Aziridines reaction with alkoxides

In the presence of alkoxides chloroform reacts with secondary amines or aziridines to yield a mixture of aminal esters (486), amide acetals (487) and tris(dialkylamino)methanes (488 equation 224). Predominantly aminal esters (489 equation 225) are formed in the reaction of dchloromethyl ether with aziridines and sodium hydioxide. The heterocyclic aminal ester (491 equation 226) was prepared from the perimidine (490) and triethyl orthoformate. ... 

R = Bz) was prepared directly from (143) by treatment with sodium methoxide at room temperature. The JV-acetyl compound (189, R = Ac) also gave (190) with hot, ethanolic sodiiun ethoxide. A distinction between (143) (and its iV-acetyl analog) and (189, R = Bz) (and its A -acetyl analog) was noted in the formation of a mixture of aziridines (188, R = H, Bz, or Ac) and oxazolines C(144) and the 3-methyl analog] from alkoxide reactions on (143), but of the aziridine (190) only, in the reactions of (189) with alkoxides this difference was explained on conformational grounds. Potassium cyanide in A, A -dimethylform-amide converts (143) mainly into (188, R = Bz) the oxazoline (144) is a major by-product. ... 

A short synthesis of (5 ,9 )-(—)-indolizidine 223AB (1806) by Smith and Kim used the silylated dithiane 1847 as a linchpin for the one-pot tandem alkylation with epoxide (- -)-1848 and the N-tosylaziridine (—)-1849 (Scheme 233). The first intermediate is presumably alkoxide 1850, which undergoes a 1,4-Brook rearrangement to 1851 before reaction with the aziridine. The bis-alkylated dithiane (—)-1852 was isolated in... 

The reaction of chloroform with imidazoles > benzimidazoles and secondary amines (especially alicyclic amines) in the presence of alkoxides or hydroxides, as well as the reaction of chlorodifluoro-methane with sodium N-alkyl-iV-arylamides furnishes trisaminomethanes (525) and (526) (Scheme 95), respectively. Aziridine transforms fluorodialkyl sulfide (527) to the orthoamide (528 equation... 

A heterodinuclear rare earth metal SchifF base catalyzes enantioselective desymmetrization of cyclic and acyclic weyo-aziridines with malonates (Scheme 13). The combined use of two rare earth metal sources with different properties, Bronsted basic rare earth metal alkoxide and Lewis acidic rare earth metal triflate, was important to promote the desired ring-opening reactions. The La(0 Pr)3/Yb(OTf)3/SchifFbase complex gave chiral cyclic and acyclic y-amino esters in high yields and high enantiomeric excesses. 

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