclopropyl p-tolyl sulfoxides bearing a carbonyl group at the 2-position, in almost quantitative yields. The carbonyl group of the adducts was transformed to various ether groups to give 1-chlorocyclopropyl p-tolyl sulfoxides bearing an ether functional group at the 2-position in short steps. Treatment of these products with i-PrMgCl at low temperature afforded cyclopropylmagnesium carbenoids via the sulfoxide-magnesium exchange reaction. 1,5-Carbon-hydrogen insertion (1,5-CH insertion) reaction of the generated magnesium carbenoid intermediates took place to give 3-oxabicyclo[3.1.0]hexanes or bicyclo[3.1.0]hexanes bearing an ether group at the 4-position in moderate to good yields. When this procedure was carried out starting with enantiopure dichloromethyl p-tolyl sulfoxide, enantiopure 3-oxabicyclo[3.1.0]hexanes were obtained in good overall yields. These procedures provide a good way for the synthesis, including asymmetric synthesis, of multisubstituted 3-oxabicyclo[3.1.0]hexanes and bicyclo[3.1.0]hexanes from α,β-unsaturated carbonyl compounds and dichloromethyl p-tolyl sulfoxide in short steps.
