Monoaza-12-crown-4 derivatives preparation

When certain long polyethyleneoxy side arms were present, formation of monoaza-15-crown-5 and 18-crown-6 derivatives by cyclization sometimes proved difficult. In such cases,the parent compounds were N-alkylated to give the desired lariat ethers. The parent compounds were obtained from the N-benzyl derivatives, prepared as described previously, which were hydro-genolyzed to the parent macrocycles. Such a procedure was used to prepare a number of monoaza-12-crown-4 derivatives as well (13). 

M -Dialkyldiazacrown ethers and their precursors fcis(alkylamino) derivatives of tri- and tetraethylene glycols were prepared <96CCCC622>. New hydroxy-bearing dibenzo-azocrown ethers have been conveniently prepared utilizing l,3-Ws(2-formylphenoxy)-2-propanol and a diamine, followed by reduction of the intermediate diimine <96P1197>. Fluorescent photoinduced electron transfer sensor 5 with monoaza-18-crown-6 and guanidinium receptor units demonstrated a fluorescence with T -aminobutyric acid in a mixed... 

A spironaphthoxazine derivative incorporating a monoaza-12-crown-4 entity at the 5 -position has been prepared by Kimura el al.19 It is a light-resistant, cation-complexable photochromic compound. 

Chiral monoaza-15-crown-5 derived from D-glucose 92 was shown to be another good catalyst in the asymmetric epoxidation of chalcones with tert-butylhydroper-oxide as the oxidant, with the highest enantioselectivity (94% ee) being reported by Bako (entry 4, Table 11.8) [71]. The tetracyclic C2-symmetric guanidiurn salt 93, which was prepared from (SJ-malic acid by Murphy, also showed excellent enantioselection in the asymmetric epoxidation of chalcone (entry 5) [72]. 

Other monoaza-12-crown-4 derivatives were prepared by using the cyclization method developed by Calverley and Dale (14, 15). This method involves reaction between a primary amine and tetraethylene glycol diiodide. 

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