The present application, the general formula ^{R 1 R 2 N-Mg -NR} 3 R 4 · zLiY (II) ^{[R 1, R 2, R 3} , R 4 are independently hydrogen; substituted or unsubstituted aryl or heteroaryl (1 or includes two or more hetero atoms); a linear, branched or cyclic, substituted or unsubstituted alkyl, alkenyl, or is selected from alkynyl, or their silyl derivatives, R ¹ and R ² or R ³ and R ^4, together are part of a cyclic structure, or a polymer, at least one of R ¹ and at least one and R ³ in R ² and R ⁴ is other than hydrogen; Y is F ; Cl; Br; I; CN ; SCN; NCO; HalO n (n = 3 or 4, from Hal is, Cl, is selected from Br and _{I); NO 3; BF 4} ; PF 6; hydrogen; general formula R carboxylate of ^{_X CO 2;} of the general formula ^SR X thiolate; general formula ^oR X of alcoholate _{^{R X P (O) O 2}} ; SCOR X; SCSR X; O n SR X (n = 2 or _3); NO n (n = 2 or 3); and selected from the group consisting of their derivatives; R ^X-represents a substituted or unsubstituted aryl or heteroaryl (including one or more hetero atoms); a linear, branched of Jo or cyclic, substituted or unsubstituted alkyl, alkenyl, alkynyl, or derivatives thereof; a or hydrogen atom, a z> 1. Mixed Mg / Li amide, as well as methods of preparation and these amide of the mixed Mg / Li amide] relates to the use of, for example, as a base.