Aziridinyl anion

The addition of aziridinyl anions to aldehydes gave the alcohols 31 in good yields15. As with the oxiranyl anions, the diastereoselectivity of the addition reaction could be substantially enhanced by transmetalation of the lithium reagent with chlorotris(dimethylamino)titanium. 

Sulfinyl aziridines (162) were found to undergo a clean metallation by ethyl Grignard with loss of the sulfoxide moiety to give the aziridinyl anions 163, which in turn can be alkylated in the presence of copper(I) iodide to give new elaborated products (164) with the heterocyclic nucleus intact <00TL6495>. 

The chemistry of oxiranyl anions (117) and aziridinyl anions (118) has been reviewed186 and tris-1,2,3-/ -nitrophenylcyclopropcnc has been found to resist conversion to the corresponding anti-aromatic cyclopropenyl anion by deprotonation even though it has been estimated to have a pAa of 32.187... 

Regio- and stereo-selective deprotonation of (V-t-butylsulfonyl-protected terminal aziridines with LiTMP has generated a non-stabilized aziridinyl anion that undergoes in situ or external electrophile trapping under experimentally straightforward conditions to give tran.v-disuhstituted aziridines in good to excellent yields.92... 

The Darzens reaction of the oxazoline 360 with a series of aldimines has been shown to form aziridine 362 in good yields and with high diastereoselectivity <2005X3251>. Deprotonation of the aziridine to form the aziridinyl anion and subsequent reaction with an electrophile provide the highly substituted aziridines 363 in moderate yields. The diphenylphosphinyl group on the nitrogen provides optimal yields in the lithiation reaction (Scheme 94). 

More recently, Hodgson et al. have found that aziridinyl anions can also undergo a diastereoselective intramolecular cyclopropanation reaction to give 2-aminohicyclo[3.1.0]hexenes in good yield <20060L995>. Reversing the addition order so that the aziridine was added dropwise to the hase led to increased yields of the hicyclic amine. When the dienyl-substituted aziridine 386 was used, an 85% yield of the 2-amino hicyclo[3.1.0]hexane 387 was obtained, which contains the potentially useful vinyl cyclopropane moiety (Scheme 98). 

Yamauchi, Y., Kawate, T., Katagiri, T. and Uneyama, K. (2003) Generation and reactions of a-trifluoromethyl stabilized aziridinyl anion, a general synthetic precursor for stereospecific construction of a-amino-a-trifluoromethylated quaternary carbon. Tetrahedron Lett., 44, 6319-6322. 

Yamauchi, Y Kawate, T Katagiri, T Uneyama, K. Trifluoromethyl-stabilized optically active oxiranyl and aziridinyl anions for stereospecific syntheses of trifluoromethylated compounds. Tetrahedron 2003, 59, 9839. 

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