Cyclopropane aldimine

Aziridines have been synthesized, albeit in low yield, by copper-catalyzed decomposition of ethyl diazoacetate in the presence of an inline 260). It seems that such a carbenoid cyclopropanation reaction has not been realized with other diazo compounds. The recently described preparation of 1,2,3-trisubstituted aziridines by reaction of phenyldiazomethane with N-alkyl aldimines or ketimines in the presence of zinc iodide 261 > most certainly does not proceed through carbenoid intermediates rather, the metal salt serves to activate the imine to nucleophilic attack from the diazo carbon. Replacement of Znl2 by one of the traditional copper catalysts resulted in formation of imidazoline derivatives via an intermediate azomethine ylide261). 

W(CO)6 in toluene at room temperature gave the tricyclic adduct 190a in 94% yield after acidic workup. This reaction forms the tungsten-containing azomethine ylide 191, which undergoes the [3 + 2]-cycloaddition with 189a. The rhodium(n)-catalyzed cyclization of the ene-yne-aldimine 192 with alkene 193 into the cyclopropane 194 was reported by Uemura and Ohe (Scheme 32).42c... 

An external aldimine forms with SAM, which is deprotonated to form the quinonoid intermediate. The deprotonated carbon atom attacks the carbon atom adjacent to the sulfur atom to form the cyclopropane ring and release methyl thio-adenosine, the other product. 

During the reaction of the doubly activated allyl halides with primary and secondary amines no 2-amino-substituted cyclopropane derivatives could be isolated, but instead ring-opened products are formed. Primary amines give rise to the formation of aldimines (332) while secondary amines afford formally substitution products (333) . The formation of these products can be explained by ring cleavage of non-isolable electrophilic 2-aminocyclopropanes (331) as outlined in equation 104. 

Alper, RB., Meyers, C., Lerchner, A., Siegel, D.R., and Carreira, E.M., Eacile, novel methodology for the synthesis of spiro[pyrrolidin-3,3 -oxindoles] catalyzed ring expansion reactions of cyclopropanes by aldimines, Angewandte Chemie-Intemational Edition 38 (21), 3186, 1999. 

The first study on the structure of imidoyl radicals dates back to 1973 [11], when Danen described the ESR spectra of the radicals obtained by irradiation of cyclopropane solutions of some aldimines and di-/er -butyl peroxide. On the basis of the low g-values (2.0016) and the jff-hydrogen hyperfine splittings, the authors claimed that imidoyls are cr-radicals with a non-linear arrangement about the N=C-C bond. The facile abstraction of the aldiminic hydrogen, and hence the remarkable stabilization of imidoyl radicals, was explained by the intervention of the mesomeric forms 3a and 3b (Scheme 5), in which the unpaired electron is stabilized by interaction with the lone pair on nitrogen. 

Substituted cyclopropane-1,1-dicarboxylie esters undergoes ring opening and dimerization.Efficient coupling of two aldimine molecules or aldimines with carbonyl compounds (imine slowly added to the ketone and reagents) has been carried out with... 

Diesters.—Michael addition of malonic ester enolates to chiral a/3-unsaturated aldimines (obtained from optically pure a-amino-acids) gives, after hydrolysis, aldehyde-diesters (125) in variable chemical (26—54%) and optical (36—86%) yields. The amino-acid components are recovered optically pure. Attack of simple nucleophiles on the bromoalkylidene malonate (126) gives cyclopropane diesters (127) in good yields. A ready, five-step route to the bicyclo[l,l,0]butane triester (128) has been described. ... 

CuHj N]- (CH3)3CN=CC6H5 Reaction of TBO with the appropriate aldimine/ Cyclopropane EPR/ 210 2.0015 83Davl... 

---